Effects of benazepril on stress testing blood pressure in essential hypertension

Abstract

The effects of different doses of the angiotensinconverting enzyme inhibitor benazepril on cardiovascular response to a set of standardized laboratory tasks were analyzed. Eighteen patients (15 men and 3 women) with mild-to-moderate essential hypertension were randomly allocated to receive 10 or 20 mg of benazepril, or placebo, each administered once daily for 2 weeks, according to a double-blind, 3-period design. At the end of each treatment period, patients were examined at resting baseline and while performing mental arithmetic, handgrip and cycle ergometry tests. In comparison with placebo, the average reductions in resting systolic blood pressure (BP) were 8.7 mm Hg (95% confidence intervals [CI] −15.2 to −2.1) with 10 mg of benazepril, and 7.8 mm Hg (95% CI −14.4 to −1.3) with 20 mg; the corresponding reductions in resting diastolic BP were 5.1 mm Hg (95% CI −8.7 to −1.4) and 6.8 mm Hg (95% CI −10.4 to −3.1) (all p < 0.05). During mental arithmetic, the reductions in systolic BP were 10.4 mm Hg (95% CI −17.4 to −3.4) with 10 mg of benazepril, and 13.8 mm Hg (95% CI −20.8 to −6.8) with 20 mg; diastolic BP was reduced by 4.5 mm Hg (95% CI −8.5 to −0.5) and 8.3 mm Hg (95% CI −13.2 to −4.3), respectively (all p < 0.05). During the handgrip test, systolic and diastolic BP were significantly reduced after 20 mg of benazepril by 10.8 mm Hg (95% CI −20.6 to −1) and 6.9 mm Hg (95% CI −12.7 to −1.1.), respectively (both p < 0.05); the reductions in systolic and diastolic BP observed after 10 mg of benazepril did not achieve statistical significance (9.2 mm Hg [95% CI −19.1 to 0.6] and 2.1 mm Hg [95% CI −7.9 to 3.7], respectively; both p > 0.05). During ergometry, no active treatment significantly affected systolic and diastolic BP values (all p > 0.05). During mental arithmetic and the handgrip test, there was no treatment effect on the magnitude of BP reactivity from baseline (all p > 0.05); during ergometry, systolic BP reactivity was higher after both benazepril doses than after placebo (both p < 0.05). The data suggest that benazepril, especially at higher doses, may be effective in reducing BP not only at rest, but also during some commonly recurring stressful situations.