Quinapril versus atenolol in the treatment of mild to moderate essential hypertension.

A randomized, double-blind, parallel-group study was conducted to compare the safety and efficacy of the angiotensin-converting enzyme inhibitor quinapril with that of the beta-blocker atenolol. Fifty-six outpatients with mild to moderate hypertension were enrolled in the trial. After a 4-week washout period, 27 patients were treated with quinapril 20 mg once daily and 29 patients were treated with atenolol 50 mg once daily for 4 weeks. During a third 4-week period, the daily doses were adjusted on an individual basis. At the end of the 8-week treatment period, the systolic and diastolic blood pressures were significantly reduced in both groups of patients. Heart rate was significantly reduced only in the atenolol group. Adverse effects were inconsequential and comparable in both groups. Quinapril was shown to be a safe and effective treatment for patients with mild to moderate hypertension.