This was a randomized double-blind parallel-group study of 283 patients who had mild-to-moderate [diastolic blood pressure (DBP) > 100 mmHg and < or = 115 mmHg]
hypertension. After a 3 (or 4)-week placebo wash-out period followed by 6 weeks of active treatment with
spirapril at either 3, 6, 12 or 24 mg once daily (or placebo), DBP decreased by approximately 10 mmHg in the (pooled)
spirapril-treated patients compared with approximately 5 mmHg with placebo. There were statistically significant differences between all active-treatment groups (except the 24-mg dose group) and placebo, but not among the
spirapril groups at the end of the +24-hour dosing interval. Reported adverse events were mostly not study
drug-related and were similar to those with placebo except for
headache, which was more frequent with
spirapril than placebo (5.8% vs 1.7%, respectively). Similarly, the number and severity of the changes in laboratory variables did not differ between placebo vs
spirapril, and none of these changes were dose-related. In conclusion, the studied dosages of
spirapril were equally effective in reducing DBP, and the overall good decrease in blood pressure at the end of the dosing interval indicates that once-daily administration is effective in patients with mild-to-moderate
hypertension.