Antihypertensive effect of fractionated sublingual administration of nifedipine in moderate essential hypertension.

The magnitude and duration of the antihypertensive effect of nifedipine were studied in 7 cases of moderate essential hypertension. In a double-blind crossover study, nifedipine 10 mg or a placebo were administered sublingually 4 times a day for 2 days, and the results were compared. Each dose of nifedipine reduced systolic and diastolic blood pressure by 14% both in the supine and upright positions. The antihypertensive action lasted for about 3 h and it was not cumulative. The reduction in blood pressure was associated with a temporary increase in heart rate. Administration of nifedipine 10 mg did not significantly raise plasma renin activity or plasma aldosterone. The drug was well tolerated and no side effects were detected.