Efficacy and tolerance of trandolapril (0.5-2 mg) administered for 4 weeks in patients with mild-to-moderate hypertension. Investigator Study Group.

: This double-blind, placebo-controlled, dose-ranging study recruited 170 patients with mild-to-moderate hypertension from nine centers. After a 4-week, single-blind, placebo run-in phase, patients were randomized in a double-blind fashion to four parallel groups that received either placebo or 0.5, 1, or 2 mg trandolapril for 4 weeks. Treatment was administered as a once-daily dose in the morning and blood pressure was measured 24 h after drug intake. The primary criterion of efficacy was a decrease in supine diastolic blood pressure. At the end of the study, the lowest dose of trandolapril that consistently produced a significant difference from placebo in reducing blood pressure was 1 mg (-6.6 mm Hg for supine diastolic blood pressure). It was effective from around 2 weeks onward; the 2-mg dose differed significantly from placebo from around 1 week onward. At the end of the study, the 1- and 2-mg doses were equally effective. The lowest dose tested, 0.5 mg, showed some evidence of an effect on systolic blood pressure and may well prove to be a useful dose in patients who are highly sensitive to the effect of ACE inhibition. Tolerance throughout the study was good for all doses tested.