Nifedipine, captopril, metoprolol and nifedipine with metoprolol in hypertensive crisis in non-intensive care setting.

In 102 cases of severe hypertension (DBP > or = 115 mm Hg), with or without acute complications, efficacy and safety of SL Nifedipine 10 mg (NIF), SL Captopril 25 mg (CAP), IV Metoprolol 15 mg (MET) and SL NIF + IV MET were studied in an inpatient trial. Maximum mean percent reduction in SBP was 13.3, 9.7, 15.7 and 19.9 and in DBP was 21.2, 13.9, 12.5 and 20.4 with NIF, CAP, MET and NIF + MET respectively. A safe DBP of < or = 110 mm Hg (Kaplan) was achieved in 90, 61, 72.2 and 95.2 percent of patients. A statistically significant fall in DBP was observed at 5 minutes with all regimens except CAP which was at 15 minutes. Mild side effects observed were palpitations and flushing (NIF n = 4), taste disturbances (CAP n = 3), heaviness of head (CAP n = 1) and giddiness (MET n = 2, NIF + MET n = 2). The trial data suggest that hypertensive crisis can be managed, without intensive care facility, with all four regimens; this implies significant cost containment.

Sublingual nifedipine and captopril in hypertensive urgencies and emergencies.

Fifty two patients of severe hypertension, diastolic blood pressure > or = 115 mmHg, with or without acute complications, were treated with sublingual nifedipine 10 mg or sublingual captopril 25 mg in a randomized prospective in patient study with careful clinical monitoring. Both the drugs were safe and effective in rapidly lowering blood pressure. Nifedipine appeared to be superior to captopril with earlier onset of action, greater magnitude of response and longer duration of action. No significant side effects were observed in either of the two groups.

Effects of verapamil and nifedipine on psychomotor performance in human subjects.

The present study was undertaken to evaluate the effects of two structurally dissimilar calcium channel blockers, verapamil (a phenylalkylamine) in a single dose of 40 and 80 mg, and nifedipine (a dihydropyridine) in a single dose of 10 and 15 mg, on psychomotor performance and higher mental functions in human volunteers. Placebo and diazepam (5 mg) were used as negative and positive controls respectively. For evaluating these functions, tests employed were arithmetic ability, visual and auditory reaction time, letter (alphabet) cancellation, rapid fire arithmetic deviation and short term memory for playing cards. Careful record was kept of the heart rate, blood pressure and side effects of the therapy, each time the psychomotor tests were performed. Verapamil, both in 40 and 80 mg dose, was found to impair the performance of subjects to a significant extent in auditory reaction time, letter cancellation and short term memory. These effects were similar to those observed with administration of diazepam. With nifedipine, impairment in performance was observed only in rapid arithmetic deviation test. Thus, calcium channel antagonists, specially verapamil, impaired psychomotor performance of human subjects in our study.

Captopril--nifedipine interaction in hypertension.

Nifedipine, a calcium channel blocker exerts significant peripheral vasodilatory activity in hypertensive patients. It has been postulated that the antihypertensive effect of peripherally acting vasodilators is masked, by counter regulatory mechanism e.g. activation of renin-angiotensin aldosterone (RAA) axis. The present work was undertaken to study the effect of blockade of RAA axis using captopril, an angiotensin converting enzyme inhibitor on the blood pressure lowering activity of nifedipine. Pretreatment with captopril in a dose of 25 mg. bd was carried out for 4 weeks in one group of 10 patients before administering nifedipine 10 mg bd for 4 weeks. The other matched group of 10 patients received nifedipine alone in the same dose. It was observed that although captopril by itself had no appreciable effect on blood pressure in the dose used, it significantly enhanced the blood pressure lowering activity of nifedipine. It appears that counterregulatory mechanisms play an important role in determining the net antihypertensive effect of peripheral vasodilators.