The Sound of Evolution
Triamterene
Mechanism of action:
Triamterene is a potassium-sparing diuretic and an epithelial sodium channel inhibitor. It directly blocks epithelial sodium channels (ENaC) on the membrane of renal tubular principal cells, preventing sodium ions from being reabsorbed from the tubular lumen into the cell. Under normal conditions, sodium entry into the cell creates a negative luminal potential that promotes the secretion of potassium and hydrogen ions. When sodium reabsorption declines, the negative luminal potential is reduced, and the secretion of potassium and hydrogen ions correspondingly decreases.
Reference(s):
1. Gilfrich HJ et al. (1983). Pharmacokinetics of triamterene after i.v. administration to man: determination of bioavailability. Eur J Clin Pharmacol.
2. Baba WI et al. (1962). Triamterene, a new diuretic drug. I. Studies in normal men and in adrenalectomized rats. Br Med J.
3. Knauf H et al. (1976). On the mechanism of action of triamterene: effects on transport of Na+, K+, and H+/HCO3- -ions. Eur J Clin Invest.