Verapamil and bendrofluazide in the treatment of hypertension: a controlled study of effectiveness alone and in combination

Abstract

The effects of verapamil and bendrofluazide used singly and in combination were examined in patients with primary hypertension in a patient blind, partly observer blind placebo controlled study of parallel group design; there were ten subjects in each arm of the trial. Verapamil 160 mg twice daily caused supine mean arterial pressure to fall by 21 mmHg; this reduction was significantly greater (p less than 0.05) than that induced by bendrofluazide 5 mg daily which caused a fall of only 10 mmHg. The addition of verapamil 160 mg twice daily to bendrofluazide 5 mg daily caused a further fall in pressure of 18 mmHg (p less than 0.005), but the reduction in pressure when bendrofluazide was added to verapamil was only 1 mmHg and not significant. Bendrofluazide therapy caused a fall in plasma potassium concentration and an increase in plasma urate concentration; urinary calcium excretion was reduced. Verapamil caused no detectable biochemical alterations in plasma or urine.