Abnormal elevation of serum potassium levels (at least 5.5 mEq/L) can occur with all potassium-sparing agents, including triamterene. Hyperkalemia is more likely to occur in patients with renal impairment and diabetes (even without evidence of renal impairment), and in elderly or severely ill patients. Because uncorrected hyperkalemia may be fatal, serum potassium levels must be monitored at frequent intervals especially in patients receiving triamterene, when dosages are changed, or with any illness that may influence renal function.
Edema: Oral: Initial: 100 mg twice daily; titrate as need based on patient response; maximum: 300 mg/day
Hypertension (off-label use) (alternative agent): Oral: 50 to 100 mg/day in 1 or 2 divided doses (ACC/AHA [Whelton 2017]). Note: Typically used as combination therapy with thiazide diuretics to prevent hypokalemia; minimal antihypertensive effect as monotherapy.
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
Manufacturer's labeling:
Mild to moderate impairment: There are no dosage adjustments provided in the manufacturer's labeling.
Severe impairment, progressive kidney disease, or anuria: Use is contraindicated.
Alternate recommendations: CrCl ≤50 mL/minute: Avoid use (Aronoff 2007). The Beers Criteria recommends avoiding use in older adults ≥65 years of age with a CrCl <30 mL/minute due to the risk of hyperkalemia and hyponatremia (Beers Criteria [AGS 2019]).
Mild to moderate impairment: There are no dosage adjustments provided in the manufacturer's labeling (has not been studied).
Severe impairment: Use is contraindicated.
(For additional information see "Triamterene: Pediatric drug information")
Edema: Children and Adolescents: Limited data available: Oral: 1 to 4 mg/kg/day divided into 1 to 2 doses; maximum daily dose: 6 mg/kg/day or 300 mg/day, whichever is lower (Gal 2007; van der Vorst 2006)
Hypertension: Limited data available: Children and Adolescents: Oral: Initial: 0.5 to 1 mg/kg/dose twice daily; maximum daily dose: 3 to 4 mg/kg/day or 300 mg/day, whichever is lower (NHLBI 2004; NHLBI 2011)
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
Mild to moderate impairment: There are no dosage adjustments provided in the manufacturer's labeling; use with caution, monitor serum potassium.
Severe impairment or progressive kidney disease: Use is contraindicated.
Mild to moderate impairment: There are no dosage adjustments provided in the manufacturer's labeling.
Severe hepatic disease: Use is contraindicated.
Refer to adult dosing. In the management of hypertension, consider lower initial doses and titrate to response (Aronow 2011).
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Capsule, Oral:
Dyrenium: 50 mg, 100 mg [contains fd&c yellow #6 (sunset yellow)]
Generic: 50 mg, 100 mg
Yes
Oral: Administer after meals.
Oral: Administer with food to avoid GI upset
Edema: Treatment of edema associated with congestive heart failure, cirrhosis of the liver and the nephrotic syndrome; also in steroid-induced edema, idiopathic edema and edema due to secondary hyperaldosteronism.
Hypertension (alternative agent)
Triamterene may be confused with trimipramine
Dyrenium may be confused with Pyridium
Beers Criteria: Diuretics are identified in the Beers Criteria as potentially inappropriate medications to be used with caution in patients 65 years and older due to the potential to cause or exacerbate syndrome of inappropriate antidiuretic hormone secretion (SIADH) or hyponatremia; monitor sodium concentration closely when initiating or adjusting the dose in older adults (Beers Criteria [AGS 2019]).
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified. Frequency not defined.
Central nervous system: Dizziness, fatigue, headache
Dermatologic: Skin photosensitivity, skin rash
Endocrine & metabolic: Hyperkalemia, hypokalemia, increased uric acid, metabolic acidosis
Gastrointestinal: Diarrhea, nausea, vomiting, xerostomia
Genitourinary: Azotemia
Hematologic & oncologic: Hematologic abnormality, megaloblastic anemia, thrombocytopenia
Hepatic: Jaundice, liver enzyme disorder
Hypersensitivity: Anaphylaxis
Neuromuscular & skeletal: Weakness
Renal: Acute interstitial nephritis (rare), acute renal failure (rare), increased blood urea nitrogen, increased serum creatinine, nephrolithiasis
Hypersensitivity to triamterene or any component of the formulation; anuria; severe or progressive kidney disease or dysfunction with the possible exception of nephrosis; severe hepatic disease; hyperkalemia; coadministration with other potassium-sparing agents or other formulations containing triamterene
Concerns related to adverse effects:
• Fluid/electrolyte loss: Triamterene can lead to profound diuresis with fluid and electrolyte loss; close medical supervision and dose evaluation are required. Patients with heart failure, renal disease, or cirrhosis may be particularly susceptible to fluid and electrolyte abnormalities. Watch for and correct electrolyte disturbances; adjust dose to avoid dehydration.
• Hyperkalemia: [US Boxed Warning]: Hyperkalemia can occur; patients at risk include those with renal impairment, diabetes, the elderly, and the severely ill. Serum potassium levels must be monitored at frequent intervals especially when dosages are changed or with any illness that may cause renal dysfunction. . In patients who develop hyperkalemia or if hyperkalemia is suspected, obtain an electrocardiogram to rule out hyperkalemia-induced QRS prolongation or other cardiac arrhythmias. Discontinue triamterene and any potassium supplementation in patients who develop hyperkalemia; treat cardiac arrhythmias as clinically indicated.
• Hypersensitivity reactions: Isolated occurrences have been reported. Observe for blood dyscrasias, liver damage or idiosyncratic reactions
• Photosensitivity: Can cause photosensitivity.
Disease-related concerns:
• Adrenal insufficiency: Avoid use of diuretics for treatment of elevated blood pressure in patients with primary adrenal insufficiency (Addison disease). Adjustment of glucocorticoid/mineralocorticoid therapy and/or use of other antihypertensive agents is preferred to treat hypertension (Bornstein 2016; Inder 2015).
• Diabetes: Use with caution in patients with prediabetes or diabetes mellitus; may increase blood glucose concentrations and necessitate dosage adjustment of hypoglycemic agents.
• Gout: May cause elevation in uric acid.
• Hepatic impairment: Use with caution in patients with severe hepatic dysfunction; in cirrhosis, avoid electrolyte and acid/base imbalances that might lead to hepatic encephalopathy.
• Kidney stones: Use with caution in patients with kidney stones.
Other warnings/precautions:
• Abrupt discontinuation: In patients who have received triamterene for prolonged periods of time, a hypothetical risk of rebound kaliuresis may occur when abruptly discontinued; withdraw triamterene gradually in these patients.
None known.
Alfuzosin: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Amifostine: Blood Pressure Lowering Agents may enhance the hypotensive effect of Amifostine. Management: When used at chemotherapy doses, hold blood pressure lowering medications for 24 hours before amifostine administration. If blood pressure lowering therapy cannot be held, do not administer amifostine. Use caution with radiotherapy doses of amifostine. Risk D: Consider therapy modification
Ammonium Chloride: Potassium-Sparing Diuretics may enhance the adverse/toxic effect of Ammonium Chloride. Specifically the risk of systemic acidosis. Risk C: Monitor therapy
Amphetamines: May diminish the antihypertensive effect of Antihypertensive Agents. Risk C: Monitor therapy
Angiotensin II Receptor Blockers: May enhance the hyperkalemic effect of Potassium-Sparing Diuretics. Risk C: Monitor therapy
Angiotensin-Converting Enzyme Inhibitors: Potassium-Sparing Diuretics may enhance the hyperkalemic effect of Angiotensin-Converting Enzyme Inhibitors. Risk C: Monitor therapy
Antipsychotic Agents (Second Generation [Atypical]): Blood Pressure Lowering Agents may enhance the hypotensive effect of Antipsychotic Agents (Second Generation [Atypical]). Risk C: Monitor therapy
Barbiturates: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Benperidol: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Brigatinib: May diminish the antihypertensive effect of Antihypertensive Agents. Brigatinib may enhance the bradycardic effect of Antihypertensive Agents. Risk C: Monitor therapy
Brimonidine (Topical): May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Bromperidol: May diminish the hypotensive effect of Blood Pressure Lowering Agents. Blood Pressure Lowering Agents may enhance the hypotensive effect of Bromperidol. Risk X: Avoid combination
Cardiac Glycosides: Potassium-Sparing Diuretics may diminish the therapeutic effect of Cardiac Glycosides. In particular, the inotropic effects of digoxin appear to be diminished. Potassium-Sparing Diuretics may increase the serum concentration of Cardiac Glycosides. This particular effect may be unique to Spironolactone. Risk C: Monitor therapy
CycloSPORINE (Systemic): Potassium-Sparing Diuretics may enhance the hyperkalemic effect of CycloSPORINE (Systemic). Risk X: Avoid combination
Desmopressin: Hyponatremia-Associated Agents may enhance the hyponatremic effect of Desmopressin. Risk C: Monitor therapy
Dexmethylphenidate: May diminish the therapeutic effect of Antihypertensive Agents. Risk C: Monitor therapy
Diacerein: May enhance the therapeutic effect of Diuretics. Specifically, the risk for dehydration or hypokalemia may be increased. Risk C: Monitor therapy
Diazoxide: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Dofetilide: Triamterene may increase the serum concentration of Dofetilide. Risk C: Monitor therapy
Drospirenone-Containing Products: May enhance the hyperkalemic effect of Potassium-Sparing Diuretics. Risk C: Monitor therapy
DULoxetine: Blood Pressure Lowering Agents may enhance the hypotensive effect of DULoxetine. Risk C: Monitor therapy
Eplerenone: May enhance the hyperkalemic effect of Potassium-Sparing Diuretics. Management: This combination is contraindicated in patients receiving eplerenone for treatment of hypertension. Potassium supplements may be needed to treat/prevent hypokalemia in selected patients with heart failure receiving eplerenone and high dose loop diuretics. Risk D: Consider therapy modification
Finerenone: Potassium-Sparing Diuretics may enhance the hyperkalemic effect of Finerenone. Risk C: Monitor therapy
Heparin: May enhance the hyperkalemic effect of Potassium-Sparing Diuretics. Management: Monitor serum potassium concentrations closely. The spironolactone Canadian product monograph lists its combination with heparin or low molecular weight heparins as contraindicated. Risk C: Monitor therapy
Heparins (Low Molecular Weight): May enhance the hyperkalemic effect of Potassium-Sparing Diuretics. Management: Monitor serum potassium concentrations closely. The spironolactone Canadian product monograph lists its combination with heparin or low molecular weight heparins as contraindicated. Risk C: Monitor therapy
Herbal Products with Blood Pressure Increasing Effects: May diminish the antihypertensive effect of Antihypertensive Agents. Risk C: Monitor therapy
Herbal Products with Blood Pressure Lowering Effects: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Hypotension-Associated Agents: Blood Pressure Lowering Agents may enhance the hypotensive effect of Hypotension-Associated Agents. Risk C: Monitor therapy
Indomethacin: May enhance the nephrotoxic effect of Triamterene. Management: Consider alternatives to concomitant treatment with triamterene and indomethacin. If the combination cannot be avoided, monitor for development of renal failure. Risk D: Consider therapy modification
Levodopa-Containing Products: Blood Pressure Lowering Agents may enhance the hypotensive effect of Levodopa-Containing Products. Risk C: Monitor therapy
Lormetazepam: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Methylphenidate: May diminish the antihypertensive effect of Antihypertensive Agents. Risk C: Monitor therapy
Molsidomine: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Naftopidil: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Nicergoline: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Nicorandil: May enhance the hyperkalemic effect of Potassium-Sparing Diuretics. Risk C: Monitor therapy
Nicorandil: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Nitroprusside: Blood Pressure Lowering Agents may enhance the hypotensive effect of Nitroprusside. Risk C: Monitor therapy
Nonsteroidal Anti-Inflammatory Agents: May diminish the antihypertensive effect of Potassium-Sparing Diuretics. Nonsteroidal Anti-Inflammatory Agents may enhance the hyperkalemic effect of Potassium-Sparing Diuretics. Risk C: Monitor therapy
Obinutuzumab: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Management: Consider temporarily withholding blood pressure lowering medications beginning 12 hours prior to obinutuzumab infusion and continuing until 1 hour after the end of the infusion. Risk D: Consider therapy modification
Opioid Agonists: May enhance the adverse/toxic effect of Diuretics. Opioid Agonists may diminish the therapeutic effect of Diuretics. Risk C: Monitor therapy
Pentoxifylline: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Pholcodine: Blood Pressure Lowering Agents may enhance the hypotensive effect of Pholcodine. Risk C: Monitor therapy
Phosphodiesterase 5 Inhibitors: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Potassium Salts: May enhance the hyperkalemic effect of Potassium-Sparing Diuretics. Management: Avoid coadministration of a potassium-sparing diuretic and a potassium salt. This combination should only be used in cases of significant hypokalemia, and only if serum potassium can be closely monitored. Risk D: Consider therapy modification
Pramipexole: Triamterene may enhance the hypotensive effect of Pramipexole. Triamterene may increase the serum concentration of Pramipexole. Risk C: Monitor therapy
Prostacyclin Analogues: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Quinagolide: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
QuiNIDine: Potassium-Sparing Diuretics may diminish the therapeutic effect of QuiNIDine. Risk C: Monitor therapy
Sodium Phosphates: Diuretics may enhance the nephrotoxic effect of Sodium Phosphates. Specifically, the risk of acute phosphate nephropathy may be enhanced. Management: Consider avoiding this combination by temporarily suspending treatment with diuretics, or seeking alternatives to oral sodium phosphate bowel preparation. If the combination cannot be avoided, hydrate adequately and monitor fluid and renal status. Risk D: Consider therapy modification
Spironolactone: Triamterene may enhance the hyperkalemic effect of Spironolactone. Risk X: Avoid combination
Tacrolimus (Systemic): Potassium-Sparing Diuretics may enhance the hyperkalemic effect of Tacrolimus (Systemic). Risk C: Monitor therapy
Tolvaptan: May enhance the hyperkalemic effect of Potassium-Sparing Diuretics. Risk C: Monitor therapy
Triamterene crosses the placenta and is found in cord blood. Use of triamterene to treat edema during normal pregnancies is not appropriate; use may be considered when edema is due to pathologic causes (as in the nonpregnant patient); monitor.
It is not known if triamterene is present in breast milk. Breastfeeding is not recommended by the manufacturer.
Blood pressure; serum electrolytes (especially potassium), renal function; weight, I & O
Hypertension: The 2017 Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults (ACC/AHA [Whelton 2017]):
Confirmed hypertension and known CVD or 10-year ASCVD risk ≥10%: Target blood pressure <130/80 mm Hg is recommended
Confirmed hypertension without markers of increased ASCVD risk: Target blood pressure <130/80 mm Hg may be reasonable
Blocks epithelial sodium channels in the late distal convoluted tubule (DCT) and collecting duct which inhibits sodium reabsorption from the lumen. This effectively reduces intracellular sodium, decreasing the function of Na+/K+ ATPase, leading to potassium retention and decreased calcium, magnesium, and hydrogen excretion. As sodium uptake capacity in the DCT/collecting duct is limited, the natriuretic, diuretic, and antihypertensive effects are generally considered weak.
Onset of action: Diuresis: 2 to 4 hours; Note: Maximum therapeutic effect may not occur until after several days of therapy
Duration: Diuresis: 7 to 9 hours
Absorption: Rapid
Metabolism: Primarily metabolized to the sulfate conjugate of hydroxytriamterene
Time to peak, plasma: ~3 hours
Excretion: Urine (21% to <50%; primarily as metabolites)
Capsules (Dyrenium Oral)
50 mg (per each): $14.58
100 mg (per each): $14.58
Capsules (Triamterene Oral)
50 mg (per each): $11.93 - $11.94
100 mg (per each): $11.93 - $11.94
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