Triamterene

**Semantic type:** Pharmacologic Substance

**Definition:** A pteridine derivative with potassium-sparing diuretic property. Triamterene blocks the sodium-potassium exchange pump (Na-K-ATPase) in the luminal membrane of principal cells in the late distal tubule, cortical collecting tubule and collecting duct in the kidney. This reversible inhibition of the electrogenic sodium transport decreases the lumen-negative transepithelial potential difference and thus reduces the driving force for K+ movement into the tubular lumen resulting in the inhibition of sodium reabsorption in exchange for K+ and H+.

**Synonyms:** - 6-Phenyl-2,4,7-pteridinetriamine - 6-Phenyl-2,4,7-triaminopteridine - Dyrenium - TRIAMTERENE