Comparative study of the antihypertensive effect of verapamil and atenolol.

A clinical trial in 24 patients with essential arterial hypertension (14 women and 10 men, mean age 47.5) was conducted on a double-blind basis using a placebo, 240-mg verapamil and 100-mg atenolol daily. The total duration of the trial was 12 weeks: a 2-week washout period on placebo, a 4-week period on one of the trial drugs, a second 2-week weaning period and a further 4-week treatment period on the other trial drug. Stabilization of the hypertension was obtained in 80% of the patients on verapamil and 71% of the patients on atenolol both in the supine and upright positions; there was no significant difference between the 2 drugs. A moderate decrease in heart rate was obtained. Sinus bradycardia was observed in 3 patients on verapamil and 4 patients on atenolol. No instances of atrioventricular block were observed on electrocardiogram. No adverse effects were reported with verapamil and in only 1 patient taking atenolol. Adequate stabilization of hypertension appears possible in most patients with both verapamil and atenolol.