Nifedipine in the treatment of hypertension.

Nifedipine, a calcium antagonist with a predominant vasodilator action, was evaluated for the treatment of hypertension. A 20 mg-tablet, with a slower absorption and a more sustained blood-level than provided by the 10 mg-capsule was administered to 20 patients. The duration of the trial was 20 weeks. All patients achieved a significant reduction in both systolic (p less than 0.05) and diastolic (p less than 0.001) blood-pressure (B.P.), but 10 patients were withdrawn before completion of the trial period. Two patients, although achieving a fall in B.P. which was significant, did not reach to target level (less than 160/90) on maximal dosage, one patient suffered a stroke due to a cerebral infarct, and seven patients were withdrawn because of side-effects due mainly to vasodilatation. The remaining 10 patients obtained a satisfactory response. In nine patients, who had achieved a satisfactory result, there was no change in plasma renin activity (P.R.A.) during chronic nifedipine administration.