triamterene

Triamterene is a potassium-sparing diuretic used to help remove excess fluid while minimizing potassium loss. It belongs to the nonsteroidal class of diuretics and acts on the distal nephron, primarily by blocking epithelial sodium channels in the collecting ducts. This reduces sodium reabsorption and potassium excretion, producing a modest diuretic effect with preserved or increased potassium levels.

In clinical practice, tri­amterene is often prescribed alone for edema or in combination with a thiazide-type diuretic (for example, in products such as triamterene/hydrochlorothiazide) to enhance diuresis while limiting potassium loss. Brand names include Dyrenium for the single-agent form, and combination products such as Maxzide or Dyazide.

Indications generally include management of edema associated with heart failure, liver cirrhosis, or nephrotic syndrome, and hypertension when used as part of a combination regimen. Dosing and duration depend on the condition being treated and patient response.

Common adverse effects include hyperkalemia, which can be serious in people with kidney impairment, dehydration, or concomitant use of other potassium-raising medications. Other potential effects are kidney stone formation due to crystal formation in the urine, and rare hematologic or allergic reactions. Contraindications include anuria and significant renal impairment, hyperkalemia, and hypersensitivity to the drug. Caution is advised during pregnancy and lactation. Drug interactions include concurrent potassium-sparing agents, ACE inhibitors or ARBs, NSAIDs, and potassium supplements, all of which can raise potassium levels.