Potassium Supplementation in Hypertensive Patients with Diuretic-Induced Hypokalemia

TLDR

Potassium balance changes affect blood pressure, with potassium supplements reported to lower blood pressure in normokalemic hypertensive patients. The study evaluated whether potassium chloride supplementation reduces blood pressure in hypertensive patients with diuretic‑induced hypokalemia through a randomized, double‑blind, crossover trial. Participants were selected based on serum potassium below 3.5 mmol/L and received 60 mmol/day potassium chloride or placebo for six weeks while maintaining their diuretic dose. Potassium repletion raised serum potassium by 0.56 mmol/L and lowered mean blood pressure by 5.5 mm Hg, with a 4 mm Hg drop in 9 of 16 patients, and the blood‑pressure reduction correlated with decreased plasma renin activity but not with aldosterone changes. N Engl J Med 1985; 312:746–9.

Abstract

Changes in potassium balance have been found to have variable effects on the blood pressure of animals, and the administration of potassium supplements has been reported to lower the blood pressure of normokalemic hypertensive patients. To assess the effect of potassium repletion in hypokalemic hypertension, we administered either potassium chloride, 60 mmol per day, or placebo tablets, each for six weeks, in a randomized, double-blind, crossover trial to 16 hypertensive patients who had diuretic-induced hypokalemia and who continued to take a constant amount of diuretic. We selected patients whose control serum potassium levels were below 3.5 mmol per liter. In association with an average rise in the serum potassium concentration of 0.56 mmol per liter, the mean blood pressure fell by an average of 5.5 mm Hg (P = 0.004), with at least a 4 mm Hg fall observed in 9 of the 16 patients. The fall in blood pressure correlated with a fall in plasma renin activity (r = 0.568, P = 0.043) but not with changes in plasma aldosterone levels or other variables. We conclude that short-term potassium supplementation that ameliorates diuretic-induced hypokalemia may induce a significant fall in blood pressure. (N Engl J Med 1985; 312:746–9.)