Diltiazem for treatment of essential hypertension: a double-blind controlled study with reserpine

In a double-blind, parallel, 12-week trial, antihypertensive effects of diltiazem and reserpine were compared in 107 patients with essential hypertension. Diltiazem reduced blood pressure from 176/100 mmHg to 154/86 mmHg after 12 weeks, and reserpine reduced blood pressure from 171/96 mmHg to 155/85 mmHg. The difference between diltiazem and reserpine was not statistically significant. However, among a subset of patients given 180 mg/day of diltiazem, a significantly better antihypertensive effect was achieved than among a subset given 0.3 mg of reserpine. The incidence of side effects and complications in the diltiazem group was about one half that in the reserpine group (12.3% and 27.1%, respectively). Side effects of diltiazem were mild, and the drug was extremely well tolerated. These results show that diltiazem is an effective antihypertensive drug for the treatment of mild to moderate essential hypertension.