Pharmacology General 0eec8c9a The primary site of action of triameterene and spironolactone is the - A Proximal tubule B Distal tubule C Ascending Loop of Henle D Descending Loop of Henle High-Yield Explanation Ans. is 'b' i.e., Distal tubule o Potassium sparing diuretics (Sprionolactone and triameterene) act on late distal tubule and collecting duct.