Antihypertensive effect and profile of action of quinapril in mild and moderate hypertension

In the present study, which was conducted as an open randomized multicenter study with 2 parallel groups by 11 private doctors, the effects of both quinapril and enalapril in a dose of 10 mg given once in the morning were compared over a period of 6 weeks. Eighty-two patients with mild to moderate hypertension were included into the study (40 for quinapril, 42 for enalapril). Demographic and clinical data, including the duration and severity of hypertension, were not significantly different between both groups. Office blood pressure was lowered in the quinapril group from 160.5 ± 15.0/97.1 ± 5.3 mmHg to 140.9 ± 10.3/86.4 ± 7.2 mmHg within 6 weeks (difference -19.6 ± 15.0/-10.6 ± 8.9 mmHg, each mean ± standard deviation). In the enalapril group, office blood pressure was lowered from 161.7 ± 10.3/99.9 ± 5.5 mmHg to 140.2 ± 11.7/87.5 ± 7.9 mmHg (difference -21.5 ± 13.5/-12.4 ± 8.7 mmHg). There were no significant changes in heart rate during treatment. For quinapril the 24-hour blood pressure recording revealed a lowering of diastolic blood pressure from 95.8 ± 7.7 to 88.3 ± 8.9 mmHg (difference -7.5 ± 9.5 mmHg). Enalapril lowered diastolic blood pressure to a comparable extent from 94.6 ± 6.9 mmHg to 87.4 ± 8.3 mmHg (difference -7.2 ± 8.6 mmHg). The mean daytime systolic blood pressure was also influenced similarly by both antihypertensives, from 145.9 ± 9.9 to 136.5 ± 10.7 mmHg (difference -9.4 ± 13.0 mmHg) by quinapril and from 145.8 ± 11.2 to 136.3 ± 12.6 mmHg (difference -9.6 ± 13.5 mmHg) by enalapril. Likewise, the 24-hour blood pressure profile was affected similarly by both substances, revealing no indications of a different duration of action. The results show a comparable effect of 10 mg enalapril and 10 mg quinapril on both 24-hour blood pressure over the whole 24-hour period and office blood pressure of patients with mild to moderate hypertension. Therefore, both drugs exhibit similar actions in a dosage of 10 mg daily in mild to moderate hypertension.