Effects of verapamil and trandolapril in the treatment of hypertension. Trandolapril Study Group.

The combination of an angiotensin converting enzyme inhibitor with a calcium antagonist has become a common way of treating patients with essential hypertension who respond insufficiently to monotherapy. This double-blind, randomized, parallel, placebo-controlled, multicenter, outpatient study evaluated the antihypertensive efficacy and safety of a calcium antagonist (verapamil SR) and an angiotensin converting enzyme inhibitor (trandolapril) in patients with mild-to-moderate (stages I and II) essential hypertension. Six hundred thirty-one patients were enrolled in this 10-week study. After a 4-week single-blind placebo phase, patients received one of the following daily dosage regimens in a double-blind fashion for 6 weeks: placebo, 4 mg of trandolapril, 240 mg of verapamil SR, or a combination of 4 mg of trandolapril and 240 mg of verapamil SR. Trough sitting diastolic blood pressure was lowered by 4.5 mm Hg, 4.3 mm Hg, and 8.1 mm Hg more than placebo in the trandolapril, verapamil SR, and combination groups, respectively. In the combination group, sitting diastolic blood pressure was significantly lowered (P < .01) by 3.6 mm Hg more than in the trandolapril group and by 3.8 mm Hg more than in the verapamil SR group. An analysis of the trough-to-peak ratio for sitting diastolic blood pressure revealed values of 0.75 and 0.67, for the 4-mg trandolapril and the combination groups, respectively, at end point. The overall incidence of adverse reactions was similar for all treatment groups. In this study the combination of an angiotensin converting enzyme inhibitor and calcium antagonist was well tolerated and more effective than either agent administered alone for the treatment of mild-to-moderate essential hypertension.