Efficacy of an antihypertensive agent. Comparison of methyldopa and hydrochlorothiazide in combination and singly.

In a double-blind evaluation, the efficacy of a combination of methyldopa with hydrochlorothiazide was compared with that of its components, methyldopa and hydrochlorothiazide. The combination was found to be more efficacious than either of its components. It reduced the arithmetic mean of the pressures of all patients from 170/116 to 133/95 mm Hg in four weeks. Despite the greater effect of the combination, side effects were mild.