triamteren

Triamterene (also spelled triamteren in some languages) is a potassium-sparing diuretic used to treat edema and hypertension. It acts on the late distal tubule and collecting duct of the nephron by inhibiting the epithelial sodium channel (ENaC), reducing sodium reabsorption and water excretion while preserving potassium.

Clinical uses include edema associated with congestive heart failure, liver cirrhosis, and nephrotic syndrome, as well as hypertension. It is commonly prescribed in fixed-dose combinations with a thiazide-type diuretic, most often hydrochlorothiazide, to enhance diuresis while limiting potassium loss.

Adverse effects center on the risk of hyperkalemia, which can lead to muscle weakness or cardiovascular issues. Other possible effects include nausea, vomiting, dizziness, kidney stones, rash, and photosensitivity. Cautions include impaired renal function or anuria, and the potential for dangerous elevations in potassium when combined with other potassium-sparing agents, potassium supplements, ACE inhibitors, ARBs, or NSAIDs.

Triamterene is taken orally and typically begins to produce diuresis within a few hours; the effects are relatively short-lived and the drug is largely excreted in the urine. It is sold alone under brand names such as Dyrenium and in combination products with hydrochlorothiazide (for example, Dyazide, Maxzide) in many markets.