Acute antihypertensive effect of nifedipine by sublingual route in cases with clinically severe systolic hypertension. A study up to 4 h after administration

In a multi-center study, nifedipine (Bay a 1040, Adalat(®)) (10 mg capsule) was administered, in liquid form and sublingually, to 22 cases who were diagnosed as having clinically severe systolic hypertension, and the depressor effect of the treatment was studied over a period of 4 h. In emergency patients (cerebral hemorrhage n = 8, cerebral thrombosis n = 4, subarachnoid hemorrhage n = 1, renal failure n = 6, essential hypertension n = 3), 3 bouts of blood pressure measurement at intervals of 10-15 min during the control period were carried out. In case of systolic blood pressure higher than 200 mmHg, at least once, nifedipine at a dose of 10 mg was sublingually administered. Thereafter, blood pressure and pulse rate were recorded at intervals of 15 min up to the end of the first hour, then at intervals of 30 min up to the end of 4 h. Results were as follows. 1. In terms of the average values for all cases, blood pressure fell to near lowest levels by the end of about 30 min after the administration and it stayed at near lowest levels up to the end of 120-240 min. During this period of time, pulse rate remained substantially unchanged. 2. In terms of the pattern of the blood pressure fall, all cases could be classified generally into two types, namely (a) the 'dip' group (7 cases) in which blood pressure fell to the lowest level to form a 'dip' and remained below the control level, although it showed a trend to return to the control level for 4 h and (b) the 'flat' group (15 cases) in which blood pressure declined gradually for about 1 h and then remained low or below the control level, although it showed a trend to return to the control level throughout the rest of the observation period of 4 h. The mechanism of these different patterns of blood pressure response was discussed. 3. What appeared to be side effects were observed in 3 cases but these disappeared in short periods of time. Thus, the results suggest that the sublingual administration of nifedipine is very useful as antihypertensive therapy in clinically severe systolic hypertension.