Anaplasmosis, symptomatic (alternative agent) (off-label use):
Note: Reserve use for patients with severe allergy or intolerance to doxycycline. Rifampin is not effective for Rocky Mountain spotted fever or Lyme disease. If concurrent Lyme disease is suspected, use as part of an appropriate combination regimen (CDC [Biggs 2016]; IDSA [Wormser 2006]).
Oral: 300 mg twice daily for 7 to 10 days (CDC [Biggs 2016]; IDSA [Wormser 2006]).
Bartonella spp. infections (off-label use):
Bacteremia with or without endocarditis (alternative adjunctive agent when gentamicin cannot be used): Oral, IV: 300 mg twice daily in combination with doxycycline for 14 days, followed by doxycycline monotherapy (Rolain 2004; Spach 2020a; Spach 2020b). Some experts do not suggest rifampin as part of the regimen for patients with HIV and bacteremia without endocarditis (HHS [OI adult] 2020).
Other severe infection (including CNS infection) in patients with HIV: Oral, IV: 300 mg twice daily as part of an appropriate combination regimen. Duration of therapy is at least 3 months and depends on clinical course (HHS [OI adult] 2020). Note: For CNS infection, use of adjunctive rifampin is optional (HHS [OI adult] 2020).
Cat scratch disease, lymphadenitis (alternative agent): Oral: 300 mg twice daily for 7 to 10 days (Spach 2020c).
Cat scratch disease, disseminated in patients without HIV (hepatosplenic, prolonged systemic febrile illness, CNS infection, neuroretinitis): Oral, IV: 300 mg twice daily as part of an appropriate combination regimen. Duration is 10 to 14 days for hepatosplenic disease or prolonged systemic febrile illness and 4 to 6 weeks for CNS infection or neuroretinitis (Rolain 2004; Spach 2020c).
Brucellosis (off-label use):
Treatment: Oral: 600 to 900 mg once daily as part of an appropriate combination regimen. Duration is 6 weeks for uncomplicated nonfocal infection and at least 12 weeks for spondylitis, neurobrucellosis, and endocarditis (Alp 2008; Ariza 2007; Bosilkovski 2020; CDC 2017; Jia 2017; Skalsky 2008; Solera 1999; WHO [Corbel 2006]; Zheng 2018).
Postexposure prophylaxis (high-risk laboratory exposure): Note: For exposure to Brucella abortus RB51, use an alternative prophylactic regimen due to resistance.
Oral: 600 mg once daily in combination with doxycycline for 3 weeks (Bosilkovski 2020; CDC 2017).
Cholestatic pruritus (alternative agent) (off-label use):
Note: Avoid use in patients with a baseline bilirubin >2.5 mg/dL (AASLD [Lindor 2019]).
Oral: 150 to 300 mg twice daily (Poupon 2021).
Endocarditis, treatment (off-label use):
Staphylococcus spp. or early (<1 year) culture negative (prosthetic valve): Oral, IV: 900 mg/day in 3 equally divided doses as part of an appropriate combination regimen for ≥6 weeks; delay initiation of rifampin until 3 to 5 days after initiation of the other agents (AHA [Baddour 2015]; IDSA [Liu 2011]; Karchmer 2020).
Hidradenitis suppurativa, moderate to severe (alternative agent) (off-label use):
Oral: 600 mg/day in 1 or 2 divided doses in combination with clindamycin for 10 to 12 weeks (Alikhan 2019; Dessinioti 2016; Gener 2009; Gulliver 2016; van der Zee 2009).
Leprosy (off-label use):
Oral: 600 mg once daily as part of an appropriate combination regimen for 12 months for tuberculoid (paucibacillary) disease and 24 months for lepromatous (multibacillary) disease (NHDP/HRSA 2018). Note: Rifampin is given once monthly if coadministered with prednisone (NHDP/HRSA 2018). For resource-limited settings, the World Health Organization recommends 600 mg once monthly as part of an appropriate combination regimen for 6 months (paucibacillary) or 12 months (multibacillary) (WHO 2018).
Meningococcal disease, chemoprophylaxis after close contact with a patient with invasive disease (off-label use):
Oral: 600 mg twice daily for 2 days. Note: Administer prophylaxis as soon as possible following exposure (ideally <24 hours after identification of index patient). Close contacts include persons with prolonged exposure (≥8 hours) in close proximity (<3 feet) to index patient or direct exposure to oral secretions (eg, household contacts, childcare center contacts) (AAP [Red Book 2015]; ACIP [Bilukha 2005]; ACIP [Cohn 2013]; Gardner 2006).
Mycobacterial (nontuberculous) (eg, M. avium complex) infection (off-label use):
Pulmonary disease, nonsevere noncavitary nodular/bronchiectatic disease in patients without cystic fibrosis: Oral: 600 mg 3 times weekly as part of an appropriate combination regimen (ATS/ERS/ESCMID/IDSA [Daley 2020]; BTS [Haworth 2017]).
Pulmonary disease, severe nodular/bronchiectatic disease, cavitary disease, or disease in patients with cystic fibrosis: Oral: 600 mg once daily as part of an appropriate combination regimen; reduce dose to 450 mg once daily for patients weighing <50 kg (ATS/ERS/ESCMID/IDSA [Daley 2020]; CFF/ECFS [Floto 2016]).
Duration of therapy: Continue treatment until patient is culture negative on therapy for ≥1 year (ATS/ERS/ESCMID/IDSA [Daley 2020]; BTS [Haworth 2017]; CFF/ECFS [Floto 2016]).
Staphylococcus spp. infections, including bone and joint and CNS (adjunctive agent) (off-label use):
Note: Used primarily in the setting of retained hardware or other prosthetic material for activity against biofilm formation (IDSA [Liu 2011]; Zimmerli 1998; Zimmerli 2019).
Oral, IV: 600 mg once daily or 300 to 450 mg twice daily in combination with an appropriate antistaphylococcal agent(s). Duration varies based on patient-specific factors, infection site, and intervention (Baddour 2020; IDSA [Liu 2011]). Some experts suggest delaying initiation of rifampin until several days after initiation of other antistaphylococcal agents (Berbari 2020; Osmon 2020).
Streptococcus (group A) chronic carriage (off-label use):
Note: Most individuals with chronic carriage do not require antibiotics (IDSA [Shulman 2012]).
Oral: 600 mg/day in 1 or 2 divided doses for the last 4 days of treatment in combination with penicillin V (Chaudhary 1985; IDSA [Shulman 2012]) or for 4 days in combination with single-dose IM benzathine penicillin G (IDSA [Shulman 2012]; Tanz 1985).
Tuberculosis, active (drug susceptible):
Note: Always administer in combination with other antitubercular drugs (ATS/CDC/IDSA [Nahid 2016]).
Oral, IV:
Initial intensive phase: 10 mg/kg (maximum dose: 600 mg) once daily (or 5 days per week by directly observed therapy [DOT]) as part of a standard 4-drug regimen for 2 months (ATS/CDC/IDSA [Nahid 2016]).
Continuation phase: 10 mg/kg (maximum dose: 600 mg) once daily (or 5 days per week by DOT) in combination with isoniazid for at least 4 months or longer for cavitary disease with positive cultures (7 months), bone and joint disease (6 to 9 months), and CNS disease (≥12 months) (ATS/CDC/IDSA [Nahid 2016]).
Alternative dosing intervals: Daily or 5-times-weekly dosing is preferred, particularly during the intensive phase. If neither is feasible, alternatives in order of preference are: daily (or 5-times-weekly) dosing for the intensive phase followed by 3-times-weekly dosing during the continuation phase; 3-times-weekly dosing for the duration of treatment; and daily dosing for 2 weeks followed by twice-weekly dosing. Use DOT for <7 days/week dosing (ATS/CDC/IDSA [Nahid 2016]).
Tuberculosis, latent infection:
Oral: 10 mg/kg (maximum dose: 600 mg) once daily as a single agent for 4 months (HHS [OI adult 2020]; NTCA/CDC [Sterling 2020]) or in combination with isoniazid for 3 months (NTCA/CDC [Sterling 2020]).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
The renal dosing recommendations are based upon the best available evidence and clinical expertise. Senior Editorial Team: Bruce Mueller, PharmD, FCCP, FASN, FNKF; Jason A. Roberts, PhD, BPharm (Hons), B App Sc, FSHP, FISAC; Michael Heung, MD, MS.
Note: At rifampin doses ≤600 mg/day, reduced clearance by the kidney is compensated for by biliary excretion. However, at rifampin doses ≥900 mg/day, the hepatic excretory pathway is saturated and higher concentrations of rifampin are noted in patients with reduced kidney function (Kenny 1981).
Altered kidney function:
CrCl >15 mL/minute: No dosage adjustment necessary (expert opinion).
CrCl <15 mL/minute: No dosage adjustment necessary for usual indication-specific doses ≤600 mg/day. For usual indication-specific doses ≥900 mg/day, consider limiting dose to 600 mg/day or monitoring more closely for adverse effects (Kenny 1981; expert opinion) except when used for meningococcal chemoprophylaxis (no adjustment necessary due to short duration of therapy) (expert opinion).
Hemodialysis, intermittent (thrice weekly): Not significantly dialyzable (Malone 1999); no dosage adjustment necessary for usual indication-specific doses ≤600 mg/day. For usual indication-specific doses ≥900 mg/day, consider limiting dose to 600 mg/day or monitoring more closely for adverse effects (Kenny 1981; expert opinion) except when used for meningococcal chemoprophylaxis (no adjustment necessary due to short duration of therapy) (expert opinion).
Peritoneal dialysis: Not significantly dialyzable (Ahn 2003); no dosage adjustment necessary for usual indication-specific doses ≤600 mg/day. For usual indication-specific doses ≥900 mg/day, consider limiting dose to 600 mg/day or monitoring more closely for adverse effects (Kenny 1981; expert opinion) except when used for meningococcal chemoprophylaxis (no adjustment necessary due to short duration of therapy) (expert opinion).
CRRT: No dosage adjustment necessary (expert opinion).
PIRRT (eg, sustained, low-efficiency diafiltration): No dosage adjustment necessary (Strunk 2016; expert opinion).
Hepatic impairment prior to treatment initiation:
There are no dosage adjustments provided in manufacturer's labeling; use with caution.
Hepatotoxicity during treatment:
New or worsening hepatic damage: Discontinue rifampin.
(For additional information see "Rifampin (rifampicin): Pediatric drug information")
Note: Rifampin monotherapy is rarely indicated; most indications require combination therapy. Dosing presented in mg/kg/dose and mg/kg/day; use caution.
Anaplasmosis, mild, symptomatic (alternative agent):
Note: Reserve use for patients with severe allergy or intolerance to doxycycline. Rifampin is not effective for Rocky Mountain spotted fever or Lyme disease. If concurrent Lyme disease is suspected, use as part of an appropriate combination regimen (CDC [Biggs 2016]; IDSA [Wormser 2006]).
Infants, Children, and Adolescents: Limited data available: Oral: 20 mg/kg/day in 2 divided doses for 7 to 10 days; maximum dose: 300 mg/dose (CDC [Biggs 2016]; IDSA [Wormser 2006]).
Brucellosis, treatment: Limited data available: Children and Adolescents: Oral: 15 to 20 mg/kg/day in 1 to 2 divided doses as part of an appropriate combination regimen; maximum daily dose: 900 mg/day. Duration is ≥6 weeks and dependent on patient-specific factors including site of infection and presence of complications (Bosilkovski 2015; Bradley 2021; CDC 2017; Red Book [AAP 2018]).
Catheter (peritoneal dialysis); exit-site or tunnel infection: Limited data available: Infants, Children, and Adolescents: Oral: 10 to 20 mg/kg/day divided into 2 doses as part of an appropriate combination regimen. Maximum dose: 600 mg/dose (ISPD [Warady 2012]). Note: Should not be used as monotherapy or routinely used in areas where tuberculosis (TB) is endemic.
Cholestatic pruritus, persistent: Limited data available: Infants ≥4 months, Children, and Adolescents: Oral: 4 to 10 mg/kg/day in 2 divided doses; maximum daily dose: 600 mg/day (Cynamon 1990; El-Karaksy 2007; Gregorio 1993; Yerushalmi 1999). If no response, may increase dose by 2 mg/kg/day every 2 weeks to a maximum dose of 20 mg/kg/day (El-Karaksy 2007).
Endocarditis: Limited data available: Note: Use as part of an appropriate combination regimen.
Empiric therapy or culture-negative endocarditis (prosthetic valve/material) (AHA [Baltimore 2015]):
Early (≤1 year) prosthetic valve infection or nosocomial infection associated with vascular cannulation: Children and Adolescents: Oral, IV: 20 mg/kg/day divided every 8 hours; maximum daily dose: 900 mg/day.
Late (>1 year) prosthetic valve infection: Children and Adolescents: Oral, IV: 15 to 20 mg/kg/day divided every 12 hours; maximum daily dose: 600 mg/day.
MRSA endocarditis (prosthetic valve): Infants, Children, and Adolescents: Oral, IV: 15 mg/kg/day divided every 8 hours; maximum daily dose: 900 mg/day (IDSA [Liu 2011]).
H. influenzae disease, chemoprophylaxis after close contact with a patient with invasive disease: Infants, Children, and Adolescents: Oral: 20 mg/kg/day once daily for 4 days; maximum dose: 600 mg/dose (Kliegman 2020; Red Book [AAP 2018]).
Leprosy: Limited data available: Note: In the United States, it is strongly recommended to contact the National Hansen's Disease Program for management of leprosy in children (NHDP/HRSA 2018).
Children and Adolescents: Oral: 10 to 20 mg/kg/day once daily; maximum dose: 600 mg/dose. If used in combination with prednisone, rifampin should be administered once monthly. Should be given as part of an appropriate combination regimen for 12 months for tuberculoid (paucibacillary) disease and 24 months for lepromatous (multibacillary) disease (NHDP/HRSA 2018); in resource-limited settings, the World Health Organization allows for shorter durations of monthly dosing for 6 months (paucibacillary) or 12 months (multibacillary) (WHO 2018).
Meningococcal disease, chemo prophylaxis after close contact with a patient with invasive disease: Infants, Children, and Adolescents: Oral: 20 mg/kg/day in divided doses every 12 hours for 2 days; maximum dose: 600 mg/dose.
Mycobacterium avium complex infection: Limited data available:
Pulmonary disease, nonsevere noncavitary nodular/bronchiectatic disease in patients without cystic fibrosis: Children and Adolescents: Oral: 15 mg/kg/dose 3 times weekly as part of an appropriate combination regimen; maximum dose: 450 mg in patients weighing <50 kg; maximum dose: 600 mg in patients weighing ≥50 kg (BTS [Haworth 2017]; Red Book [AAP 2018]). Note: Three-times-weekly dosing has been shown to be as effective as daily dosing in adults with mild to moderate disease with fewer adverse events (Red Book [AAP 2018]).
Pulmonary disease, severe nodular/bronchiectatic disease, cavitary disease, or disease in patients with cystic fibrosis: Children and Adolescents: Oral: 10 to 20 mg/kg/day once daily as part of an appropriate combination regimen; maximum dose: 450 mg in patients weighing <50 kg; maximum dose: 600 mg in patients weighing ≥50 kg (BTS [Haworth 2017]; CFF/ECFS [Floto 2016]). Note: Daily dosing is recommended in patients with cystic fibrosis due to lack of data to support intermittent dosing and uncertainty regarding absorption and lung penetration in this population (CFF/ECFS [Floto 2016]).
Duration of therapy: Continue treatment until patient is culture negative on therapy for ≥1 year (BTS [Haworth 2017]; CFF/ECFS [Floto 2016]).
Peritonitis (peritoneal dialysis), treatment: Infants, Children, and Adolescents: Oral: 10 to 20 mg/kg/day divided into 2 doses in combination with other appropriate antibiotics; maximum dose: 600 mg/dose (ISPD [Warady 2012]).
Streptococcus (group A) chronic carriage (IDSA [Shulman 2012]): Limited data available: Note: Most individuals with chronic carriage do not require antibiotics (IDSA [Shulman 2012]).
In combination with oral penicillin V: Children and Adolescents: Oral: 20 mg/kg/day once daily for the last 4 days of treatment; maximum daily dose: 600 mg/day.
In combination with intramuscular benzathine penicillin G: Children and Adolescents: Oral: 20 mg/kg/day in 2 divided doses for 4 days; maximum daily dose: 600 mg/day.
Tuberculosis, active (drug-susceptible); treatment (ATS/CDC/IDSA [Nahid 2016]):
Note: Always administer in combination with other antitubercular drugs (ATS/CDC/IDSA [Nahid 2016]. Currently recommended doses in guideline, particularly those on the lower end of the range, may not achieve desired exposure (Aruldhas 2019; Hiruy 2015; Kwara 2016; Yang 2018). Doses of 20 to 30 mg/kg/dose have been recommended for infants and young children or for treating disseminated tuberculosis or tuberculous meningitis (Red Book [AAP 2018]).
Initial intensive phase: Note: Administer part of a standard 4-drug regimen for 2 months.
Infants, Children, and Adolescents <15 years weighing ≤40 kg: Oral, IV: 10 to 20 mg/kg/dose once daily (or 5 days/week by directly observed therapy [DOT]); maximum dose: 600 mg/dose.
Children and Adolescents <15 years weighing >40 kg or Adolescents ≥15 years: Oral, IV: 10 mg/kg/dose once daily (or 5 days/week by DOT); maximum dose: 600 mg/dose.
Continuation phase: Note: Administer in combination with isoniazid for ≥4 months; continuation phase duration should be longer for cavitary disease with positive cultures at completion of intensive phase (7 months), bone and joint disease (≥4 to 7 months), and CNS disease (7 to 10 months).
Infants, Children, and Adolescents <15 years weighing ≤40 kg: Oral, IV: 10 to 20 mg/kg/dose once daily (or 5 days/week by DOT); maximum dose: 600 mg/dose.
Children and Adolescents <15 years weighing >40 kg or Adolescents ≥15 years: Oral, IV: 10 mg/kg/dose once daily (or 5 days/week by DOT); maximum dose: 600 mg/dose.
Alternative dosing intervals: Daily or 5-times-weekly dosing is preferred, particularly during the intensive phase and in patients with HIV. If neither is feasible, alternatives in order of preference are: Daily (or 5-times-weekly) dosing for the intensive phase followed by 3-times-weekly dosing during the continuation phase; 3-times-weekly dosing for the duration of treatment; and daily dosing for 2 weeks followed by twice-weekly dosing. Twice-weekly dosing should not be used in patients with HIV, who are smear-positive, or who have cavitary disease. Directly observe therapy for any regimen that is <7 days/week dosing.
Tuberculosis, latent infection; treatment: Infants, Children, and Adolescents: Independent of HIV status: Oral: 15 to 20 mg/kg/day once daily; maximum dose: 600 mg/dose; use in combination with isoniazid for 3 months or as monotherapy for 4 months (Diallo 2018; HHS [pediatric OI] 2019; NTCA/CDC [Sterling 2020]; Red Book [AAP 2018]). Higher doses of 20 to 30 mg/kg/dose have been recommended for infants and young children (Red Book [AAP 2018]).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
There are no dosage adjustments provided in the manufacturer's labeling; however, based on experience in adults, dosage adjustment is likely unnecessary.
Baseline hepatic impairment: There are no dosage adjustments provided in the manufacturer's labeling; use with caution. If hepatic function worsens, discontinue therapy.
Hepatotoxicity during therapy: Discontinue therapy.
Refer to adult dosing.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Capsule, Oral:
Rifadin: 150 mg [DSC], 300 mg [DSC] [contains brilliant blue fcf (fd&c blue #1), corn starch, fd&c red #40]
Generic: 150 mg, 300 mg
Solution Reconstituted, Intravenous [preservative free]:
Rifadin: 600 mg (1 ea)
Rifadin: 600 mg (1 ea) [contains sodium formaldehyde sulfoxylate]
Generic: 600 mg (1 ea)
Yes
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Capsule, Oral:
Rifadin: 150 mg [DSC], 300 mg [DSC] [contains brilliant blue fcf (fd&c blue #1), fd&c red #40]
Rofact: 150 mg, 300 mg
IV: Administer IV preparation by slow IV infusion over 30 minutes to 3 hours at a final concentration not to exceed 6 mg/mL. Do not administer IM or SUBQ.
May be an irritant; avoid extravasation. Restart infusion at another site if extravasation occurs.
Oral: Administer on an empty stomach (ie, 1 hour prior to, or 2 hours after meals or antacids) to increase total absorption. The compounded oral suspension must be shaken well before using. May mix contents of capsule with applesauce or jelly.
Oral: Administer on an empty stomach with a glass of water (ie, 1 hour prior to or 2 hours after meals) to increase total absorption (food may delay and reduce the amount of rifampin absorbed). The compounded oral suspension must be shaken well before using. May mix contents of capsule with applesauce, pudding, or other semisoft foods (Red Book [AAP 2018]; manufacturer's labeling).
Parenteral: Administer by slow IV infusion over 30 minutes to 3 hours. Do not administer IM or SUBQ. Avoid extravasation.
Meningococcal prophylaxis: Treatment of asymptomatic carriers of Neisseria meningitidis to eliminate meningococci from the nasopharynx.
Tuberculosis: Treatment of latent or active tuberculosis (in combination with other agents, when appropriate).
Anaplasmosis, symptomatic; Bartonella spp. infections; Brucellosis; Cholestatic pruritus; Endocarditis, treatment; Hidradenitis suppurativa, moderate to severe; Leprosy; Meningococcal disease, chemoprophylaxis after close contact with a patient with invasive disease; Mycobacterial (nontuberculous) infection; Staphylococcus spp. infections, including bone and joint and CNS; Streptococcus (group A) chronic carriage
Rifadin may be confused with Rifater, Ritalin
RifAMPin may be confused with ribavirin, rifabutin, Rifamate, rifapentine, rifAXIMin
Clostridioides difficile infection (CDI) has occurred, including Clostridioides difficile-associated diarrhea (in one case in a patient receiving concurrent clindamycin) (Ref) and Clostridioides difficile colitis. Antituberculosis medications, such as rifampin have rarely been associated with CDI. Additionally, rifampin may decrease the risk of CDI from higher risk antibiotics (eg, clindamycin) and has been used in the treatment of CDI (Ref).
Onset: Varied; may start on the first day of antibiotic therapy or up to 3 months postantibiotic (Ref).
Risk factors:
• Antibiotic exposure (highest risk factor) (Ref)
• Type of antibiotic (Ref)
• Long durations in a hospitalization or other health care setting (recent or current) (Ref)
• Older adults (Ref)
• Immunocompromised conditions (Ref)
• A serious underlying condition (Ref)
• GI surgery/manipulation (Ref)
• Antiulcer medications (eg, proton pump inhibitors and H2 blockers) (Ref)
• Chemotherapy (Ref)
Decreased hemoglobin, disorder of hemostatic components of blood (vitamin K-dependent), disseminated intravascular coagulation, eosinophilia, hemolysis, hemolytic anemia, hemorrhage, leukopenia, thrombocytopenia (especially with high-dose therapy) have been reported (Ref).
Mechanism: Not clearly established; likely immunologic (Ref).
Onset: Varied; with intermittent dosing, reactions have occurred within 3 to 6 months (Ref).
Risk factors:
• Intermittent exposure (Ref)
Hepatotoxicity of hepatocellular, cholestatic, and mixed patterns have been reported; may include asymptomatic abnormal hepatic function tests, isolated jaundice or hyperbilirubinemia, symptomatic self-limited hepatitis, or fulminant hepatic failure and death. Severe reactions, including fatalities, have occurred in patients with preexisting hepatic failure and in patients receiving concurrent hepatotoxic agents.
Mechanism: Not clearly established; possible mechanisms include: Idiosyncratic metabolic products that are either directly toxic or induce an immunologic reaction (Ref) or hypersensitivity (Ref).
Onset: Varied; typically, onset of injury is within the first 1 to 6 weeks of initiation (Ref).
Risk factors:
• Long-term therapy (Ref)
• Age >60 years (Ref)
• Alcohol use disorder (Ref)
• Concurrent use of other hepatotoxic agents (eg, isoniazid, pyrazinamide) (Ref)
• Females (Ref)
• Low body mass index (Ref)
• Malnutrition (Ref)
• Preexisting liver disease (eg, chronic viral hepatitis) (Ref))
• HIV (Ref)
Hypersensitivity reactions, both immediate (urticaria, angioedema, anaphylaxis) (Ref) and delayed have been reported. Flu-like symptoms or more severe shock-like syndrome may also occur (Ref). Delayed hypersensitivity reactions range from maculopapular skin rash (Ref) and fixed drug eruption (Ref) to rare severe cutaneous adverse reactions, including acute generalized exanthematous pustulosis (Ref), drug reaction with eosinophilia and systemic symptoms (DRESS) (Ref), Stevens-Johnson syndrome, and toxic epidermal necrolysis (Ref). Since rifampin is usually administered as part of a multidrug regimen, causality is difficult to determine in most cases (Ref). Hypersensitivity angiitis (Ref) and lichenoid eruption (Ref) have also occurred.
Mechanism: Immediate hypersensitivity reactions: Non–dose-related; likely immunologic (ie, IgE-mediated, with specific antibodies formed against a drug allergen following initial exposure) (Ref), although angioedema may be caused by a non–IgE-mediated mechanism (Ref). The flu-like syndrome may be caused by circulating antibodies complexing with rifampin (Ref) or direct toxic effect of the drug (Ref). Delayed hypersensitivity reactions: Non–dose-related; immunologic (ie, involving a T-cell mediated drug-specific immune response) (Ref).
Onset: Immediate hypersensitivity reactions: Rapid; generally occur within 1 hour of administration but may occur up to 6 hours after exposure (Ref). Some cases of urticaria associated with rifampin have been delayed occurring 2 to 3 weeks after initiation of drug (Ref). Flu-like syndrome generally occurs within 1 to 4 hours (Ref). Delayed hypersensitivity reactions: Varied; typically occur days to 8 weeks after drug exposure (Ref), but may occur more rapidly (usually within 1 to 4 days) upon reexposure (Ref).
Risk factors:
• Dose: Flu-like syndrome is considered dose-dependent (Ref)
• Intermittent regimen: Flu-like syndrome occurs more frequently with intermittent regimens (Ref)
• Age >60 years (Ref)
• HIV (Ref)
• Cross-reactivity: Conflicting reports of cross-reactivity with rifabutin (Ref)
Potentially fatal interstitial pulmonary disease and/or pneumonitis has been reported rarely (Ref). Patients with rifampin-induced pneumonitis typically present with low-grade fever and shortness of breath with or without cough (Ref).
Mechanism: Unknown; possibly immunologic (Ref).
Onset: Pneumonitis: Varied; 3 days to 13 weeks in a bimodal pattern with early and late onset but difficult to determine as fever is a common symptom in patients undergoing tuberculosis therapy (Ref).
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.
Postmarketing:
Cardiovascular: Decreased blood pressure, facial edema (Holdiness 1989), flushing, hypersensitivity angiitis (Kim 2010), peripheral edema, shock (Luzzati 2007)
Dermatologic: Acute generalized exanthematous pustulosis (Azad 2006), cutaneous lupus erythematosus (Patel 2001), erythema multiforme, lichenoid eruption (Shahul 2016), pemphigoid reaction, pruritus (Farah 2012), psoriasiform eruption (Feng 2020), skin rash (Farah 2012; Shin 2021), Stevens-Johnson syndrome (Collado-Chagoya 2019), toxic epidermal necrolysis (Collado-Chagoya 2019), urticaria
Endocrine & metabolic: Adrenocortical insufficiency (Denny 2016; Elansary 1983), increased uric acid, menstrual disease
Gastrointestinal: Abdominal cramps, anorexia, cholestasis, Clostridioides difficile associated diarrhea (Bessaleli 2018), Clostridioides difficile colitis, diarrhea, epigastric discomfort, flatulence, glossalgia, heartburn, nausea, staining of tooth (Ayaslioglu 2005), vomiting
Genitourinary: Hematuria (Covic 2004; Martins 2013), hemoglobinuria (Covic 2004)
Hematologic & oncologic: Acute intravascular hemolysis (Sanwal 2020), agranulocytosis (Andres 2017), decreased hemoglobin (Havey 2012; Sveroni 2018), disorder of hemostatic components of blood (vitamin K-dependent) (Havey 2012), disseminated intravascular coagulation (Havey 2012), eosinophilia, hemolysis (Havey 2012; Sveroni 2018), hemolytic anemia (Havey 2012; Sveroni 2018), hemorrhage (Havey 2012), leukopenia, thrombocytopenia (especially with high-dose therapy) (Forget 2006), thrombotic microangiopathy (including hemolytic-uremic syndrome and thrombotic thrombocytopenic purpura) (Gupta 2005)
Hepatic: Abnormal hepatic function tests (Tostmann 2008), hepatic cirrhosis (Tostmann 2008), hepatic failure (Tostmann 2008), hepatitis (including shock-like syndrome with hepatic involvement) (Tostmann 2008), hepatotoxicity (Nelson 2014), hyperbilirubinemia (Tostmann 2008), jaundice (Tostmann 2008)
Hypersensitivity: Anaphylaxis (Syrigou 2016), angioedema (Farah 2012), fixed drug eruption (Mimouni 1990)
Immunologic: Drug reaction with eosinophilia and systemic symptoms (Brockhaus 2019)
Nervous system: Ataxia, behavioral changes, cerebral hemorrhage (Koboyashi 2002), confusion, dizziness, drowsiness, fatigue, headache, lack of concentration, myasthenia, numbness, psychosis (Salafia 1992), sore mouth
Neuromuscular & skeletal: Limb pain, myopathy (Forget 2006; Jenkins 1981)
Ophthalmic: Conjunctivitis
Renal: Acute interstitial nephritis (Rossert 2001), acute renal injury, increased blood urea nitrogen, renal insufficiency, renal tubular necrosis (Forget 2006)
Respiratory: Dyspnea, flu-like symptoms (Luzzati 2007), interstitial pulmonary disease, pneumonitis (Ata 2020; Koma 2013), wheezing
Miscellaneous: Fever, paradoxical reaction (recurrence or appearance of new infection symptoms; may be transient)
Hypersensitivity to rifampin, any rifamycins, or any component of the formulation; concurrent use of atazanavir, darunavir, fosamprenavir, praziquantel, ritonavir/saquinavir, saquinavir, or tipranavir.
Canadian labeling: Additional contraindications (not in US labeling): Jaundice associated with reduced bilirubin excretion; premature and newborn infants; breastfeeding women; hepatic function impairment.
Concerns related to adverse effects:
• Coagulopathy: May cause vitamin K-dependent coagulation disorders and bleeding. Monitor coagulation tests during treatment in patients at risk of vitamin K deficiency (eg, chronic liver disease, poor nutritional status, prolonged use of antibacterial agents or anticoagulants). Consider discontinuation if abnormal coagulation tests and/or bleeding occurs; consider supplemental vitamin K administration when appropriate.
• Dermatologic reactions: Cases of severe cutaneous adverse reactions (SCAR) such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), acute generalized exanthematous pustulosis (AGEP), and drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome have been reported. Discontinue treatment immediately and institute appropriate therapy if signs or symptoms of SCAR develop.
• Flu-like syndrome: Regimens of >600 mg once or twice weekly in adults have been associated with a high incidence of adverse reactions including a flu-like syndrome.
• Hematologic effects: May cause thrombocytopenia, leukopenia, or anemia with regimens >600 mg once or twice weekly in adults.
• Hepatotoxicity: Hepatotoxicity of hepatocellular, cholestatic, and mixed patterns has been reported; may include asymptomatic elevations in liver enzymes, isolated jaundice/hyperbilirubinemia, symptomatic self-limited hepatitis, or fulminant liver failure and death. Severe reactions, including fatalities, have occurred in patients with preexisting hepatic failure and in patients receiving concomitant hepatotoxic agents. Fatal drug-induced liver injury occurring within a few days to a few months has also been reported, especially when used in combination with other antituberculosis therapy. Most cases resolved with discontinuation of therapy; rarely may progress to acute liver failure requiring liver transplantation. Patients with impaired liver function should only be given rifampin when medically indicated and with close monitoring; discontinue use if hepatocellular damage occurs or worsens. Do not use in patients with a history of rifampin-induced liver injury.
• Hypersensitivity: Hypersensitivity reactions have been reported. Signs and symptoms of hypersensitivity reactions may include fever, rash, urticaria, angioedema, hypotension, acute bronchospasm, conjunctivitis, thrombocytopenia, neutropenia, elevated liver transaminases, or flu-like syndrome. Monitor patients for signs/symptoms of hypersensitivity; discontinue therapy if signs/symptoms suggestive of hypersensitivity (eg, fever, lymphadenopathy, eosinophilia, liver abnormalities) occur, even if rash is not evident.
• Pulmonary toxicity: Potentially fatal interstitial lung disease, manifested by pneumonitis, hypersensitivity pneumonitis, eosinophilic pneumonia, pulmonary infiltrates, and organizing pneumonia, has been reported. Permanently discontinue rifampin use and initiate appropriate treatment in patients with signs and symptoms of severe pulmonary toxicity (respiratory failure, pulmonary fibrosis, acute respiratory distress syndrome).
• Superinfection: Prolonged use may result in fungal or bacterial superinfection, including C. difficile-associated diarrhea (CDAD) and pseudomembranous colitis; CDAD has been observed >2 months postantibiotic treatment.
• Thrombotic microangiopathy: Thrombotic microangiopathy, including cases of thrombotic thrombocytopenic purpura or hemolytic uremic syndrome, has been reported (some fatal). Discontinue therapy and clinically evaluate patients with suspected thrombotic microangiopathy.
Disease-related concerns:
• Alcoholism: Use with caution in patients with a history of alcoholism (even if ethanol consumption is discontinued during therapy).
• Diabetes mellitus: Use with caution in patients with diabetes mellitus; management of diabetes may be more difficult in patients taking rifampin.
• Hepatic impairment: Use with caution and close monitoring in patients with hepatic impairment.
• Meningococcal disease: Do not use for treatment of meningococcal disease, only for short-term treatment of asymptomatic carrier states.
• Porphyria: Use with caution in patients with porphyria; exacerbations have been reported due to enzyme-inducing properties.
Other warnings/precautions:
• Compliance: Monitor for compliance in patients on intermittent therapy.
• Contact lenses: Remove soft contact lenses during therapy since permanent staining may occur.
• Discoloration: Teeth (may be permanent), urine, feces, saliva, sweat, and tears may be discolored (yellow, orange, red, or brown).
Substrate of OATP1B1/1B3 (SLCO1B1/1B3), P-glycoprotein/ABCB1 (minor); Note: Assignment of Major/Minor substrate status based on clinically relevant drug interaction potential; Inhibits OATP1B1/1B3 (SLCO1B1/1B3); Induces BCRP/ABCG2, CYP1A2 (weak), CYP2B6 (moderate), CYP2C19 (strong), CYP2C8 (moderate), CYP2C9 (moderate), CYP3A4 (strong), OATP1B1/1B3 (SLCO1B1/1B3), P-glycoprotein/ABCB1, UGT1A1, UGT1A9
Abemaciclib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Abemaciclib. Risk X: Avoid combination
Abiraterone Acetate: CYP3A4 Inducers (Strong) may decrease the serum concentration of Abiraterone Acetate. Management: Avoid whenever possible. If such a combination cannot be avoided, increase abiraterone acetate dosing frequency from once daily to twice daily during concomitant use. Risk D: Consider therapy modification
Abrocitinib: CYP2C19 Inducers (Strong) may decrease the serum concentration of Abrocitinib. Risk X: Avoid combination
Acalabrutinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Acalabrutinib. Management: Avoid co-administration of strong CYP3A inducers in patients taking acalabrutinib. If strong CYP3A inducers cannot be avoided, increase the dose of acalabrutinib to 200 mg twice daily. Risk D: Consider therapy modification
Acetaminophen: RifAMPin may enhance the hepatotoxic effect of Acetaminophen. RifAMPin may decrease the serum concentration of Acetaminophen. Risk C: Monitor therapy
Afatinib: P-glycoprotein/ABCB1 Inducers may decrease the serum concentration of Afatinib. Management: Increase the afatinib dose by 10 mg as tolerated in patients requiring chronic coadministration of P-gp inducers with afatinib. Reduce afatinib dose back to the original afatinib dose 2 to 3 days after discontinuation of the P-gp inducer. Risk D: Consider therapy modification
Agomelatine: RifAMPin may decrease the serum concentration of Agomelatine. Risk C: Monitor therapy
Alfacalcidol: CYP3A4 Inducers (Strong) may decrease the serum concentration of Alfacalcidol. Risk C: Monitor therapy
Alfentanil: CYP3A4 Inducers (Strong) may decrease the serum concentration of Alfentanil. Management: If concomitant use of alfentanil and strong CYP3A4 inducers is necessary, consider dosage increase of alfentanil until stable drug effects are achieved. Monitor patients for signs of opioid withdrawal. Risk D: Consider therapy modification
Aliskiren: P-glycoprotein/ABCB1 Inducers may decrease the serum concentration of Aliskiren. Risk C: Monitor therapy
Alpelisib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Alpelisib. Risk X: Avoid combination
ALPRAZolam: CYP3A4 Inducers (Strong) may decrease the serum concentration of ALPRAZolam. Risk C: Monitor therapy
Amiodarone: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Amiodarone. CYP3A4 Inducers (Strong) may decrease the serum concentration of Amiodarone. Risk C: Monitor therapy
Amitriptyline: RifAMPin may decrease serum concentrations of the active metabolite(s) of Amitriptyline. Specifically, concentrations of nortriptyline may be reduced. RifAMPin may decrease the serum concentration of Amitriptyline. Risk C: Monitor therapy
AmLODIPine: CYP3A4 Inducers (Strong) may decrease the serum concentration of AmLODIPine. Risk C: Monitor therapy
Amodiaquine: CYP2C8 Inducers (Moderate) may decrease the serum concentration of Amodiaquine. Management: Monitor for reduced amodiaquine efficacy if combined with moderate CYP2C8 inducers. Consider increasing artensunate/amodiaquine treatment duration to 5 days if coadministration with enzyme inducing drugs is required. Risk D: Consider therapy modification
Antihepaciviral Combination Products: CYP3A4 Inducers (Strong) may decrease the serum concentration of Antihepaciviral Combination Products. Risk X: Avoid combination
Apixaban: Inducers of CYP3A4 (Strong) and P-glycoprotein may decrease the serum concentration of Apixaban. Risk X: Avoid combination
Apremilast: CYP3A4 Inducers (Strong) may decrease the serum concentration of Apremilast. Risk X: Avoid combination
Aprepitant: CYP3A4 Inducers (Strong) may decrease the serum concentration of Aprepitant. Risk X: Avoid combination
ARIPiprazole: CYP3A4 Inducers (Strong) may decrease the serum concentration of ARIPiprazole. Management: For indications other than major depressive disorder: double the oral aripiprazole dose over 1 to 2 weeks and closely monitor. Avoid use of strong CYP3A4 inducers for more than 14 days with extended-release injectable aripiprazole. Risk D: Consider therapy modification
ARIPiprazole Lauroxil: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of ARIPiprazole Lauroxil. Management: Patients taking the 441 mg dose of aripiprazole lauroxil increase their dose to 662 mg if used with a strong CYP3A4 inducer for more than 14 days. No dose adjustment is necessary for patients using the higher doses of aripiprazole lauroxil. Risk D: Consider therapy modification
Artemether and Lumefantrine: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Artemether and Lumefantrine. Specifically, concentrations of dihydroartemisinin (DHA), the active metabolite of artemether may be decreased. CYP3A4 Inducers (Strong) may decrease the serum concentration of Artemether and Lumefantrine. Risk X: Avoid combination
Artesunate: RifAMPin may decrease serum concentrations of the active metabolite(s) of Artesunate. Risk C: Monitor therapy
Asunaprevir: RifAMPin may decrease the serum concentration of Asunaprevir. This effect is most likely with longer-term coadministration; single-dose rifampin may increase asunaprevir concentrations. RifAMPin may increase the serum concentration of Asunaprevir. This effect is likely following only single-dose or short-term rifampin administration. Longer-term coadministration is likely to result in decreased asunaprevir concentrations. Risk X: Avoid combination
Ataluren: RifAMPin may decrease the serum concentration of Ataluren. Risk C: Monitor therapy
Atazanavir: RifAMPin may decrease the serum concentration of Atazanavir. Risk X: Avoid combination
Atogepant: RifAMPin may decrease the serum concentration of Atogepant. Specifically, atogepant concentrations may be reduced with daily dosing of rifampin. RifAMPin may increase the serum concentration of Atogepant. Specifically, increases in atogepant exposure may occur with single dose of rifampin or at the initiation of rifampin therapy. Management: When administered with single dose rifampin, or at rifampin initiation, the atogepant dose should be 10 mg once daily or 30 mg once daily. When administered with daily dosing of rifampin, the atogepant dose should be 30 mg once daily or 60 mg once daily. Risk D: Consider therapy modification
Atorvastatin: RifAMPin may increase the serum concentration of Atorvastatin. RifAMPin may decrease the serum concentration of Atorvastatin. Management: Administer atorvastatin and rifampin simultaneously if using both. Monitor atorvastatin response closely. Risk D: Consider therapy modification
Atovaquone: May increase the serum concentration of RifAMPin. RifAMPin may decrease the serum concentration of Atovaquone. Risk X: Avoid combination
Avacopan: CYP3A4 Inducers (Strong) may decrease the serum concentration of Avacopan. Risk X: Avoid combination
Avanafil: CYP3A4 Inducers (Strong) may decrease the serum concentration of Avanafil. Risk X: Avoid combination
Avapritinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Avapritinib. Risk X: Avoid combination
Avatrombopag: RifAMPin may decrease the serum concentration of Avatrombopag. Management: For chronic immune thrombocytopenia, increase initial avatrombopag dose to 40 mg daily. No dosage adjustment needed for patients with chronic liver disease-associated thrombocytopenia using altrombopag prior to a procedure. Risk D: Consider therapy modification
Axitinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Axitinib. Risk X: Avoid combination
Barnidipine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Barnidipine. Risk C: Monitor therapy
Bazedoxifene: RifAMPin may decrease the serum concentration of Bazedoxifene. This may lead to loss of efficacy or, if bazedoxifene is combined with estrogen therapy, an increased risk of endometrial hyperplasia. Risk C: Monitor therapy
BCG (Intravesical): Antibiotics may diminish the therapeutic effect of BCG (Intravesical). Risk X: Avoid combination
BCG Vaccine (Immunization): Antibiotics may diminish the therapeutic effect of BCG Vaccine (Immunization). Risk C: Monitor therapy
Bedaquiline: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Bedaquiline. CYP3A4 Inducers (Strong) may decrease the serum concentration of Bedaquiline. Risk X: Avoid combination
Belumosudil: CYP3A4 Inducers (Strong) may decrease the serum concentration of Belumosudil. Management: Increase the dose of belumosudil to 200 mg twice daily when coadministered with strong CYP3A4 inducers. Risk D: Consider therapy modification
Benidipine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Benidipine. Risk C: Monitor therapy
Benperidol: CYP3A4 Inducers (Strong) may decrease the serum concentration of Benperidol. Risk C: Monitor therapy
Benzhydrocodone: CYP3A4 Inducers (Strong) may decrease the serum concentration of Benzhydrocodone. Specifically, the serum concentrations of hydrocodone may be reduced. Risk C: Monitor therapy
Berotralstat: P-glycoprotein/ABCB1 Inducers may decrease the serum concentration of Berotralstat. Risk X: Avoid combination
Betamethasone (Systemic): CYP3A4 Inducers (Strong) may decrease the serum concentration of Betamethasone (Systemic). Risk C: Monitor therapy
Bictegravir: RifAMPin may decrease the serum concentration of Bictegravir. Risk X: Avoid combination
Bisoprolol: CYP3A4 Inducers (Strong) may decrease the serum concentration of Bisoprolol. Risk C: Monitor therapy
Blonanserin: CYP3A4 Inducers (Strong) may decrease the serum concentration of Blonanserin. Risk C: Monitor therapy
Bortezomib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Bortezomib. Risk X: Avoid combination
Bosentan: RifAMPin may decrease the serum concentration of Bosentan. Following the initial week of concurrent rifampin, this effect is most likely. RifAMPin may increase the serum concentration of Bosentan. This effect is most likely to be observed within the initial few days of concurrent therapy (and may be greatest immediately following initiation of the combination). Risk C: Monitor therapy
Bosutinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Bosutinib. Risk X: Avoid combination
Brentuximab Vedotin: CYP3A4 Inducers (Strong) may decrease the serum concentration of Brentuximab Vedotin. Specifically, concentrations of the active monomethyl auristatin E (MMAE) component may be decreased. Risk C: Monitor therapy
Brexpiprazole: CYP3A4 Inducers (Strong) may decrease the serum concentration of Brexpiprazole. Management: If brexpiprazole is used together with a strong CYP3A4 inducer, the brexpiprazole dose should gradually be doubled over the course of 1 to 2 weeks. Decrease brexpiprazole to original dose over 1 to 2 weeks if the strong CYP3A4 inducer is discontinued. Risk D: Consider therapy modification
Brigatinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Brigatinib. Risk X: Avoid combination
Brincidofovir: OATP1B1/1B3 (SLCO1B1/1B3) Inhibitors may increase the serum concentration of Brincidofovir. Management: Consider alternatives to OATP1B/1B3 inhibitors in patients treated with brincidofovir. If coadministration is required, administer OATP1B1/1B3 inhibitors at least 3 hours after brincidofovir and increase monitoring for brincidofovir adverse reactions. Risk D: Consider therapy modification
Brivaracetam: CYP2C19 Inducers (Strong) may decrease the serum concentration of Brivaracetam. Management: Increase the brivaracetam dose by up to 100% (ie, double the dose) if used with rifampin and consider the same dose adjustment if used with other strong CYP2C19 inducers. Monitor for reduced brivaracetam efficacy. Risk D: Consider therapy modification
Bromocriptine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Bromocriptine. Risk C: Monitor therapy
Bromperidol: CYP3A4 Inducers (Strong) may decrease the serum concentration of Bromperidol. Risk C: Monitor therapy
Buprenorphine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Buprenorphine. Risk C: Monitor therapy
BuPROPion: CYP2B6 Inducers (Moderate) may decrease the serum concentration of BuPROPion. Risk C: Monitor therapy
BusPIRone: CYP3A4 Inducers (Strong) may decrease the serum concentration of BusPIRone. Management: Consider alternatives to this combination. If coadministration of these agents is deemed necessary, monitor patients for reduced buspirone effects and increase buspirone doses as needed. Risk D: Consider therapy modification
Cabazitaxel: CYP3A4 Inducers (Strong) may decrease the serum concentration of Cabazitaxel. Risk C: Monitor therapy
Cabotegravir: UGT1A1 Inducers may decrease the serum concentration of Cabotegravir. Risk X: Avoid combination
Cabozantinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Cabozantinib. Management: Avoid use of strong CYP3A4 inducers with cabozantinib if possible. If combined, increase cabozantinib capsules (Cometriq) by 40 mg from previous dose, max 180 mg daily. Increase cabozantinib tablets (Cabometyx) by 20 mg from previous dose, max 80 mg daily Risk D: Consider therapy modification
Calcifediol: CYP3A4 Inducers (Strong) may decrease the serum concentration of Calcifediol. Risk C: Monitor therapy
Calcitriol (Systemic): CYP3A4 Inducers (Strong) may decrease the serum concentration of Calcitriol (Systemic). Risk C: Monitor therapy
Canagliflozin: RifAMPin may decrease the serum concentration of Canagliflozin. Management: Consider increasing canagliflozin dose to 200 mg/day in patients tolerating 100 mg/day. A further increase to 300 mg/day can be considered in patients with an estimated glomerular filtration rate (GFR) of 60 mL/min/1.73 m2 or greater. Risk D: Consider therapy modification
Cannabidiol: CYP2C19 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Cannabidiol. CYP2C19 Inducers (Strong) may decrease the serum concentration of Cannabidiol. Risk C: Monitor therapy
Cannabis: CYP3A4 Inducers (Strong) may decrease the serum concentration of Cannabis. More specifically, tetrahydrocannabinol and cannabidiol serum concentrations may be decreased. Risk C: Monitor therapy
Capmatinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Capmatinib. Risk X: Avoid combination
CarBAMazepine: CYP3A4 Inducers (Strong) may decrease the serum concentration of CarBAMazepine. Risk C: Monitor therapy
Cariprazine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Cariprazine. Risk X: Avoid combination
Carisoprodol: CYP2C19 Inducers (Strong) may increase serum concentrations of the active metabolite(s) of Carisoprodol. CYP2C19 Inducers (Strong) may decrease the serum concentration of Carisoprodol. Risk C: Monitor therapy
Carvedilol: RifAMPin may decrease the serum concentration of Carvedilol. Risk C: Monitor therapy
Caspofungin: RifAMPin may decrease the serum concentration of Caspofungin. Management: Caspofungin prescribing information recommends using a dose of 70 mg daily in adults (or 70 mg/m2, up to a maximum of 70 mg, daily in pediatric patients) who are also receiving rifampin. Risk D: Consider therapy modification
CeFAZolin: May enhance the adverse/toxic effect of RifAMPin. Specifically, the risk for bleeding may be increased. Management: Avoid concomitant use of rifampin with cefazolin when possible. If combined, closely monitor prothrombin time or other coagulation tests and administer vitamin K as needed. Risk D: Consider therapy modification
Celecoxib: CYP2C9 Inducers (Moderate) may decrease the serum concentration of Celecoxib. Risk C: Monitor therapy
Celiprolol: P-glycoprotein/ABCB1 Inducers may decrease the serum concentration of Celiprolol. Risk C: Monitor therapy
Cephalosporins (N-methylthiotetrazole [NMTT] Side Chain Containing): May enhance the adverse/toxic effect of RifAMPin. Specifically, the risk for bleeding may be increased. Management: Avoid concomitant use of rifampin with cephalosporins that contain an N-methylthiotetrazole (NMTT) side chain when possible. If combined, closely monitor prothrombin time or other coagulation tests and administer vitamin K as needed. Risk D: Consider therapy modification
Ceritinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Ceritinib. Risk X: Avoid combination
Chloramphenicol (Systemic): RifAMPin may increase the metabolism of Chloramphenicol (Systemic). Risk C: Monitor therapy
ChlorproPAMIDE: CYP3A4 Inducers (Strong) may decrease the serum concentration of ChlorproPAMIDE. Risk C: Monitor therapy
Cholera Vaccine: Antibiotics may diminish the therapeutic effect of Cholera Vaccine. Management: Avoid cholera vaccine in patients receiving systemic antibiotics, and within 14 days following the use of oral or parenteral antibiotics. Risk X: Avoid combination
Cilnidipine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Cilnidipine. Risk C: Monitor therapy
Citalopram: CYP3A4 Inducers (Strong) may decrease the serum concentration of Citalopram. Risk C: Monitor therapy
Cladribine: BCRP/ABCG2 Inducers may decrease the serum concentration of Cladribine. Risk C: Monitor therapy
Cladribine: P-glycoprotein/ABCB1 Inducers may decrease the serum concentration of Cladribine. Risk C: Monitor therapy
Clarithromycin: CYP3A4 Inducers (Strong) may increase serum concentrations of the active metabolite(s) of Clarithromycin. CYP3A4 Inducers (Strong) may decrease the serum concentration of Clarithromycin. Management: Consider alternative antimicrobial therapy for patients receiving a CYP3A4 inducer. Drugs that enhance the metabolism of clarithromycin into 14-hydroxyclarithromycin may alter the clinical activity of clarithromycin and may impair clarithromycin efficacy. Risk D: Consider therapy modification
ClonazePAM: CYP3A4 Inducers (Strong) may decrease the serum concentration of ClonazePAM. Risk C: Monitor therapy
Clopidogrel: CYP2C19 Inducers (Strong) may increase serum concentrations of the active metabolite(s) of Clopidogrel. Management: Consider alternatives to this combination when possible. If combined, monitor for increased clopidogrel effects and toxicities (eg, bleeding) if clopidogrel is combined with a strong CYP2C19 inducer. Risk D: Consider therapy modification
CloZAPine: CYP3A4 Inducers (Strong) may decrease the serum concentration of CloZAPine. Management: Avoid use with strong CYP3A4 inducers when possible. If combined, monitor patients closely and consider clozapine dose increases. Clozapine dose reduction and further monitoring may be required when strong CYP3A4 inducers are discontinued. Risk D: Consider therapy modification
Cobicistat: RifAMPin may decrease the serum concentration of Cobicistat. Risk X: Avoid combination
Cobimetinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Cobimetinib. Risk X: Avoid combination
Codeine: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Codeine. Risk C: Monitor therapy
Copanlisib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Copanlisib. Risk X: Avoid combination
Crizotinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Crizotinib. Risk X: Avoid combination
Cyclophosphamide: CYP2B6 Inducers (Moderate) may increase serum concentrations of the active metabolite(s) of Cyclophosphamide. Risk C: Monitor therapy
CycloSPORINE (Systemic): CYP3A4 Inducers (Strong) may decrease the serum concentration of CycloSPORINE (Systemic). Management: Monitor closely for reduced cyclosporine concentrations when combined with strong CYP3A4 inducers. Cyclosporine dose increases will likely be required to maintain adequate serum concentrations. Risk D: Consider therapy modification
Cyproterone: CYP3A4 Inducers (Strong) may decrease the serum concentration of Cyproterone. Risk C: Monitor therapy
Dabigatran Etexilate: P-glycoprotein/ABCB1 Inducers may decrease the serum concentration of Dabigatran Etexilate. Management: Avoid concurrent use of dabigatran with P-glycoprotein inducers whenever possible. Risk X: Avoid combination
Daclatasvir: CYP3A4 Inducers (Strong) may decrease the serum concentration of Daclatasvir. Risk X: Avoid combination
Dapsone (Systemic): May enhance the adverse/toxic effect of CYP3A4 Inducers (Strong). CYP3A4 Inducers (Strong) may decrease the serum concentration of Dapsone (Systemic). Risk C: Monitor therapy
Daridorexant: CYP3A4 Inducers (Strong) may decrease the serum concentration of Daridorexant. Risk X: Avoid combination
Darolutamide: Inducers of CYP3A4 (Strong) and P-glycoprotein may decrease the serum concentration of Darolutamide. Risk X: Avoid combination
Darunavir: RifAMPin may decrease the serum concentration of Darunavir. Risk X: Avoid combination
Dasabuvir: CYP3A4 Inducers (Strong) may decrease the serum concentration of Dasabuvir. Risk X: Avoid combination
Dasatinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Dasatinib. Management: Avoid concurrent use of dasatinib with strong CYP3A4 inducers when possible. If such a combination cannot be avoided, consider increasing dasatinib dose and monitor clinical response and toxicity closely. Risk D: Consider therapy modification
Deferasirox: RifAMPin may decrease the serum concentration of Deferasirox. Management: Avoid combination when possible; if the combination must be used, consider a 50% increase in initial deferasirox dose, with monitoring of serum ferritin concentrations and clinical responses to guide further dosing. Risk D: Consider therapy modification
Deflazacort: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Deflazacort. Risk X: Avoid combination
Delamanid: CYP3A4 Inducers (Strong) may decrease the serum concentration of Delamanid. Risk X: Avoid combination
Delavirdine: RifAMPin may decrease the serum concentration of Delavirdine. Risk X: Avoid combination
DexAMETHasone (Systemic): CYP3A4 Inducers (Strong) may decrease the serum concentration of DexAMETHasone (Systemic). Management: Consider dexamethasone dose increases in patients receiving strong CYP3A4 inducers and monitor closely for reduced dexamethasone efficacy. Consider avoiding this combination when treating life threatening conditions (ie, multiple myeloma). Risk D: Consider therapy modification
Dexlansoprazole: CYP2C19 Inducers (Strong) may decrease the serum concentration of Dexlansoprazole. Risk X: Avoid combination
DiazePAM: CYP3A4 Inducers (Strong) may decrease the serum concentration of DiazePAM. Risk C: Monitor therapy
Diclofenac (Systemic): CYP2C9 Inducers (Moderate) may decrease the serum concentration of Diclofenac (Systemic). Risk C: Monitor therapy
Digoxin: P-glycoprotein/ABCB1 Inducers may decrease the serum concentration of Digoxin. Risk C: Monitor therapy
DilTIAZem: CYP3A4 Inducers (Strong) may decrease the serum concentration of DilTIAZem. Management: Consider alternatives to this combination when possible. If combined, monitor for decreased diltiazem efficacy. Risk D: Consider therapy modification
Disopyramide: CYP3A4 Inducers (Strong) may decrease the serum concentration of Disopyramide. Risk C: Monitor therapy
Dolutegravir: RifAMPin may decrease the serum concentration of Dolutegravir. Management: Increase dolutegravir to 50 mg twice/day in adults. Increase weight based dose to twice daily in pediatric patients. See interaction monograph for details. Seek alternative to rifampin if suspected INSTI resistance. Risk D: Consider therapy modification
Domperidone: CYP3A4 Inducers (Strong) may decrease the serum concentration of Domperidone. Risk C: Monitor therapy
Doravirine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Doravirine. Risk X: Avoid combination
Doxercalciferol: CYP3A4 Inducers (Strong) may increase serum concentrations of the active metabolite(s) of Doxercalciferol. Risk C: Monitor therapy
DOXOrubicin (Conventional): CYP3A4 Inducers (Strong) may decrease the serum concentration of DOXOrubicin (Conventional). Risk X: Avoid combination
DOXOrubicin (Conventional): P-glycoprotein/ABCB1 Inducers may decrease the serum concentration of DOXOrubicin (Conventional). Risk X: Avoid combination
Doxycycline: RifAMPin may decrease the serum concentration of Doxycycline. Risk C: Monitor therapy
Dronabinol: CYP3A4 Inducers (Strong) may decrease the serum concentration of Dronabinol. Risk C: Monitor therapy
Dronedarone: CYP3A4 Inducers (Strong) may decrease the serum concentration of Dronedarone. Risk X: Avoid combination
Duvelisib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Duvelisib. Risk X: Avoid combination
Dydrogesterone: CYP3A4 Inducers (Strong) may decrease the serum concentration of Dydrogesterone. Risk C: Monitor therapy
Ebastine: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Ebastine. CYP3A4 Inducers (Strong) may decrease the serum concentration of Ebastine. Risk C: Monitor therapy
Edoxaban: RifAMPin may decrease the serum concentration of Edoxaban. Risk X: Avoid combination
Efavirenz: RifAMPin may decrease the serum concentration of Efavirenz. Efavirenz may decrease the serum concentration of RifAMPin. Management: Monitor for reduced response to efavirenz and rifampin. Guidelines suggest no efavirenz dose adjustments are required when combined, while labeling recommends an efavirenz dose increase to 800 mg daily in adults weighing more than 50 kg. Risk C: Monitor therapy
Elagolix: RifAMPin may increase the serum concentration of Elagolix. Management: Use of the elagolix 200 mg twice daily dose with rifampin is not recommended. Limit combined use of the elagolix 150 mg once daily dose with rifampin to a maximum of 6 months. Risk D: Consider therapy modification
Elagolix, Estradiol, and Norethindrone: May increase the serum concentration of RifAMPin. Specifically, rifampin may increase elagolix concentrations and decrease estradiol and norethindrone concentrations. Risk X: Avoid combination
Elbasvir and Grazoprevir: RifAMPin may increase the serum concentration of Elbasvir and Grazoprevir. RifAMPin may decrease the serum concentration of Elbasvir and Grazoprevir. Risk X: Avoid combination
Elexacaftor, Tezacaftor, and Ivacaftor: CYP3A4 Inducers (Strong) may decrease the serum concentration of Elexacaftor, Tezacaftor, and Ivacaftor. Risk X: Avoid combination
Eliglustat: CYP3A4 Inducers (Strong) may decrease the serum concentration of Eliglustat. Risk X: Avoid combination
Eluxadoline: OATP1B1/1B3 (SLCO1B1/1B3) Inhibitors may increase the serum concentration of Eluxadoline. Management: Decrease the eluxadoline dose to 75 mg twice daily if combined with OATP1B1/1B3 inhibitors and monitor patients for increased eluxadoline effects/toxicities. Risk D: Consider therapy modification
Elvitegravir: RifAMPin may decrease the serum concentration of Elvitegravir. Risk X: Avoid combination
Encorafenib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Encorafenib. Risk X: Avoid combination
Enfortumab Vedotin: CYP3A4 Inducers (Strong) may decrease the serum concentration of Enfortumab Vedotin. Specifically, concentrations of the active monomethyl auristatin E (MMAE) component may be decreased. Risk C: Monitor therapy
Entrectinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Entrectinib. Risk X: Avoid combination
Enzalutamide: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Enzalutamide. CYP3A4 Inducers (Strong) may decrease the serum concentration of Enzalutamide. Management: Consider using an alternative agent that has no or minimal CYP3A4 induction potential when possible. If this combination cannot be avoided, increase the dose of enzalutamide from 160 mg daily to 240 mg daily. Risk D: Consider therapy modification
Eplerenone: CYP3A4 Inducers (Strong) may decrease the serum concentration of Eplerenone. Risk C: Monitor therapy
Eravacycline: CYP3A4 Inducers (Strong) may decrease the serum concentration of Eravacycline. Management: Increase the eravacycline dose to 1.5 mg/kg every 12 hours when combined with strong CYP3A4 inducers. Risk D: Consider therapy modification
Erdafitinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Erdafitinib. Risk X: Avoid combination
Erlotinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Erlotinib. Management: Avoid the combination of erlotinib and strong CYP3A4 inducers whenever possible. If this combination must be used, increase erlotinib dose by 50 mg increments every 2 weeks as tolerated, to a maximum of 450 mg/day. Risk D: Consider therapy modification
Escitalopram: CYP3A4 Inducers (Strong) may decrease the serum concentration of Escitalopram. Risk C: Monitor therapy
Esomeprazole: CYP2C19 Inducers (Strong) may decrease the serum concentration of Esomeprazole. Risk X: Avoid combination
Estazolam: CYP3A4 Inducers (Strong) may decrease the serum concentration of Estazolam. Risk C: Monitor therapy
Estrogen Derivatives: CYP3A4 Inducers (Strong) may decrease the serum concentration of Estrogen Derivatives. Risk C: Monitor therapy
Eszopiclone: CYP3A4 Inducers (Strong) may decrease the serum concentration of Eszopiclone. Risk C: Monitor therapy
Ethosuximide: CYP3A4 Inducers (Strong) may decrease the serum concentration of Ethosuximide. Risk C: Monitor therapy
Etizolam: CYP3A4 Inducers (Strong) may decrease the serum concentration of Etizolam. Risk C: Monitor therapy
Etoposide: CYP3A4 Inducers (Strong) may decrease the serum concentration of Etoposide. Management: When possible, seek alternatives to strong CYP3A4-inducing medications in patients receiving etoposide. If combined, monitor patients closely for diminished etoposide response and need for etoposide dose increases. Risk D: Consider therapy modification
Etoposide Phosphate: CYP3A4 Inducers (Strong) may decrease the serum concentration of Etoposide Phosphate. Management: When possible, seek alternatives to strong CYP3A4-inducing medications in patients receiving etoposide phosphate. If these combinations cannot be avoided, monitor patients closely for diminished etoposide phosphate response. Risk D: Consider therapy modification
Etoricoxib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Etoricoxib. Risk C: Monitor therapy
Etravirine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Etravirine. Risk X: Avoid combination
Everolimus: Inducers of CYP3A4 (Strong) and P-glycoprotein may decrease the serum concentration of Everolimus. Management: Afinitor: Double the everolimus daily dose, using increments of 5 mg or less, with careful monitoring; multiple increments may be necessary. Zortress: Avoid if possible and monitor for decreased everolimus concentrations if combined. Risk D: Consider therapy modification
Evogliptin: CYP3A4 Inducers (Strong) may decrease the serum concentration of Evogliptin. Risk C: Monitor therapy
Exemestane: CYP3A4 Inducers (Strong) may decrease the serum concentration of Exemestane. Management: Increase the exemestane dose to 50 mg once daily in patients receiving concurrent strong CYP3A4 inducers. Monitor patients closely for evidence of toxicity or inadequate clinical response. Risk D: Consider therapy modification
Fedratinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Fedratinib. Risk X: Avoid combination
Felbamate: CYP3A4 Inducers (Strong) may decrease the serum concentration of Felbamate. Risk C: Monitor therapy
Felodipine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Felodipine. Management: Consider alternatives to this combination when possible. If combined, monitor for reduced felodipine efficacy and the need for felodipine dose increases. Risk D: Consider therapy modification
Fenfluramine: RifAMPin may decrease the serum concentration of Fenfluramine. Management: Consider increasing the fenfluramine dose when used together with rifampin, but do not exceed the fenfluramine maximum daily dosage [0.35 mg/kg twice daily (26 mg/day)]. Risk C: Monitor therapy
FentaNYL: CYP3A4 Inducers (Strong) may decrease the serum concentration of FentaNYL. Risk C: Monitor therapy
Fesoterodine: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Fesoterodine. Risk C: Monitor therapy
Fexinidazole: CYP3A4 Inducers (Strong) may increase serum concentrations of the active metabolite(s) of Fexinidazole. Risk X: Avoid combination
Fexofenadine: RifAMPin may decrease the serum concentration of Fexofenadine. RifAMPin may increase the serum concentration of Fexofenadine. Risk C: Monitor therapy
Fimasartan: RifAMPin may increase the serum concentration of Fimasartan. Risk X: Avoid combination
Finerenone: CYP3A4 Inducers (Strong) may decrease the serum concentration of Finerenone. Risk X: Avoid combination
Flibanserin: CYP3A4 Inducers (Strong) may decrease the serum concentration of Flibanserin. Risk X: Avoid combination
Fluconazole: RifAMPin may decrease the serum concentration of Fluconazole. Fluconazole may increase the serum concentration of RifAMPin. Management: Consider increasing the dose of fluconazole when used concurrently with rifampin. When combined, monitor for both reduced clinical efficacy of fluconazole and increased rifampin toxicities. Risk D: Consider therapy modification
Fluvastatin: RifAMPin may decrease the serum concentration of Fluvastatin. Specifically, this occurs with prolonged coadministration. RifAMPin may increase the serum concentration of Fluvastatin. Specifically, this occurs upon rifampin initiation. Risk C: Monitor therapy
Fosamprenavir: RifAMPin may decrease the serum concentration of Fosamprenavir. Specifically, concentrations of amprenavir (active metabolite) may be decreased. Risk X: Avoid combination
Fosaprepitant: CYP3A4 Inducers (Strong) may decrease the serum concentration of Fosaprepitant. Specifically, CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite aprepitant. Risk X: Avoid combination
Fosnetupitant: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Fosnetupitant. Risk X: Avoid combination
Fosphenytoin-Phenytoin: CYP2C19 Inducers (Strong) may decrease the serum concentration of Fosphenytoin-Phenytoin. Risk C: Monitor therapy
Fostamatinib: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Fostamatinib. Risk X: Avoid combination
Fostemsavir: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Fostemsavir. Risk X: Avoid combination
Gefitinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Gefitinib. Management: In the absence of severe adverse reactions, increase the gefitinib dose to 500 mg daily in patients receiving strong CYP3A4 inducers; resume 250 mg dose 7 days after discontinuation of the strong inducer. Carefully monitor clinical response. Risk D: Consider therapy modification
Gemigliptin: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Gemigliptin. CYP3A4 Inducers (Strong) may decrease the serum concentration of Gemigliptin. Risk X: Avoid combination
Gestrinone: RifAMPin may decrease the serum concentration of Gestrinone. Risk C: Monitor therapy
Gilteritinib: Inducers of CYP3A4 (Strong) and P-glycoprotein may decrease the serum concentration of Gilteritinib. Risk X: Avoid combination
Glasdegib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Glasdegib. Risk X: Avoid combination
Glecaprevir and Pibrentasvir: RifAMPin may decrease the serum concentration of Glecaprevir and Pibrentasvir. RifAMPin may increase the serum concentration of Glecaprevir and Pibrentasvir. Specifically, a single dose of rifampin may increase glecaprevir/pibrentasvir concentrations, while chronic daily use of rifampin may decrease glecaprevir/pibrentasvir concentrations. Risk X: Avoid combination
GuanFACINE: CYP3A4 Inducers (Strong) may decrease the serum concentration of GuanFACINE. Management: Increase extended-release guanfacine dose by up to double when initiating guanfacine in patients taking CYP3A4 inducers or if initiating a CYP3A4 inducer in a patient already taking extended-release guanfacine. Monitor for reduced guanfacine efficacy. Risk D: Consider therapy modification
Haloperidol: CYP3A4 Inducers (Strong) may decrease the serum concentration of Haloperidol. Risk C: Monitor therapy
Hormonal Contraceptives: CYP3A4 Inducers (Strong) may decrease the serum concentration of Hormonal Contraceptives. Management: Advise patients to use an alternative method of contraception or a back-up method during coadministration, and to continue back-up contraception for 28 days after discontinuing a strong CYP3A4 inducer to ensure contraceptive reliability. Risk D: Consider therapy modification
HYDROcodone: CYP3A4 Inducers (Strong) may decrease the serum concentration of HYDROcodone. Risk C: Monitor therapy
Hydrocortisone (Systemic): CYP3A4 Inducers (Strong) may decrease the serum concentration of Hydrocortisone (Systemic). Risk C: Monitor therapy
Ibrexafungerp: CYP3A4 Inducers (Strong) may decrease the serum concentration of Ibrexafungerp. Risk X: Avoid combination
Ibrutinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Ibrutinib. Risk X: Avoid combination
Idelalisib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Idelalisib. Risk X: Avoid combination
Ifosfamide: CYP3A4 Inducers (Strong) may increase serum concentrations of the active metabolite(s) of Ifosfamide. CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Ifosfamide. Risk C: Monitor therapy
Imatinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Imatinib. Management: Avoid use of imatinib and strong CYP3A4 inducers when possible. If such a combination must be used, increase imatinib dose by at least 50% and monitor the patient's clinical response closely. Doses up to 1200 mg/day (600 mg twice daily) have been used. Risk D: Consider therapy modification
Immune Checkpoint Inhibitors: Antibiotics may diminish the therapeutic effect of Immune Checkpoint Inhibitors. Risk C: Monitor therapy
Indinavir: RifAMPin may decrease the serum concentration of Indinavir. Risk X: Avoid combination
Infigratinib: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Infigratinib. CYP3A4 Inducers (Strong) may decrease the serum concentration of Infigratinib. Risk X: Avoid combination
Irinotecan Products: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Irinotecan Products. Specifically, serum concentrations of SN-38 may be reduced. CYP3A4 Inducers (Strong) may decrease the serum concentration of Irinotecan Products. Management: Avoid administration of strong CYP3A4 inducers during irinotecan treatment, and substitute non-CYP3A4 inducing agents at least 2 weeks prior to irinotecan initiation, whenever possible. If combined, monitor for reduced irinotecan efficacy. Risk D: Consider therapy modification
Isavuconazonium Sulfate: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Isavuconazonium Sulfate. Specifically, CYP3A4 Inducers (Strong) may decrease isavuconazole serum concentrations. Risk X: Avoid combination
Isoniazid: May enhance the hepatotoxic effect of RifAMPin. Risk C: Monitor therapy
Isradipine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Isradipine. Risk C: Monitor therapy
Istradefylline: CYP3A4 Inducers (Strong) may decrease the serum concentration of Istradefylline. Risk X: Avoid combination
Itraconazole: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Itraconazole. CYP3A4 Inducers (Strong) may decrease the serum concentration of Itraconazole. Risk X: Avoid combination
Ivabradine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Ivabradine. Risk X: Avoid combination
Ivacaftor: CYP3A4 Inducers (Strong) may decrease the serum concentration of Ivacaftor. Risk X: Avoid combination
Ivosidenib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Ivosidenib. Risk X: Avoid combination
Ixabepilone: CYP3A4 Inducers (Strong) may decrease the serum concentration of Ixabepilone. Management: Avoid this combination whenever possible. If this combination must be used, a gradual increase in ixabepilone dose from 40 mg/m2 to 60 mg/m2 (given as a 4-hour infusion), as tolerated, should be considered. Risk D: Consider therapy modification
Ixazomib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Ixazomib. Risk X: Avoid combination
Ketamine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Ketamine. Risk C: Monitor therapy
Ketoconazole (Systemic): CYP3A4 Inducers (Strong) may decrease the serum concentration of Ketoconazole (Systemic). Management: The use of ketoconazole concurrently with or within 2 weeks of a strong CYP3A4 inducer is not recommended. If such a combination cannot be avoided, monitor patients closely for evidence of diminished clinical response to ketoconazole. Risk D: Consider therapy modification
Lacidipine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Lacidipine. Risk C: Monitor therapy
Lactobacillus and Estriol: Antibiotics may diminish the therapeutic effect of Lactobacillus and Estriol. Risk C: Monitor therapy
LamoTRIgine: RifAMPin may decrease the serum concentration of LamoTRIgine. Management: For patients taking rifampin without valproate, lamotrigine dose adjustments are recommended for lamotrigine initiation. Recommendations vary based on lamotrigine indication and age. See full interact monograph for details. Risk D: Consider therapy modification
Lansoprazole: CYP2C19 Inducers (Strong) may decrease the serum concentration of Lansoprazole. Risk X: Avoid combination
Lapatinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Lapatinib. Management: If concomitant use cannot be avoided, titrate lapatinib gradually from 1,250 mg/day up to 4,500 mg/day (HER2 positive metastatic breast cancer) or 1,500 mg/day up to 5,500 mg/day (hormone receptor/HER2 positive breast cancer) as tolerated. Risk D: Consider therapy modification
Larotrectinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Larotrectinib. Management: Avoid use of strong CYP3A4 inducers with larotrectinib. If this combination cannot be avoided, double the larotrectinib dose. Reduced to previous dose after stopping the inducer after a period of 3 to 5 times the inducer's half-life. Risk D: Consider therapy modification
Ledipasvir: P-glycoprotein/ABCB1 Inducers may decrease the serum concentration of Ledipasvir. Risk X: Avoid combination
Lefamulin: CYP3A4 Inducers (Strong) may decrease the serum concentration of Lefamulin. Management: Avoid concomitant use of lefamulin with strong CYP3A4 inducers unless the benefits outweigh the risks. Risk D: Consider therapy modification
Lefamulin: P-glycoprotein/ABCB1 Inducers may decrease the serum concentration of Lefamulin. Management: Avoid concomitant use of lefamulin with P-glycoprotein/ABCB1 inducers unless the benefits outweigh the risks. Risk D: Consider therapy modification
Lefamulin (Intravenous): CYP3A4 Inducers (Strong) may decrease the serum concentration of Lefamulin (Intravenous). Management: Avoid concomitant use of lefamulin intravenous infusion with strong CYP3A4 inducers unless the benefits outweigh the risks. Risk D: Consider therapy modification
Lefamulin (Intravenous): P-glycoprotein/ABCB1 Inducers may decrease the serum concentration of Lefamulin (Intravenous). Management: Avoid concomitant use of lefamulin (intravenous) with P-glycoprotein/ABCB1 inducers unless the benefits outweigh the risks. Risk D: Consider therapy modification
Leflunomide: RifAMPin may increase serum concentrations of the active metabolite(s) of Leflunomide. Risk C: Monitor therapy
Lemborexant: CYP3A4 Inducers (Strong) may decrease the serum concentration of Lemborexant. Risk X: Avoid combination
Lercanidipine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Lercanidipine. Risk C: Monitor therapy
Lesinurad: CYP2C9 Inducers (Moderate) may decrease the serum concentration of Lesinurad. Risk C: Monitor therapy
Letermovir: P-glycoprotein/ABCB1 Inducers may decrease the serum concentration of Letermovir. Risk X: Avoid combination
Letermovir: May increase the serum concentration of UGT1A1 Inducers. Risk X: Avoid combination
Leuprolide and Norethindrone: CYP3A4 Inducers (Strong) may decrease the serum concentration of Leuprolide and Norethindrone. Specifically, norethindrone concentrations may be decreased. Risk C: Monitor therapy
Levamlodipine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Levamlodipine. Risk C: Monitor therapy
Levoketoconazole: CYP3A4 Inducers (Strong) may decrease the serum concentration of Levoketoconazole. Risk X: Avoid combination
Levomethadone: CYP3A4 Inducers (Strong) may decrease the serum concentration of Levomethadone. Risk C: Monitor therapy
Levonorgestrel (IUD): CYP3A4 Inducers (Strong) may diminish the therapeutic effect of Levonorgestrel (IUD). CYP3A4 Inducers (Strong) may decrease the serum concentration of Levonorgestrel (IUD). Risk C: Monitor therapy
Lidocaine (Systemic): CYP3A4 Inducers (Strong) may decrease the serum concentration of Lidocaine (Systemic). Risk C: Monitor therapy
LinaGLIPtin: CYP3A4 Inducers (Strong) may decrease the serum concentration of LinaGLIPtin. Management: Strongly consider using an alternative to any strong CYP3A4 inducer in patients who are being treated with linagliptin. If this combination is used, monitor patients closely for evidence of reduced linagliptin effectiveness. Risk D: Consider therapy modification
LinaGLIPtin: P-glycoprotein/ABCB1 Inducers may decrease the serum concentration of LinaGLIPtin. Management: Strongly consider using an alternative to any P-glycoprotein inducer in patients who are being treated with linagliptin. If this combination is used, monitor patients closely for evidence of reduced linagliptin effectiveness. Risk D: Consider therapy modification
Lonafarnib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Lonafarnib. Risk X: Avoid combination
Lopinavir: RifAMPin may enhance the adverse/toxic effect of Lopinavir. Specifically, the risk of hepatocellular toxicity may be increased. RifAMPin may decrease the serum concentration of Lopinavir. Risk X: Avoid combination
Lorlatinib: CYP3A4 Inducers (Strong) may enhance the hepatotoxic effect of Lorlatinib. CYP3A4 Inducers (Strong) may decrease the serum concentration of Lorlatinib. Risk X: Avoid combination
Lornoxicam: CYP2C9 Inducers (Moderate) may decrease the serum concentration of Lornoxicam. Risk C: Monitor therapy
Lovastatin: RifAMPin may decrease the serum concentration of Lovastatin. Risk C: Monitor therapy
Lumacaftor and Ivacaftor: CYP3A4 Inducers (Strong) may decrease the serum concentration of Lumacaftor and Ivacaftor. Specifically, the serum concentration of ivacaftor may be decreased. Risk X: Avoid combination
Lumateperone: CYP3A4 Inducers (Strong) may decrease the serum concentration of Lumateperone. Risk X: Avoid combination
Lurasidone: CYP3A4 Inducers (Strong) may decrease the serum concentration of Lurasidone. Risk X: Avoid combination
Lurbinectedin: CYP3A4 Inducers (Strong) may decrease the serum concentration of Lurbinectedin. Risk X: Avoid combination
Macimorelin: CYP3A4 Inducers (Strong) may decrease the serum concentration of Macimorelin. Risk X: Avoid combination
Macitentan: CYP3A4 Inducers (Strong) may decrease the serum concentration of Macitentan. Risk X: Avoid combination
Manidipine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Manidipine. Management: Consider avoiding concomitant use of manidipine and strong CYP3A4 inducers. If combined, monitor closely for decreased manidipine effects and loss of efficacy. Increased manidipine doses may be required. Risk D: Consider therapy modification
Maraviroc: CYP3A4 Inducers (Strong) may decrease the serum concentration of Maraviroc. Management: Increase maraviroc adult dose to 600 mg twice/day, but only if not receiving a strong CYP3A4 inhibitor. Not recommended for pediatric patients not also receiving a strong CYP3A4 inhibitor. Contraindicated in patients with CrCl less than 30 mL/min. Risk D: Consider therapy modification
Maribavir: CYP3A4 Inducers (Strong) may decrease the serum concentration of Maribavir. Risk X: Avoid combination
Mefloquine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Mefloquine. Risk C: Monitor therapy
Meperidine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Meperidine. Risk C: Monitor therapy
Methadone: CYP3A4 Inducers (Strong) may decrease the serum concentration of Methadone. Risk C: Monitor therapy
Methylergonovine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Methylergonovine. Risk C: Monitor therapy
MethylPREDNISolone: CYP3A4 Inducers (Strong) may decrease the serum concentration of MethylPREDNISolone. Management: Consider methylprednisolone dose increases in patients receiving strong CYP3A4 inducers and monitor closely for reduced steroid efficacy. Risk D: Consider therapy modification
Metoprolol: RifAMPin may decrease the serum concentration of Metoprolol. Risk C: Monitor therapy
Mexiletine: RifAMPin may decrease the serum concentration of Mexiletine. Risk C: Monitor therapy
Mianserin: CYP3A4 Inducers (Strong) may decrease the serum concentration of Mianserin. Risk C: Monitor therapy
Midazolam: CYP3A4 Inducers (Strong) may decrease the serum concentration of Midazolam. Risk C: Monitor therapy
Midostaurin: CYP3A4 Inducers (Strong) may decrease the serum concentration of Midostaurin. Risk X: Avoid combination
MiFEPRIStone: CYP3A4 Inducers (Strong) may decrease the serum concentration of MiFEPRIStone. Risk X: Avoid combination
Mirabegron: CYP3A4 Inducers (Strong) may decrease the serum concentration of Mirabegron. Risk C: Monitor therapy
Mirodenafil: CYP3A4 Inducers (Strong) may decrease the serum concentration of Mirodenafil. Management: Consider avoiding the concomitant use of mirodenafil and strong CYP3A4 inducers. If combined, monitor for decreased mirodenafil effects. Mirodenafil dose increases may be required to achieve desired effects. Risk D: Consider therapy modification
Mirtazapine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Mirtazapine. Risk C: Monitor therapy
Mitapivat: CYP3A4 Inducers (Strong) may decrease the serum concentration of Mitapivat. Risk X: Avoid combination
Mobocertinib: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Mobocertinib. CYP3A4 Inducers (Strong) may decrease the serum concentration of Mobocertinib. Risk X: Avoid combination
Morphine (Systemic): RifAMPin may decrease the serum concentration of Morphine (Systemic). Risk C: Monitor therapy
Mycophenolate: RifAMPin may decrease serum concentrations of the active metabolite(s) of Mycophenolate. Specifically, concentrations of mycophenolic acid (MPA) may be decreased. Management: Avoid concurrent use of rifampin and mycophenolate when possible. If used together, closely monitor mycophenolic acid levels and clinical response. Mycophenolate doses may need to be increased. Risk D: Consider therapy modification
Naldemedine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Naldemedine. Risk X: Avoid combination
Naloxegol: CYP3A4 Inducers (Strong) may decrease the serum concentration of Naloxegol. Risk X: Avoid combination
Nateglinide: CYP3A4 Inducers (Strong) may decrease the serum concentration of Nateglinide. Risk C: Monitor therapy
Nelfinavir: RifAMPin may decrease the serum concentration of Nelfinavir. Risk X: Avoid combination
Neratinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Neratinib. Risk X: Avoid combination
Netupitant: CYP3A4 Inducers (Strong) may decrease the serum concentration of Netupitant. Risk X: Avoid combination
Nevirapine: RifAMPin may decrease the serum concentration of Nevirapine. Risk X: Avoid combination
NiCARdipine: CYP3A4 Inducers (Strong) may decrease the serum concentration of NiCARdipine. Risk C: Monitor therapy
NIFEdipine: CYP3A4 Inducers (Strong) may decrease the serum concentration of NIFEdipine. Management: Avoid coadministration of nifedipine with strong CYP3A4 inducers when possible and if combined, monitor patients closely for clinical signs of diminished nifedipine response. Risk D: Consider therapy modification
Nilotinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Nilotinib. Risk X: Avoid combination
Nilvadipine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Nilvadipine. Risk C: Monitor therapy
NiMODipine: CYP3A4 Inducers (Strong) may decrease the serum concentration of NiMODipine. Risk X: Avoid combination
Nintedanib: Inducers of CYP3A4 (Strong) and P-glycoprotein may decrease the serum concentration of Nintedanib. Risk X: Avoid combination
Nirmatrelvir: CYP3A4 Inducers (Strong) may decrease the serum concentration of Nirmatrelvir. Risk X: Avoid combination
Nisoldipine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Nisoldipine. Risk X: Avoid combination
Nitrazepam: RifAMPin may decrease the serum concentration of Nitrazepam. Management: Monitor closely for reduced effects of nitrazepam. When possible, consider alternatives to one of these drugs, or increases in initial nitrazepam doses. Risk D: Consider therapy modification
Nitrendipine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Nitrendipine. Risk C: Monitor therapy
Nortriptyline: RifAMPin may decrease the serum concentration of Nortriptyline. Risk C: Monitor therapy
OLANZapine: RifAMPin may decrease the serum concentration of OLANZapine. Risk C: Monitor therapy
Olaparib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Olaparib. Risk X: Avoid combination
Oliceridine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Oliceridine. Risk C: Monitor therapy
Olmutinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Olmutinib. Risk C: Monitor therapy
Omeprazole: CYP2C19 Inducers (Strong) may decrease the serum concentration of Omeprazole. Risk X: Avoid combination
Ondansetron: CYP3A4 Inducers (Strong) may decrease the serum concentration of Ondansetron. Risk C: Monitor therapy
Osilodrostat: CYP3A4 Inducers (Strong) may decrease the serum concentration of Osilodrostat. Risk C: Monitor therapy
Osimertinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Osimertinib. Management: Avoid coadministration of osimertinib and strong CYP3A4 inducers if possible. If coadministration is unavoidable, increase osimertinib to 160 mg daily. Reduce osimertinib to 80 mg daily 3 weeks after discontinuation of the strong CYP3A4 inducer. Risk D: Consider therapy modification
Ospemifene: RifAMPin may decrease the serum concentration of Ospemifene. Risk C: Monitor therapy
OXcarbazepine: CYP3A4 Inducers (Strong) may decrease the serum concentration of OXcarbazepine. Specifically, the concentrations of the 10-monohydroxy active metabolite of oxcarbazepine may be decreased. Risk C: Monitor therapy
OxyCODONE: CYP3A4 Inducers (Strong) may decrease the serum concentration of OxyCODONE. Risk C: Monitor therapy
Ozanimod: CYP2C8 Inducers (Moderate) may decrease serum concentrations of the active metabolite(s) of Ozanimod. CYP2C8 Inducers (Moderate) may decrease the serum concentration of Ozanimod. Risk X: Avoid combination
PACLitaxel (Conventional): CYP3A4 Inducers (Strong) may decrease the serum concentration of PACLitaxel (Conventional). Risk C: Monitor therapy
PACLitaxel (Protein Bound): CYP3A4 Inducers (Strong) may decrease the serum concentration of PACLitaxel (Protein Bound). Risk C: Monitor therapy
Palbociclib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Palbociclib. Risk X: Avoid combination
Paliperidone: Inducers of CYP3A4 (Strong) and P-glycoprotein may decrease the serum concentration of Paliperidone. Management: Monitor for reduced paliperidone effects when combined with strong inducers of both CYP3A4 and P-gp. Avoid use of these inducers with extended-release injectable paliperidone and instead manage patients with paliperidone extended-release tablets. Risk C: Monitor therapy
Panobinostat: CYP3A4 Inducers (Strong) may decrease the serum concentration of Panobinostat. Risk X: Avoid combination
PAZOPanib: CYP3A4 Inducers (Strong) may decrease the serum concentration of PAZOPanib. Risk X: Avoid combination
Pemigatinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Pemigatinib. Risk X: Avoid combination
Perampanel: CYP3A4 Inducers (Strong) may decrease the serum concentration of Perampanel. Management: Increase perampanel starting dose to 4 mg/day if used with strong CYP3A4 inducers. Increase perampanel dose by 2 mg/day no more than once weekly based on response and tolerability. Dose adjustments may be needed if the inducer is discontinued. Risk D: Consider therapy modification
Pexidartinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Pexidartinib. Risk X: Avoid combination
Pimavanserin: CYP3A4 Inducers (Strong) may decrease the serum concentration of Pimavanserin. Risk X: Avoid combination
Pioglitazone: CYP2C8 Inducers (Moderate) may decrease the serum concentration of Pioglitazone. Risk C: Monitor therapy
Piperaquine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Piperaquine. Risk X: Avoid combination
Pitavastatin: RifAMPin may increase the serum concentration of Pitavastatin. Management: Limit pitavastatin dose to a maximum of 2 mg/day with concurrent rifampin. Risk D: Consider therapy modification
Pitolisant: CYP3A4 Inducers (Strong) may decrease the serum concentration of Pitolisant. Management: If on a stable pitolisant dose of 8.9 mg or 17.8 mg/day and starting a strong CYP3A4 inducer, double the pitolisant dose over 7 days (ie, to either 17.8 mg/day or 35.6 mg/day, respectively). Reduce pitolisant dose by 50% when the inducer is discontinued. Risk D: Consider therapy modification
Polatuzumab Vedotin: CYP3A4 Inducers (Strong) may decrease the serum concentration of Polatuzumab Vedotin. Exposure to unconjugated MMAE, the cytotoxic small molecule component of polatuzumab vedotin, may be decreased. Risk C: Monitor therapy
PONATinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of PONATinib. Management: Avoid coadministration of ponatinib with strong CYP3A4 inducers unless the potential benefit of concomitant treatment outweighs the risk of reduced ponatinib exposure. Monitor patients for reduced ponatinib efficacy if combined. Risk D: Consider therapy modification
Ponesimod: UGT1A1 Inducers may decrease the serum concentration of Ponesimod. Risk X: Avoid combination
Posaconazole: RifAMPin may decrease the serum concentration of Posaconazole. Risk C: Monitor therapy
Pralsetinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Pralsetinib. Management: Avoid concomitant use of pralsetinib with strong CYP3A4 inducers when possible. If combined, increase the starting dose of pralsetinib to double the current pralsetinib dosage starting on day 7 of coadministration. Risk D: Consider therapy modification
Pravastatin: RifAMPin may decrease the serum concentration of Pravastatin. Risk C: Monitor therapy
Praziquantel: RifAMPin may decrease the serum concentration of Praziquantel. Risk X: Avoid combination
PrednisoLONE (Systemic): CYP3A4 Inducers (Strong) may decrease the serum concentration of PrednisoLONE (Systemic). Risk C: Monitor therapy
PredniSONE: CYP3A4 Inducers (Strong) may decrease the serum concentration of PredniSONE. Risk C: Monitor therapy
Pretomanid: CYP3A4 Inducers (Strong) may decrease the serum concentration of Pretomanid. Risk X: Avoid combination
Probenecid: May increase the serum concentration of RifAMPin. Risk C: Monitor therapy
Propacetamol: RifAMPin may enhance the hepatotoxic effect of Propacetamol. RifAMPin may increase the metabolism of Propacetamol. . This may 1) diminish the desired effects of propacetamol; and 2) increase the risk of liver damage. Risk C: Monitor therapy
Propafenone: CYP3A4 Inducers (Strong) may decrease the serum concentration of Propafenone. Risk C: Monitor therapy
Propofol: RifAMPin may enhance the hypotensive effect of Propofol. Management: Avoid this combination if possible. Use of propofol in a patient who has been taking rifampin may result in clinically significant hypotension. Risk D: Consider therapy modification
Propranolol: RifAMPin may decrease the serum concentration of Propranolol. Risk C: Monitor therapy
Prothionamide: RifAMPin may enhance the hepatotoxic effect of Prothionamide. Management: Avoid concomitant use of prothionamide and rifampin if possible. If combined use is considered necessary, monitor patients closely for signs and symptoms of hepatotoxicity (eg, jaundice, elevations in liver function tests). Risk D: Consider therapy modification
Pyrazinamide: May enhance the hepatotoxic effect of RifAMPin. Severe (even fatal) liver injury has been reported in patients receiving these 2 drugs as a 2-month treatment regimen for latent TB infection. Management: Rifampin-pyrazinamide is generally not preferred for the treatment of latent tuberculosis (TB) due to the risk of hepatotoxicity. However, it is an option for patients at high risk of developing active TB who are unlikely to complete preferred treatment. Risk D: Consider therapy modification
QUEtiapine: CYP3A4 Inducers (Strong) may decrease the serum concentration of QUEtiapine. Management: An increase in quetiapine dose (as much as 5 times the regular dose) may be required to maintain therapeutic benefit. Reduce the quetiapine dose back to the previous/regular dose within 7 to 14 days of discontinuing the inducer. Risk D: Consider therapy modification
QuiNIDine: CYP3A4 Inducers (Strong) may decrease the serum concentration of QuiNIDine. Risk C: Monitor therapy
QuiNINE: RifAMPin may decrease the serum concentration of QuiNINE. Risk X: Avoid combination
Radotinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Radotinib. Management: Consider alternatives to this combination when possible as the risk of radotinib treatment failure may be increased. Risk D: Consider therapy modification
Raltegravir: RifAMPin may decrease the serum concentration of Raltegravir. Management: Increase raltegravir dose to 800 mg twice daily (adult dose) when used concomitantly with rifampin. Concurrent use of rifampin with once-daily raltegravir (Isentress HD) is not recommended. Risk D: Consider therapy modification
Ramelteon: CYP3A4 Inducers (Strong) may decrease the serum concentration of Ramelteon. Risk C: Monitor therapy
Ranolazine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Ranolazine. Risk X: Avoid combination
Reboxetine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Reboxetine. Risk C: Monitor therapy
Red Yeast Rice: RifAMPin may decrease the serum concentration of Red Yeast Rice. Risk C: Monitor therapy
Regorafenib: CYP3A4 Inducers (Strong) may increase serum concentrations of the active metabolite(s) of Regorafenib. CYP3A4 Inducers (Strong) may decrease the serum concentration of Regorafenib. Risk X: Avoid combination
Relugolix: Inducers of CYP3A4 (Strong) and P-glycoprotein may decrease the serum concentration of Relugolix. Management: Avoid use of relugolix with drugs that are both strong CYP3A4 and P-glycoprotein (P-gp) inducer. If combined, increase the dose of relugolix to 240 mg once daily. Reduce back to 120 mg daily once the combined inducer is discontinued. Risk D: Consider therapy modification
Relugolix, Estradiol, and Norethindrone: Inducers of CYP3A4 (Strong) and P-glycoprotein may decrease the serum concentration of Relugolix, Estradiol, and Norethindrone. Risk X: Avoid combination
Remdesivir: CYP3A4 Inducers (Strong) may decrease the serum concentration of Remdesivir. Risk C: Monitor therapy
Repaglinide: RifAMPin may decrease the serum concentration of Repaglinide. Risk C: Monitor therapy
Revefenacin: OATP1B1/1B3 (SLCO1B1/1B3) Inhibitors may increase serum concentrations of the active metabolite(s) of Revefenacin. Risk X: Avoid combination
Ribociclib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Ribociclib. Risk X: Avoid combination
Rifabutin: CYP3A4 Inducers (Strong) may decrease the serum concentration of Rifabutin. Risk C: Monitor therapy
Rilpivirine: RifAMPin may decrease the serum concentration of Rilpivirine. Risk X: Avoid combination
Rimegepant: CYP3A4 Inducers (Strong) may decrease the serum concentration of Rimegepant. Risk X: Avoid combination
Riociguat: CYP3A4 Inducers (Strong) may decrease the serum concentration of Riociguat. Risk C: Monitor therapy
Ripretinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Ripretinib. Risk X: Avoid combination
RisperiDONE: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of RisperiDONE. CYP3A4 Inducers (Strong) may decrease the serum concentration of RisperiDONE. Management: Careful monitoring for reduced risperidone efficacy and possible dose adjustment are recommended when combined with strong CYP3A4 inducers. See full interaction monograph for details. Risk D: Consider therapy modification
Ritonavir: RifAMPin may increase the serum concentration of Ritonavir. RifAMPin may decrease the serum concentration of Ritonavir. Risk X: Avoid combination
Rivaroxaban: Inducers of CYP3A4 (Strong) and P-glycoprotein may decrease the serum concentration of Rivaroxaban. Risk X: Avoid combination
Roflumilast: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Roflumilast. CYP3A4 Inducers (Strong) may decrease the serum concentration of Roflumilast. Risk X: Avoid combination
Rolapitant: CYP3A4 Inducers (Strong) may decrease the serum concentration of Rolapitant. Risk X: Avoid combination
RomiDEPsin: RifAMPin may increase the serum concentration of RomiDEPsin. Risk X: Avoid combination
Rosiglitazone: CYP2C8 Inducers (Moderate) may decrease the serum concentration of Rosiglitazone. Risk C: Monitor therapy
Rosuvastatin: RifAMPin may decrease the serum concentration of Rosuvastatin. Risk C: Monitor therapy
Ruxolitinib (Systemic): CYP3A4 Inducers (Strong) may increase serum concentrations of the active metabolite(s) of Ruxolitinib (Systemic). CYP3A4 Inducers (Strong) may decrease the serum concentration of Ruxolitinib (Systemic). Risk C: Monitor therapy
Sacituzumab Govitecan: UGT1A1 Inducers may decrease serum concentrations of the active metabolite(s) of Sacituzumab Govitecan. Specifically, concentrations of SN-38 may be decreased. Risk X: Avoid combination
Samidorphan: CYP3A4 Inducers (Strong) may decrease the serum concentration of Samidorphan. Risk X: Avoid combination
Saquinavir: RifAMPin may enhance the adverse/toxic effect of Saquinavir. Specifically, the risk of hepatocellular toxicity may be increased. RifAMPin may decrease the serum concentration of Saquinavir. Risk X: Avoid combination
SAXagliptin: CYP3A4 Inducers (Strong) may decrease the serum concentration of SAXagliptin. Risk C: Monitor therapy
Selexipag: RifAMPin may decrease serum concentrations of the active metabolite(s) of Selexipag. Management: Increase the selexipag dose (up to 2-fold) when combined with rifampin. Monitor for decreased selexipag efficacy. Risk D: Consider therapy modification
Selpercatinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Selpercatinib. Risk X: Avoid combination
Selumetinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Selumetinib. Risk X: Avoid combination
Sertraline: CYP3A4 Inducers (Strong) may decrease the serum concentration of Sertraline. Risk C: Monitor therapy
Sildenafil: CYP3A4 Inducers (Strong) may decrease the serum concentration of Sildenafil. Risk C: Monitor therapy
Simeprevir: CYP3A4 Inducers (Strong) may decrease the serum concentration of Simeprevir. Risk X: Avoid combination
Simvastatin: RifAMPin may decrease the serum concentration of Simvastatin. Risk C: Monitor therapy
Siponimod: RifAMPin may decrease the serum concentration of Siponimod. Risk X: Avoid combination
Sirolimus (Conventional): CYP3A4 Inducers (Strong) may decrease the serum concentration of Sirolimus (Conventional). Management: Avoid concomitant use of strong CYP3A4 inducers and sirolimus if possible. If combined, monitor for reduced serum sirolimus concentrations. Sirolimus dose increases will likely be necessary to prevent subtherapeutic sirolimus levels. Risk D: Consider therapy modification
Sirolimus (Protein Bound): CYP3A4 Inducers (Strong) may decrease the serum concentration of Sirolimus (Protein Bound). Risk X: Avoid combination
Sodium Picosulfate: Antibiotics may diminish the therapeutic effect of Sodium Picosulfate. Management: Consider using an alternative product for bowel cleansing prior to a colonoscopy in patients who have recently used or are concurrently using an antibiotic. Risk D: Consider therapy modification
Sofosbuvir: P-glycoprotein/ABCB1 Inducers may decrease the serum concentration of Sofosbuvir. Risk X: Avoid combination
Solifenacin: CYP3A4 Inducers (Strong) may decrease the serum concentration of Solifenacin. Risk C: Monitor therapy
Sonidegib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Sonidegib. Risk X: Avoid combination
SORAfenib: CYP3A4 Inducers (Strong) may decrease the serum concentration of SORAfenib. Risk X: Avoid combination
Sotorasib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Sotorasib. Risk X: Avoid combination
Stiripentol: CYP3A4 Inducers (Strong) may decrease the serum concentration of Stiripentol. Management: Avoid concomitant use of stiripentol and strong CYP3A4 inducers when possible. If combined, monitor for reduced stiripentol efficacy and increase the stiripentol dose as needed. Risk D: Consider therapy modification
SUFentanil: CYP3A4 Inducers (Strong) may decrease the serum concentration of SUFentanil. Management: If a strong CYP3A4 inducer is initiated in a patient on sufentanil, consider a sufentanil dose increase and monitor for decreased sufentanil effects and opioid withdrawal symptoms. Risk D: Consider therapy modification
Sulfamethoxazole: May increase the serum concentration of RifAMPin. RifAMPin may decrease the serum concentration of Sulfamethoxazole. Risk C: Monitor therapy
Sulfonylureas: CYP2C9 Inducers (Moderate) may decrease the serum concentration of Sulfonylureas. Risk C: Monitor therapy
SUNItinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of SUNItinib. Management: Avoid when possible. If combined, increase sunitinib dose to a max of 87.5 mg daily when treating GIST or RCC. Increase sunitinib dose to a max of 62.5 mg daily when treating PNET. Monitor patients for both reduced efficacy and increased toxicities. Risk D: Consider therapy modification
Suvorexant: CYP3A4 Inducers (Strong) may decrease the serum concentration of Suvorexant. Risk C: Monitor therapy
Tacrolimus (Systemic): CYP3A4 Inducers (Strong) may decrease the serum concentration of Tacrolimus (Systemic). Management: Monitor for decreased tacrolimus concentrations and effects when combined with strong CYP3A4 inducers. Tacrolimus dose increases will likely be needed during concomitant use. Risk D: Consider therapy modification
Tadalafil: CYP3A4 Inducers (Strong) may decrease the serum concentration of Tadalafil. Management: Erectile dysfunction or benign prostatic hypertrophy: monitor for decreased effectiveness - no standard dose adjustment is recommended. Avoid use of tadalafil for pulmonary arterial hypertension in patients receiving a strong CYP3A4 inducer. Risk D: Consider therapy modification
Tamoxifen: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Tamoxifen. CYP3A4 Inducers (Strong) may decrease the serum concentration of Tamoxifen. Risk X: Avoid combination
Tasimelteon: CYP3A4 Inducers (Strong) may decrease the serum concentration of Tasimelteon. Risk X: Avoid combination
Tazemetostat: CYP3A4 Inducers (Strong) may decrease the serum concentration of Tazemetostat. Risk X: Avoid combination
Telithromycin: CYP3A4 Inducers (Strong) may decrease the serum concentration of Telithromycin. Risk X: Avoid combination
Temsirolimus: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Temsirolimus. Specifically, concentrations of sirolimus may be decreased. CYP3A4 Inducers (Strong) may decrease the serum concentration of Temsirolimus. Management: Avoid concomitant use of temsirolimus and strong CYP3A4 inducers. If coadministration is unavoidable, increase temsirolimus dose to 50 mg per week. Resume previous temsirolimus dose after discontinuation of the strong CYP3A4 inducer. Risk D: Consider therapy modification
Teniposide: CYP3A4 Inducers (Strong) may decrease the serum concentration of Teniposide. Risk C: Monitor therapy
Tenofovir Alafenamide: RifAMPin may decrease the serum concentration of Tenofovir Alafenamide. Risk X: Avoid combination
Tepotinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Tepotinib. Risk X: Avoid combination
Terbinafine (Systemic): RifAMPin may decrease the serum concentration of Terbinafine (Systemic). Risk C: Monitor therapy
Tertatolol: RifAMPin may decrease the serum concentration of Tertatolol. Risk C: Monitor therapy
Tetrahydrocannabinol: CYP3A4 Inducers (Strong) may decrease the serum concentration of Tetrahydrocannabinol. Risk C: Monitor therapy
Tetrahydrocannabinol and Cannabidiol: CYP3A4 Inducers (Strong) may decrease the serum concentration of Tetrahydrocannabinol and Cannabidiol. Management: Avoid use of the tetrahydrocannabinol/cannabidiol oromucosal spray and strong CYP3A4 inducers when possible. If combined use is necessary, careful titration is recommended, notably within the two weeks following discontinuation of the inducer. Risk D: Consider therapy modification
Tezacaftor and Ivacaftor: CYP3A4 Inducers (Strong) may decrease the serum concentration of Tezacaftor and Ivacaftor. Risk X: Avoid combination
Theophylline Derivatives: RifAMPin may decrease the serum concentration of Theophylline Derivatives. Risk C: Monitor therapy
Thiotepa: CYP3A4 Inducers (Strong) may increase serum concentrations of the active metabolite(s) of Thiotepa. CYP3A4 Inducers (Strong) may decrease the serum concentration of Thiotepa. Management: Thiotepa prescribing information recommends avoiding concomitant use of thiotepa and strong CYP3A4 inducers. If concomitant use is unavoidable, monitor for adverse effects. Risk D: Consider therapy modification
Thyroid Products: RifAMPin may decrease the serum concentration of Thyroid Products. Risk C: Monitor therapy
TiaGABine: CYP3A4 Inducers (Strong) may decrease the serum concentration of TiaGABine. Risk C: Monitor therapy
Ticagrelor: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Ticagrelor. CYP3A4 Inducers (Strong) may decrease the serum concentration of Ticagrelor. Risk X: Avoid combination
Tipranavir: RifAMPin may decrease the serum concentration of Tipranavir. Risk X: Avoid combination
Tivozanib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Tivozanib. Risk X: Avoid combination
Tofacitinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Tofacitinib. Risk X: Avoid combination
Tolvaptan: CYP3A4 Inducers (Strong) may decrease the serum concentration of Tolvaptan. Risk X: Avoid combination
Toremifene: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Toremifene. CYP3A4 Inducers (Strong) may decrease the serum concentration of Toremifene. Risk X: Avoid combination
Torsemide: CYP2C9 Inducers (Moderate) may decrease the serum concentration of Torsemide. Risk C: Monitor therapy
Trabectedin: CYP3A4 Inducers (Strong) may decrease the serum concentration of Trabectedin. Risk X: Avoid combination
TraMADol: CYP3A4 Inducers (Strong) may decrease the serum concentration of TraMADol. Risk C: Monitor therapy
TraZODone: CYP3A4 Inducers (Strong) may decrease the serum concentration of TraZODone. Management: Consider increasing the trazodone dose during coadministration with strong CYP3A4 inducers. Risk D: Consider therapy modification
Triamcinolone (Systemic): CYP3A4 Inducers (Strong) may decrease the serum concentration of Triamcinolone (Systemic). Risk C: Monitor therapy
Triazolam: CYP3A4 Inducers (Strong) may decrease the serum concentration of Triazolam. Management: Consider alternatives to this combination when possible. If combined, monitor for reduced triazolam efficacy. Substantial triazolam dose increases will likely be required. Risk D: Consider therapy modification
Trimethoprim: May increase the serum concentration of RifAMPin. RifAMPin may decrease the serum concentration of Trimethoprim. Risk C: Monitor therapy
Tropisetron: CYP3A4 Inducers (Strong) may decrease the serum concentration of Tropisetron. Risk C: Monitor therapy
Tucatinib: CYP2C8 Inducers (Moderate) may decrease the serum concentration of Tucatinib. Risk X: Avoid combination
Typhoid Vaccine: Antibiotics may diminish the therapeutic effect of Typhoid Vaccine. Only the live attenuated Ty21a strain is affected. Management: Avoid use of live attenuated typhoid vaccine (Ty21a) in patients being treated with systemic antibacterial agents. Postpone vaccination until 3 days after cessation of antibiotics and avoid starting antibiotics within 3 days of last vaccine dose. Risk D: Consider therapy modification
Ubrogepant: CYP3A4 Inducers (Strong) may decrease the serum concentration of Ubrogepant. Risk X: Avoid combination
Udenafil: CYP3A4 Inducers (Strong) may decrease the serum concentration of Udenafil. Risk C: Monitor therapy
Ulipristal: CYP3A4 Inducers (Strong) may decrease the serum concentration of Ulipristal. Risk X: Avoid combination
Upadacitinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Upadacitinib. Risk X: Avoid combination
Valbenazine: CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Valbenazine. CYP3A4 Inducers (Strong) may decrease the serum concentration of Valbenazine. Risk X: Avoid combination
Valproate Products: RifAMPin may decrease the serum concentration of Valproate Products. Risk C: Monitor therapy
Vandetanib: CYP3A4 Inducers (Strong) may increase serum concentrations of the active metabolite(s) of Vandetanib. CYP3A4 Inducers (Strong) may decrease the serum concentration of Vandetanib. Risk X: Avoid combination
Velpatasvir: CYP2B6 Inducers (Moderate) may decrease the serum concentration of Velpatasvir. Risk X: Avoid combination
Velpatasvir: CYP3A4 Inducers (Strong) may decrease the serum concentration of Velpatasvir. Risk X: Avoid combination
Vemurafenib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Vemurafenib. Management: Avoid coadministration of vemurafenib and strong CYP3A4 inducers if possible. If coadministration is unavoidable, increase the vemurafenib dose by 240 mg as tolerated. Resume prior vemurafenib dose 2 weeks after discontinuation of strong CYP3A4 inducer. Risk D: Consider therapy modification
Venetoclax: CYP3A4 Inducers (Strong) may decrease the serum concentration of Venetoclax. Risk X: Avoid combination
Verapamil: CYP3A4 Inducers (Strong) may decrease the serum concentration of Verapamil. Management: Consider alternatives to this combination. If combined, monitor for reduced verapamil efficacy. Verapamil dose increases may be necessary. Risk D: Consider therapy modification
Vilazodone: CYP3A4 Inducers (Strong) may decrease the serum concentration of Vilazodone. Management: Consider increasing vilazodone dose by as much as 2-fold (do not exceed 80 mg/day), based on response, in patients receiving strong CYP3A4 inducers for > 14 days. Reduce to the original vilazodone dose over 1 to 2 weeks after inducer discontinuation. Risk D: Consider therapy modification
VinCRIStine: CYP3A4 Inducers (Strong) may decrease the serum concentration of VinCRIStine. Risk C: Monitor therapy
VinCRIStine (Liposomal): CYP3A4 Inducers (Strong) may decrease the serum concentration of VinCRIStine (Liposomal). Risk X: Avoid combination
VinCRIStine (Liposomal): P-glycoprotein/ABCB1 Inducers may decrease the serum concentration of VinCRIStine (Liposomal). Risk X: Avoid combination
Vinflunine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Vinflunine. Risk X: Avoid combination
Vinorelbine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Vinorelbine. Risk C: Monitor therapy
Vitamin K Antagonists (eg, warfarin): Rifamycin Derivatives may decrease the serum concentration of Vitamin K Antagonists. Management: Consider alternatives if possible. If combined, monitor for reduced anticoagulant effects if a rifamycin derivative is initiated in a vitamin K antagonist treated patient. Vitamin K antagonist dose adjustments will likely be required. Risk D: Consider therapy modification
Voclosporin: CYP3A4 Inducers (Strong) may decrease the serum concentration of Voclosporin. Risk X: Avoid combination
Vorapaxar: CYP3A4 Inducers (Strong) may decrease the serum concentration of Vorapaxar. Risk X: Avoid combination
Voriconazole: RifAMPin may decrease the serum concentration of Voriconazole. Risk X: Avoid combination
Vortioxetine: CYP3A4 Inducers (Strong) may decrease the serum concentration of Vortioxetine. Management: Consider increasing the vortioxetine dose to no more than 3 times the original dose when used with a strong drug metabolism inducer for more than 14 days. The vortioxetine dose should be returned to normal within 14 days of stopping the strong inducer. Risk D: Consider therapy modification
Voxelotor: CYP3A4 Inducers (Strong) may decrease the serum concentration of Voxelotor. Management: Avoid concomitant use of voxelotor and strong CYP3A4 inducers. If unavoidable, increase the voxelotor dose to 2,500 mg once daily. For children ages 4 to less than 12 years, weight-based dose adjustments are required. See full monograph for details. Risk D: Consider therapy modification
Voxilaprevir: RifAMPin may increase the serum concentration of Voxilaprevir. Specifically, a single dose of rifampin may increase voxilaprevir concentrations, while chronic daily use of rifampin may decrease voxilaprevir concentrations. RifAMPin may decrease the serum concentration of Voxilaprevir. Risk X: Avoid combination
Zaleplon: CYP3A4 Inducers (Strong) may decrease the serum concentration of Zaleplon. Management: Consider the use of an alternative hypnotic that is not metabolized by CYP3A4 in patients receiving strong CYP3A4 inducers. If zaleplon is combined with a strong CYP3A4 inducer, monitor for decreased effectiveness of zaleplon. Risk D: Consider therapy modification
Zanubrutinib: CYP3A4 Inducers (Strong) may decrease the serum concentration of Zanubrutinib. Risk X: Avoid combination
Zidovudine: RifAMPin may decrease the serum concentration of Zidovudine. Risk C: Monitor therapy
Zolpidem: CYP3A4 Inducers (Strong) may decrease the serum concentration of Zolpidem. Risk C: Monitor therapy
Zonisamide: CYP3A4 Inducers (Strong) may decrease the serum concentration of Zonisamide. Risk C: Monitor therapy
Zopiclone: CYP3A4 Inducers (Strong) may decrease the serum concentration of Zopiclone. Risk C: Monitor therapy
Zuclopenthixol: CYP3A4 Inducers (Strong) may decrease the serum concentration of Zuclopenthixol. Risk C: Monitor therapy
Food decreases the extent of absorption; rifampin concentrations may be decreased if taken with food. Management: Administer on an empty stomach with a glass of water (ie, 1 hour prior to, or 2 hours after meals or antacids).
Rifampin may decrease the effectiveness of hormonal contraceptives. Consult drug interactions database for more detailed information specific to use of rifampin and specific contraceptives.
Rifampin crosses the human placenta. Postnatal hemorrhages have been reported in the infant and mother with administration during the last few weeks of pregnancy.
Rifampin is approved for the treatment of tuberculosis. Active tuberculosis infection is associated with adverse fetal outcomes, including intrauterine growth restriction, low birth weight, preterm birth, and perinatal death (Esmail 2018; Miele 2020), as well as adverse maternal outcomes, including increased risks for anemia and cesarean delivery. Placental transmission may rarely occur with active maternal disease (Miele 2020). Due to the risks of untreated tuberculosis, rifampin is recommended as part of the initial treatment regimen of drug-susceptible active tuberculosis when the probability of maternal disease is moderate to high (ATS/CDC/IDSA [Nahid 2016]). Rifampin may also be considered for the treatment of latent tuberculosis infection (also known as prophylaxis or preventive therapy) in pregnant patients (WHO 2020). Rifampin may be associated with an increased risk of maternal hepatotoxicity, which may require temporary drug withdrawal in pregnant and postpartum patients (Beck-Friis 2020).
Rifampin is used off-label for the treatment of brucellosis infection. Brucellosis infection may increase the risk of spontaneous abortion; rifampin is recommended for the treatment of brucellosis infection during pregnancy (CDC 2017).
Rifampin may be considered for use as an alternative agent in pregnant patients for the treatment of mild illness due to human anaplasmosis (also known as human granulocytic anaplasmosis); case reports have shown favorable maternal and pregnancy outcomes in small numbers of rifampin-treated pregnant women (CDC [Biggs 2016]).
Rifampin is present in breast milk (Vorherr 1974).
Due to the potential for serious adverse reactions in the breastfeeding infant, the manufacturer recommends a decision be made whether to discontinue breastfeeding or to discontinue the drug, considering the importance of treatment to the mother. Breastfeeding is not a contraindication during therapy for drug-susceptible tuberculosis in patients deemed noninfectious who are treated with first-line agents (ie, rifampin). Exposure to rifampin via breast milk should not be considered effective treatment for the breastfeeding infant (ATS/CDC/IDSA [Nahid 2016]).
Baseline LFTs (AST, ALT, bilirubin), serum creatinine, CBC; periodic (every 2 to 4 weeks during therapy) monitoring of liver function in patients with preexisting hepatic impairment and periodic monitoring of serum creatinine and CBC in patients with baseline abnormalities. Mental status, sputum culture, chest X-ray 2 to 3 months into treatment. Monitor coagulation tests during treatment in patients at risk of vitamin K deficiency. Check platelets, renal function tests, serum lactate dehydrogenase, blood film for schistocytes (erythrocyte fragmentation), ADAMTS13 activity, and anti-ADAMTS13-antibody determination in patients with suspected thrombotic microangiopathy or hemolytic uremic syndrome. Monitor for symptoms of interstitial lung disease/pneumonitis in patients being treated for tuberculosis. Monitor for signs and symptoms of liver injury, especially if treatment is prolonged or given in combination with other hepatotoxic drugs.
TB treatment: Target peak: ≥8 mcg/mL at 2 and 6 hours post-dose (Alsultan 2014)
Inhibits bacterial RNA synthesis by binding to the beta subunit of DNA-dependent RNA polymerase, blocking RNA transcription
Duration: ≤24 hours.
Absorption: Oral: Well absorbed; food may delay or slightly reduce peak.
Distribution: Highly lipophilic; crosses blood-brain barrier well.
Vd: Neonates, Infants, Children, and Adolescents: ~1.1 L/kg (Nahata 1990; Smith 2019).
Relative diffusion from blood into CSF: Adequate with or without inflammation (exceeds usual MICs).
CSF:blood level ratio: Inflamed meninges: 25%.
Protein binding: 80%.
Metabolism: Hepatic; undergoes enterohepatic recirculation.
Half-life elimination:
Neonates and Infants <4 months (GA ≥23 weeks): PNA <14 days: Median: 7.1 hours (range: 3 to 23.9 hours); PNA ≥14 days: Median: 3.5 hours (range: 1.9 to 6.5 hours) (Smith 2019).
Infants and Children 6 months to <5 years: ~1 to 4 hours.
Adults: ~2 to 3 hours (steady-state).
Time to peak, serum:
Infants and Children 6 months to <5 years: Oral: 1 hour.
Adults: Oral: ~2 hours (Acocella 1978).
Excretion: Feces (60% to 65%) and urine (~30%) as unchanged drug.
Altered kidney function: Half-life prolonged from 3.6 hours (GFR >50 mL/minute) to 5 hours (GFR 30 to 50 mL/minute), 7.3 hours (GFR <30 mL/minute) and 11 hours (patients who are anuric) following a single 900 mg dose. No increase in half-life has been observed with doses ≤600 mg/day.
Capsules (rifAMPin Oral)
150 mg (per each): $1.58 - $4.16
300 mg (per each): $1.33 - $5.85
Solution (reconstituted) (Rifadin Intravenous)
600 mg (per each): $214.27
Solution (reconstituted) (rifAMPin Intravenous)
600 mg (per each): $183.60 - $192.63
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