Diuretic regimens in essential hypertension. A comparison of hypokalemic effects, BP control, and cost.

Intolerable side effects and hypokalemia during thiazide treatment of hypertension frequently necessitate a change in diuretic regimen. The hypokalemic effects, effectiveness in controlling BP, and cost of several alternate diuretic regimens were evaluated. Prevalences of serum K+ values less than 3.5 mEq/L were as follows for the various regimens: hydrochlorothiazide, 50 mg daily, 11.0% (n = 500); chlorthalidone, 25 mg daily, 8.1% (n = 37); triamterene, 100 mg, plus hydrochlorothiazide, 50 mg daily, 5.3% (n = 357); hydrochlorothiazide, 25 mg daily, 2.2% (n = 183); and furosemide, 40 mg daily, 3.5% (n = 284). In paired studies comparing hydrochlorothiazide with alternate diuretic regimens, potassium conservation was comparable with furosemide, the triamterene/hydrochlorothiazide combination, the spironolactone/hydrochlorothiazide combination, and adding potassium, 37 mEq daily. All alternate diuretic regimens were as effective as hydrochlorothiazide in controlling BP. Furosemide reduced serum glucose and calcium levels compared with hydrochlorothiazide. When these factors and costs are considered, furosemide appears to be the most cost-effective alternative in patients with hypertension in whom intolerable side effects or hypokalemia develops while taking hydrochlorothiazide.