Pyridoxine deficiency: IM, IV: 10 to 20 mg/day for 3 weeks, followed by daily oral therapy for several weeks. Doses up to 600 mg/day may be needed with pyridoxine dependency syndrome.
Ethylene glycol poisoning (off-label use): Note: Cofactors are adjunctive to antidotal therapy and should never be used alone.
IV: 100 mg per day until the intoxication has resolved (Howland 2018).
Gyromitrin-containing mushroom (false morel) overdose/toxicity (treatment/prophylaxis) (off-label use): Note: Dosing recommendations are based on the use of pyridoxine for the treatment and prevention of neurological toxicities associated with isoniazid overdose (Goldfrank 2018).
IV: Initial: 5 g; administer at a rate of 0.5 to 1 g/minute; may repeat every 5 to 10 minutes as needed to control persistent seizure activity and/or CNS toxicity (Howland 2018; Morrow 2006).
Nausea and vomiting of pregnancy (off-label use): Oral: 10 to 25 mg 3 to 4 times a day. May be given alone or in combination with doxylamine. Adjust dose based on severity of symptoms (ACOG 189 2018).
Neurological toxicities (ie, seizures, coma) associated with isoniazid overdose (prevention) (off-label use): IV: Asymptomatic patients who present within 2 hours of ingesting a potentially toxic amount of isoniazid should receive a prophylactic dose of pyridoxine (Hernon 2015). Dosing recommendations are the same as for the treatment of symptomatic patients.
Neurological toxicities (ie, seizures, coma) associated with isoniazid overdose (treatment) (off-label use): IV:
Acute ingestion of known amount: Initial: A total dose of pyridoxine equal to the amount of isoniazid ingested (maximum dose: 5 g); administer at a rate of 0.5 to 1 g/minute until seizures stop or the maximum initial dose has been administered; may repeat every 5 to 10 minutes as needed to control persistent seizure activity and/or CNS toxicity. If seizures stop prior to the administration of the calculated initial dose, infuse the remaining pyridoxine over 4 to 6 hours (Howland 2018; Morrow 2006).
Acute ingestion of unknown amount: Initial: 5 g; administer at a rate of 0.5 to 1 g/minute; may repeat every 5 to 10 minutes as needed to control persistent seizure activity and/or CNS toxicity (Howland 2018; Morrow 2006).
Peripheral neuropathy associated with isoniazid therapy for Mycobacterium tuberculosis (prevention): Oral:
Daily isoniazid regimen: 25 to 50 mg/day (CDC [Kaplan 2009]).
Weekly isoniazid/rifapentine regimen: 50 mg once weekly (HHS [Adult OI 2020]).
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.
There are no dosage adjustments provided in the manufacturer’s labeling.
(For additional information see "Vitamin B6 (pyridoxine): Pediatric drug information")
Pyridoxine deficiency; treatment:
Children: Oral, IM, IV: 5 to 25 mg/day for 3 weeks, then 2.5 to 5 mg/day in multivitamin product (Gal 2007).
Adolescents: Oral, IM, IV: 10 to 20 mg/day for 3 weeks, then 2 to 5 mg/day (usual dosage found in multivitamin products) (Gal 2007).
Pyridoxine-dependent seizures, treatment: Limited data available:
Infants and Children:
Initial: Acute, active seizure: Note: Administration should occur in intensive care unit due to possible apnea episodes (may require intubation); with oral administration, therapeutic response and adverse effect (ie, apnea) may be delayed in presentation; monitor patients closely (Stockler 2011).
IV (preferred): 100 mg/dose; may repeat dose over the course of 30 minutes (Stockler 2011).
Oral (when IV not feasible): 30 mg/kg/day for several days (Stockler 2011).
Maintenance: Oral: Usual dose: 15 to 30 mg/kg/day not to exceed 500 mg/day (Baxter 1999; NORD 2017; Stockler 2011).
Drug-induced deficiency (cycloserine, isoniazid, penicillamine); chronic use:
Isoniazid/Cycloserine:
Prevention: Note: Recommended for patients at risk: Exclusively breastfed infants, meat- and milk-deficient diet, nutritional deficiency, pregnant adolescents, HIV-infected patients (HHS [OI pediatric 2019]); Red Book [AAP 2018]).
Infants and Children: Oral: 1 to 2 mg/kg once daily; maximum daily dose: 50 mg/day (HHS [OI pediatric 2019]).
Adolescents: Oral: 25 to 50 mg/day (ATS/CDC/IDSA [Nahid 2016]); HHS [OI adult 2019]).
Penicillamine (in Wilson Disease patients): Limited data available: Children and Adolescents: Oral: 25 to 50 mg/day (Roberts 2008).
Acute isoniazid ingestion:
Treatment of isoniazid-induced seizures and/or coma: IV: Children and Adolescents:
Acute ingestion of known amount: Initial: A total dose of pyridoxine equal to the amount of isoniazid ingested (maximum dose: 70 mg/kg up to 5 g); administer at a rate of 0.5 to 1 g/minute until seizures stop or the maximum initial dose has been administered; may repeat every 5 to 10 minutes as needed to control persistent seizure activity and/or CNS toxicity. If seizures stop prior to the administration of the calculated initial dose, infuse the remaining pyridoxine over 4 to 6 hours (Howland 2015; Morrow 2006).
Acute ingestion of unknown amount: Initial: 70 mg/kg (maximum dose: 5 g); administer at a rate of 0.5 to 1 g/minute; may repeat every 5 to 10 minutes as needed to control persistent seizure activity and/or CNS toxicity (Howland 2015; Morrow 2006; Santucci 1999)
Prevention of isoniazid-induced seizures and/or coma: IV: Children: Asymptomatic patients who present within 2 hours of ingesting a potentially toxic amount of isoniazid should receive a prophylactic dose of pyridoxine (Hernon 2015). Dosing recommendations are the same as for the treatment of symptomatic patients.
Acute intoxication; mushroom ingestion (genus Gyromitra ): Children and Adolescents: IV: 25 mg/kg/dose; repeat as necessary to a maximum total dose of 15 to 20 g (Berger 2005).
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.
There are no dosage adjustments provided in the manufacturer's labeling.
Refer to adult dosing.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Capsule, Oral, as hydrochloride:
Neuro-K-250 T.D.: 250 mg [DSC] [corn free, rye free, starch free, sugar free, wheat free]
Solution, Injection, as hydrochloride:
Generic: 100 mg/mL (1 mL)
Tablet, Oral, as hydrochloride:
Neuro-K-50: 50 mg [DSC]
Neuro-K-500: 500 mg [DSC]
Neuro-K-250 Vitamin B6: 250 mg [DSC]
Pyri 500: 500 mg
Generic: 25 mg, 50 mg, 100 mg, 250 mg
Tablet, Oral, as hydrochloride [preservative free]:
Generic: 25 mg, 50 mg, 100 mg [DSC]
Tablet Extended Release, Oral, as hydrochloride:
Generic: 200 mg
May be product dependent
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Solution, Injection, as hydrochloride:
Generic: 100 mg/mL (10 mL, 30 mL)
Oral: Bariatric surgery: Tablet, extended release: Some institutions may have specific protocols that conflict with these recommendations; refer to institutional protocols as appropriate. ER tablets should be swallowed whole. Do not break, crush, or chew. IR tablet, capsule, and injectable formulations are available. If safety and efficacy can be effectively monitored, no change in formulation or administration is required after bariatric surgery. Bariatric vitamin supplementation is recommended on a lifelong basis after surgery; may consider integration of daily pyridoxine regimen into the bariatric vitamin in appropriate clinical scenarios.
Injection: Administer IM or IV.
Gyromitrin-containing mushroom (false morel) overdose/toxicity (off-label use); isoniazid toxicity (off-label use): Initial doses should be administered IV at a rate of 0.5 to 1 g/minute. If the parenteral formulation is not available, anecdotal reports suggest that pyridoxine tablets may be crushed and made into a slurry and given at the same dose orally or via NG tube (Hernon 2015). Oral administration is not recommended for acutely poisoned patients with seizure activity.
Oral: Administer without regard to meals.
Isoniazid acute ingestion/poisoning: If the parenteral formulation is not available, anecdotal reports suggest that pyridoxine tablets may be crushed and made into a slurry and administered at the same dose orally or via NG tube (Boyer 2006) or an extemporaneous compounded solution may be used. Oral administration is not recommended for acutely poisoned patients with seizure activity.
Parenteral: May be administered IM or slow IV; seizures have been precipitated following large IV doses.
Isoniazid toxicity: Initial IV doses should be administered at a rate of 500 to 1,000 mg/minute.
Pyridoxine deficiency: Treatment and prevention of pyridoxine (vitamin B6) deficiency.
Ethylene glycol poisoning; Gyromitrin-containing mushroom (false morel) overdose/toxicity (treatment/prophylaxis); Nausea and vomiting of pregnancy; Neurological toxicities (ie, seizures, coma) associated with isoniazid overdose (prevention); Neurological toxicities (ie, seizures, coma) associated with isoniazid overdose (treatment); Peripheral neuropathy associated with isoniazid therapy for Mycobacterium tuberculosis (prevention)
Pyridoxine may be confused with paroxetine, pralidoxime, Pyridium
Doxal [Brazil] may be confused with Doxil brand name for DOXOrubicin [U.S.]
Doxal: Brand name for pyridoxine/thiamine combination [Brazil], but also the brand name for doxepin [Finland]
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified. Frequency not defined.
Central nervous system: Ataxia, drowsiness, headache, neuropathy, paresthesia, seizure (following very large IV doses)
Endocrine & metabolic: Acidosis, folate deficiency
Gastrointestinal: Nausea
Hepatic: Increased serum AST
Hypersensitivity: Hypersensitivity reaction
Hypersensitivity to pyridoxine or any component of the formulation
Concerns related to adverse effects:
• Neuropathy: Severe, permanent peripheral neuropathies have been reported; neurotoxicity is more common with long-term administration of large doses (in adults: >2 g/day) (Albin 1987).
Dosage form specific issues:
• Aluminum: The parenteral product may contain aluminum; toxic aluminum concentrations may be seen with high doses, prolonged use, or renal impairment. Premature neonates are at higher risk due to immature renal function and aluminum intake from other parenteral sources. Parenteral aluminum exposure of >4 to 5 mcg/kg/day is associated with CNS and bone toxicity; tissue loading may occur at lower doses (Federal Register 2002). See manufacturer’s labeling.
Other warnings/precautions:
• Dependence/withdrawal: Doses >200 mg/day may cause dependence and withdrawal.
• Pharmacy supply of emergency antidotes: Guidelines suggest that at least 8 to 24 g be stocked. This is enough to treat 1 patient weighing 100 kg for an initial 8- to 24-hour period. In areas where tuberculosis is common and isoniazid toxicity is more likely, hospitals should consider stocking 24 g. This is enough to treat 1 patient for 24 hours (Dart 2018).
• Vitamin deficiency: Single vitamin deficiency is rare; evaluate for other deficiencies.
Higher doses (oral doses >30 mg/kg/day) have been associated with sensory and rare motor neuropathies, both of which are potentially reversible (Stockler 2011). Neuropathies have also been described with chronic administration of doses as low as 50 mg/day; however, some patients do not experience neuropathy (at low or high doses), even after years of administration (McLachlan 1995; Stockler 2011).
None known.
Altretamine: Pyridoxine may diminish the therapeutic effect of Altretamine. Specifically when altretamine is used in combination with Cisplatin the response duration may be diminished. Management: Consider avoiding concomitant use of pyridoxine in a altretamine/cisplatin regimen. Although pyridoxine may have beneficial effects on altretamine-associated neurotoxicity, it may reduce the duration of response to altretamine. Risk D: Consider therapy modification
Fosphenytoin: Pyridoxine may increase the metabolism of Fosphenytoin. This is most apparent in high pyridoxine doses (e.g., 80 mg to 200 mg daily) Risk C: Monitor therapy
Levodopa-Containing Products: Pyridoxine may diminish the therapeutic effect of Levodopa-Containing Products. Management: The concomitant use of pyridoxine and levodopa (in the absence of a dopa decarboxylase inhibitor (DDI)) should be avoided. Use of a DDI (eg, carbidopa) with levodopa will essentially eliminate the risk of this interaction. Risk D: Consider therapy modification
PHENobarbital: Pyridoxine may decrease the serum concentration of PHENobarbital. Risk C: Monitor therapy
Phenytoin: Pyridoxine may increase the metabolism of Phenytoin. This is most apparent in high pyridoxine doses (e.g., 80 mg to 200 mg daily) Risk C: Monitor therapy
Primidone: Pyridoxine may decrease serum concentrations of the active metabolite(s) of Primidone. Specifically, concentrations of phenobarbital may be reduced. Risk C: Monitor therapy
Water soluble vitamins cross the placenta (IOM 1998).
Maternal pyridoxine plasma concentrations may decrease as pregnancy progresses and requirements may be increased in pregnant women (IOM 1998).
Pyridoxine is used to treat nausea and vomiting of pregnancy (ACOG 2018; Neibyl 2010; SOGC [Campbell 2016]). Pyridoxine is also recommended for the prevention of peripheral neuropathy associated with isoniazid therapy in pregnant patients treated for Mycobacterium tuberculosis (ATS/CDC/IDSA [Nahid 2016]).
Pyridoxine is present in breast milk (IOM 1998).
Breast milk concentrations vary by maternal intake. Pyridoxine requirements are increased in breastfeeding women compared to nonbreastfeeding women (IOM 1998). Possible inhibition of lactation at doses >600 mg/day when taken immediately postpartum (Foukas 1973). Although the manufacturer recommends that caution be exercised when administering pyridoxine injection to breastfeeding women; pyridoxine is considered compatible with breastfeeding (WHO 2002). Pyridoxine is recommended for the prevention of peripheral neuropathy associated with isoniazid therapy in breastfeeding patients treated for Mycobacterium tuberculosis (ATS/CDC/IDSA [Nahid 2016]).
Dietary adequate Intake (AI) (IOM 1998):
1 to 6 months: 0.1 mg/day
7 to 12 months: 0.3 mg/day
Dietary recommended daily allowance (RDA) (IOM 1998):
1 to 3 years: 0.5 mg
4 to 8 years: 0.6 mg
9 to 13 years: 1 mg
14 to 18 years: Females: 1.2 mg; Males: 1.3 mg
19 to 50 years: 1.3 mg
≥51 years: Females: 1.5 mg; Males: 1.7 mg
Pregnancy: 1.9 mg
Lactation: 2 mg
For treatment of isoniazid or gyromitrin-containing mushroom toxicity: Anion gap, arterial blood gases, electrolytes, neurological exam, seizure activity
Over 50 ng/mL (SI: 243 nmol/L) (varies considerably with method). A broad range is ~25-80 ng/mL (SI: 122-389 nmol/L). HPLC method for pyridoxal phosphate has normal range of 3.5-18 ng/mL (SI: 17-88 nmol/L).
Precursor to pyridoxal, which functions in the metabolism of proteins, carbohydrates, and fats; pyridoxal also aids in the release of liver and muscle-stored glycogen and in the synthesis of GABA (within the central nervous system) and heme
When used for the treatment of ethylene glycol poisoning, pyridoxine is theorized to increase the formation of glycine, a nontoxic metabolite (Barceloux 1999).
Absorption: Oral: Well absorbed (IOM 1998)
Metabolism: Hepatic to pyridoxal phosphate and pyridoxamine phosphate (active forms)
Half-life elimination: Biologic: 15 to 20 days
Excretion: Urine (as metabolites)
Solution (Pyridoxine HCl Injection)
100 mg/mL (per mL): $19.88
Tablets (Pyridoxine HCl Oral)
25 mg (per each): $0.01
50 mg (per each): $0.08
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