ABSTRACT
Dilevalol, an optical isomer of labetalol, combines beta-blocking and vasodilator actions which prevent reflex tachycardia and it also has intrinsic beta-2-agonist action. Its low alpha-blocking action prevents orthostatic hypotension and improves first dose tolerance. The present study evaluates the efficacy and safety of dilevalol comparing it with captopril and nifedipine. Fifty-eight mild to moderate essential hypertensive patients were studied. After a 2 to 3 week placebo lead-in phase, patients with diastolic blood pressure between 95 and 105 mmHg were included., Patients were randomly assigned to one of the 3 study drugs for a 4-week period. Initially, 15 patients received dilevalol 200 mg qd and 15 captopril 100 mg bid; afterwards, 14 received dilevalol 200 mg qd and 14 nifedipine 40 mg bid. In the first group dilevalol decreased mean blood pressure (MBP) from 118.0 +/- 1.3 to 107.3 +/- 2.7 mmHg at week 4 and captopril from 117.8 +/- 1.2 to 108.6 +/- 2.7 (p less than 0.05). When dilevalol and nifedipine were compared, the former decreased MBP from 116.0 +/- 2.0 to 104.3 +/- 3.2 mmHg and the latter from 115.0 +/- 1.4 to 106.0 +/- 3.0 (p less than 0.05). The drug was well tolerated without evidence of orthostatic hypotension. Our results demonstrate that dilevalol is as safe and effective as captopril and nifedipine for the treatment of essential hypertension.
