[Tablet strength and dosage of thiazides in hypertension must be reduced].
A number of studies indicate that hydrochlorothiazide doses above 50 mg daily provide little additional hypotensive effect but progressively greater hypokalemic effect. From these and similar studies on other thiazides a daily dose range for thiazides of 12.5-50 mg for hydrochlorothiazide, 1.25-5 mg for bendroflumethiazide, 1-2 mg for trichloromethiazide, 0.5-1 mg for polythiazide, and 6.25-25 mg for chlorthalidone appears to be sufficient. Because amiloride enhances the natriuretic effect of thiazides, this agent has not only a Mg2+/K(+)-sparkling effect, but also a potential thiazide-sparing effect. For this reason, the recommended doses of fixed combinations of hydrochlorothiazide and amiloride should be lowered to the range 6.25 mg/0.625 mg--25 mg/2.5 mg.