Comparison of nifedipine, prazosin and hydralazine added to treatment of hypertensive patients uncontrolled by thiazide diuretic plus beta-blocker.

In 93 patients with hypertension uncontrolled by bendrofluazide 5 mg plus atenolol 100 mg daily, the effects of adding nifedipine (up to 60 mg/day, n = 31), prazosin (up to 20 mg/day, n = 31), or hydralazine (up to 200 mg/day, n = 31) were compared in a 6 month open random parallel group study. The three drugs did not differ significantly as regards antihypertensive effect, withdrawal rate, total number of side effects, or effect on serum biochemical variables. The pattern of side-effects differed. Headache, flushing and oedema were common with nifedipine, tiredness and drowsiness with prazosin, and headache with hydralazine. Nifedipine is an acceptable third-line antihypertensive drug which may have some advantage over hydralazine and prazosin.