Calcium antagonists and beta blockers in the control of mild to moderate systemic hypertension, with particular reference to verapamil and propranolol

Abstract

The antianginal and antiarrhythmic role of calcium antagonists is well established. Recent preliminary studies have indicated that, like β blockers, calcium antagonists may produce short- and long-term hypotensive effects in patients with mild to moderate essential hypertension. The pharmacologic properties of calcium antagonists provide a clear rationale for their use in the control of essential hypertension. The comparative hypotensive effects of verapamil (80 to 160 mg 3 times a day) and propranolol (40 to 120 mg 3 times a day) were evaluated over 4 weeks, preceded by a 4-week placebo phase, in a double-blind protocol in 17 patients with mild to moderate hypertension. Verapamil (n = 10) reduced the mean sitting systolic blood pressure by 10.7% (p < 0.01) and standing by 7.6% (p < 0.04). The corresponding data for propranolol (n = 7) were 4.8% (not significant) and 5% (p = 0.04). Verapamil reduced the sitting diastolic blood pressure by 10.8% (p < 0.01), propranolol by 7.5% (p = 0.01); the standing diastolic blood pressure was reduced by 10.7% with verapamil (p < 0.01) and by 8.6% (p = 0.01) with propranolol. With verapamil the mean heart rate fell from 77.60 ± 8.42 to 70.20 ± 4.85 beats/min (p = 0.03); with propranolol it fell from 76.85 ± 6.91 to 66.29 ± 4.54 beats/min (p < 0.01). Although a trend towards a slightly greater hypotensive effect was apparent with verapamil compared with propranolol, the difference was not statistically significant. It is concluded that verapamil and propranolol exert comparable hypotensive potency in patients with mild to moderate hypertension.