title: Influence of single- and multiple-dose omeprazole treatment on nifedipine pharmacokinetics and effects in healthy subjects.
abstract: The effects of single dose (20 mg) and short-term (20 mg/day for 8 days) oral treatment with omeprazole on the pharmacokinetics and effects of oral nifedipine (10 mg capsule) and on gastric pH have been investigated in a randomized, double-blind, placebo-controlled cross-over study in 10 non-smoking healthy male subjects. The single dose of omeprazole had no significant effect on any pharmacokinetic parameter of nifedipine, nor on gastric pH, or blood pressure or heart rate. Short-term omeprazole treatment increased the AUC of nifedipine by 26% (95% confidence interval 9-46%), but all other pharmacokinetic parameters of nifedipine, including elimination half-life, Cmax, tmax, and recovery of the main urinary metabolite, were not significantly changed. The median gastric pH during the absorption phase of nifedipine was increased by short-term omeprazole (pH 4.2) compared to placebo treatment (pH 1.4). Blood pressure and heart rate did not differ between treatments. The interaction between nifedipine and omeprazole is not likely to be of major clinical relevance.
authors.affiliation: Division of Pharmacology, University of Leiden, The Netherlands.
authors.forename: P A
authors.initials: PA
authors.lastname: Soons
authors.forename: G
authors.initials: G
authors.lastname: van den Berg
authors.forename: M
authors.initials: M
authors.lastname: Danhof
authors.forename: P
authors.initials: P
authors.lastname: van Brummelen
authors.forename: J B
authors.initials: JB
authors.lastname: Jansen
authors.forename: C B
authors.initials: CB
authors.lastname: Lamers
authors.forename: D D
authors.initials: DD
authors.lastname: Breimer
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001794:Blood Pressure / Q000187:drug effects; D004311:Double-Blind Method; D004347:Drug Interactions; D005745:Gastric Acidity Determination; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D009543:Nifedipine / Q000009:adverse effects / Q000493:pharmacokinetics* / Q000494:pharmacology; D009853:Omeprazole / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D012016:Reference Values
chemical_list: D009543:Nifedipine; D009853:Omeprazole