Calcium antagonists and beta blockers in the control of mild to moderate systemic hypertension, with particular reference to verapamil and propranolol.
The antianginal and antiarrhythmic role of calcium antagonists is well established. Recent preliminary studies have indicated that, like beta 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 less than 0.01) and standing by 7.6% (p less than 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 less than 0.01), propranolol by 7.5% (p = 0.01); the standing diastolic blood pressure was reduced by 10.7% with verapamil (p less than 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 less than 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.