Triamterene
Triamterene Prescribing Information
Triamterene Capsules are indicated in the treatment of edema associated with congestive heart failure, cirrhosis of the liver and the nephrotic syndrome; steroid-induced edema, idiopathic edema and edema due to secondary hyperaldosteronism.
Triamterene Capsules may be used alone or with other diuretics, either for its added diuretic effect or its potassium-sparing potential. It also promotes increased diuresis when patients prove resistant or only partially responsive to thiazides or other diuretics because of secondary hyperaldosteronism.
Edema during pregnancy may arise from pathological causes or from the physiologic and mechanical consequences of pregnancy. Diuretics are indicated in pregnancy (however, see
Dosage should be titrated to the needs of the individual patient. When used alone, the usual starting dose is 100 mg twice daily after meals. When combined with another diuretic or antihypertensive agent, the total daily dosage of each agent should usually be lowered initially and then adjusted to the patient’s needs. The total daily dosage should not exceed 300 mg. Please refer to PRECAUTIONS−General.
When triamterene capsules are added to other diuretic therapy or when patients are switched to triamterene capsules from other diuretics, all potassium supplementation should be discontinued.
Anuria. Severe or progressive kidney disease or dysfunction, with the possible exception of nephrosis. Severe hepatic disease. Hypersensitivity to the drug or any of its components.
Triamterene Capsules should not be used in patients with pre-existing elevated serum potassium, as is sometimes seen in patients with impaired renal function or azotemia, or in patients who develop hyperkalemia while on the drug. Patients should not be placed on dietary potassium supplements, potassium salts or potassium-containing salt substitutes in conjunction with triamterene.
Triamterene Capsules should not be given to patients receiving other potassium-sparing agents, such as spironolactone, amiloride hydrochloride, or other formulations containing triamterene. Two deaths have been reported in patients receiving concomitant spironolactone and triamterene or Dyazide®. Although dosage recommendations were exceeded in one case and in the other serum electrolytes were not properly monitored, these two drugs should not be given concomitantly.
Adverse effects are listed in decreasing order of frequency; however, the most serious adverse effects are listed first, regardless of frequency. All adverse effects occur rarely (that is, 1 in 1000, or less).
Hypersensitivity: anaphylaxis, rash, photosensitivity.
Metabolic: hyperkalemia, hypokalemia.
Renal: azotemia, elevated BUN and creatinine, renal stones, acute interstitial nephritis (rare), acute renal failure (one case of irreversible renal failure has been reported).
Gastrointestinal: jaundice and/or liver enzyme abnormalities, nausea and vomiting, diarrhea.
Hematologic: thrombocytopenia, megaloblastic anemia.
Central Nervous System: weakness, fatigue, dizziness, headache, dry mouth.
Caution should be used when lithium and diuretics are used concomitantly because diuretic-induced sodium loss may reduce the renal clearance of lithium and increase serum lithium levels with risk of lithium toxicity. Patients receiving such combined therapy should have serum lithium levels monitored closely and the lithium dosage adjusted if necessary.
A possible interaction resulting in acute renal failure has been reported in a few subjects when indomethacin, a nonsteroidal anti-inflammatory agent, was given with triamterene. Caution is advised in administering nonsteroidal anti-inflammatory agents with triamterene.
The effects of the following drugs may be potentiated when given together with triamterene: antihypertensive medication, other diuretics, preanesthetic and anesthetic agents, skeletal muscle relaxants (non-depolarizing).
Potassium-sparing agents should be used with caution in conjunction with angiotensin-converting enzyme (ACE) inhibitors due to an increased risk of hyperkalemia.
The following agents, given together with triamterene, may promote serum potassium accumulation and possibly result in hyperkalemia because of the potassium-sparing nature of triamterene, especially in patients with renal insufficiency: blood from blood bank (may contain up to 30 mEq of potassium per liter of plasma or up to 65 mEq per liter of whole blood when stored for more than 10 days); low-salt milk (may contain up to 60 mEq of potassium per liter); potassium-containing medications (such as parenteral penicillin G potassium); salt substitutes (most contain substantial amounts of potassium).
Triamterene may raise blood glucose levels; for adult-onset diabetes, dosage adjustments of hypoglycemic agents may be necessary during and/or after therapy; concurrent use with chlorpropamide may increase the risk of severe hyponatremia.
Triamterene Capsules are potassium-sparing diuretics
Triamterene is 6-Phenyl-2,4,7-triaminopteridine.
Its molecular weight is 253.26 (Rounded to 253.3). Triamterene is soluble in formic acid; sparingly soluble in methoxyethanol; very slightly soluble in acetic acid, alcohol and dilute mineral acid; practically insoluble in water, benzene, chloroform, ether and dilute alkali hydroxides.
50 mg: Beige Opaque color capsule imprinted with ‘E14’ on the body of the capsule filled with yellow colored granular powder.
100 mg: Beige Opaque color capsule imprinted with ‘E15’ on the body of the capsule filled with yellow colored granular powder.
Inactive ingredients consist of anhydrous lactose, gelatin, iron oxide red, iron oxide yellow, magnesium stearate, silicon dioxide, sodium lauryl sulfate and titanium dioxide.
FDA approved dissolution test specifications differ from USP.