Response of thiazide-induced hypokalemia to amiloride

Abstract

The effects of amiloride hydrochloride on thiazide-induced hypokalemia were evaluated. In metabolic balance studies, amiloride reversed thiazide-induced urinary K+ loss, restored plasma bicarbonate concentration and pH to pretreatment levels, and produced further increases in aldosterone secretion. Effects of long-term administration of hydrochlorothiazide and an amiloride-hydrochlorothiazide combination were compared in outpatients who had experienced thiazide-induced hypokalemia while receiving oral K+ supplements. After 8 wk, those given hydrochlorothiazide alone had an average serum K+ level of 3.01 .+-. 0.10 meq/l, significantly lower than the control level (3.75 .+-. 0.08 meq/l). Those given the amiloride-hydrochlorothiazide combination had an average serum K+ level of 3.75 .+-. 0.08 meq/l, not significantly different from the control value (3.82 .+-. 0.08 meq/l). Both groups had increased plasma aldosterone concentrations and plasma renin activity. The K+-conserving effect of amiloride persisted with extended therapy.