title: Rectal administration of nifedipine: haemodynamic effects and pharmacokinetics in hypertensives.
abstract: The haemodynamic effects and pharmacokinetics of nifedipine suppositories, used mainly for hypertensive emergencies, were studied in 10 severely hypertensive patients. Following rectal administration, significant hypotensive effects occurred after 0.5 h and lasted until 7 h after administration. The mean (+/- SE) maximum decreases in systolic and diastolic blood pressures 1.5 h after administration were: systolic, 61.8 +/- 7.9 mmHg (P less than 0.001); and diastolic, 30.8 +/- 4.0 mmHg (P less than 0.001). No serious side-effects were reported and heart rate did not change significantly. Mean nifedipine concentration in the blood peaked at 52.4 ng/ml, 1 h after administration and, after 7 h, was still 14.3 ng/ml which is higher than the minimum plasma concentration required for hypotensive effects to occur. There was a close correlation between nifedipine concentration in the blood and hypotensive effects. These results indicate that rectal administration of nifedipine should be regarded as a useful alternative treatment in hypertensive emergencies.
mesh_terms: D000285:Administration, Rectal; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001682:Biological Availability; D001794:Blood Pressure / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000008:administration & dosage* / Q000097:blood / Q000627:therapeutic use
chemical_list: D009543:Nifedipine