Pharmacokinetics and acute side-effects of nifedipine given as slow-release tablets or liquid-filled capsules.
The pharmacokinetics and acute adverse effects of nifedipine were studied in a cross-over, single dose (20 mg) study on ten healthy young volunteers. From the liquid-filled capsules, nifedipine was absorbed rapidly (tmax at 30-40 min). From tablets, the peak concentration was 79-88% lower and occurred 74-133 min after ingestion; also the bioavailability was lower, as indicated by on average 39% lower area under curve values after tablets. All the volunteers experienced side-effects: the most common (nine out of the ten) and the most intense was headache. One volunteer withdrew because of unbearable vomiting and headache. Also others felt nauseous (six out of nine who continued) and four of them vomited. After tablets, the dizziness was markedly less than after capsules, but the more slowly-appearing symptoms such as headache and nausea were similar after both types of drug products. By using slow-release tablets instead of capsules it seems possible to avoid some side-effects of nifedipine, but this benefit is gained at the expense of bioavailability.
Department of Pharmacology and Toxicology, University of Kuopio, Finland.
V
V
Saano
O
O
Raatikainen
P
P
Paronen
H
H
Komulainen
D000328:Adult; D002214:Capsules; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D004341:Drug Evaluation; D005260:Female; D006801:Humans; D008297:Male; D009543:Nifedipine / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics*; D013607:Tablets
D002214:Capsules; D003692:Delayed-Action Preparations; D013607:Tablets; D009543:Nifedipine