Verapamil compared with nifedipine in the treatment of essential hypertension.

In a double-blind, cross-over study for 6 weeks that included 28 patients with essential hypertension, WHO stage I-II, the hypotensive action of verapamil (160 mg thrice daily) was compared with nifedipine (20 mg slow release twice daily). Twenty-six patients completed the trial. Both regimens reduced the blood pressure significantly in patients in the supine, sitting, and standing positions, with sustained and slightly increasing effect throughout the periods. Verapamil reduced mean diastolic blood pressure significantly more than nifedipine in all positions and lowered mean systolic pressure slightly more than nifedipine. Resting heart rate was significantly decreased by verapamil and insignificantly altered by nifedipine. Serum lipoproteins, liver function tests, serum creatinine, serum electrolytes (Na+, K+, and Cl-), and body weight were not affected by either drug. Atrioventricular (AV) conduction was significantly prolonged by verapamil and unaffected by nifedipine. Subjective side effects were more numerous with nifedipine than with verapamil, but were mainly mild and transient except for one patient in each group who was withdrawn because of severe adverse reactions. It is concluded that the calcium antagonists verapamil and nifedipine have a significant hypotensive effect, more pronounced with verapamil than with nifedipine in the actual doses. Both drugs are treatment alternatives in mild to moderate essential hypertension.