Quinapril: a double-blind, placebo-controlled trial in essential hypertension.

Quinapril HCl is a novel, nonsulfhydryl angiotensin-converting enzyme (ACE) inhibitor. The Study Group evaluated its efficacy (20, 40, 80 mg daily with forced dose titration determination at trough blood pressure) once daily versus twice daily versus placebo, as well as its tolerability and safety, in 270 patients with mild to moderate essential hypertension (WHO Stages I and II, sitting diastolic blood pressure [DPB] greater than or equal to 95 mm Hg), for twelve weeks. Reductions in DBP of up to 13 mm Hg were obtained, and in full dosage more than 65% of patients achieved a reduction in DBP of 10 mm Hg or more from baseline or reduced their DBP to 90 mm Hg or less. Quinapril was well tolerated, and reported adverse effects were scarcely more frequent than in the placebo group. Once daily doses of quinapril were as safe and effective as twice-daily doses. Quinapril is likely to exhibit good therapeutic utility in the management of essential hypertension.