Abstract

Spironolactone (Aldactone-A),¹ triamterene (Dytac)^{2 3} and amiloride (Midamor)² are all potassium-sparing diuretics which we have reviewed separately. Spironolactone is a steroid which competitively antagonises aldosterone in the distal renal tubule; triamterene and amiloride directly affect electrolyte transport in the distal tubule without antagonising aldo-sterone. However, the ultimate effects of these drugs are quite similar, and it is not clear whether they should be regarded as interchangeable or whether their uses should differ.