No effect of short-term omeprazole intake on acenocoumarol pharmacokinetics and pharmacodynamics
Authors: de Hoon, J. N. J. M.1; Thijssen, H. H. W.1; Beysens, A. J. M. M.2; Van Bortel, L. M. A. B.1
Source: British Journal of Clinical Pharmacology, Volume 44, Number 4, October 1997 , pp. 399-401(3)
Publisher: Blackwell Publishing
Abstract:
Aims To investigate the effect of omeprazole on the pharmacokinetics of R- and S-acenocoumarol and on their combined anticoagulant activity. Methods Eight healthy male subjects completed a double-blind, randomized, placebo-controlled, two-way cross-over study. Subjects were given either omeprazole 40 mg or placebo once daily for 3 days. On day 2 of each study period, a single 10 mg oral dose of racemic acenocoumarol was administered and venous blood samples were collected for pharmacokinetic and pharmacodynamic assessments. A wash-out period of 2 weeks separated the two study periods. Results The pharmacokinetics of R- and S-acenocoumarol (AUC 3016±221 and 233±14 ng ml−1 h, respectively) did not change after omeprazole (AUC 2929±256 and 220±18 ng ml−1 h, respectively). Anticoagulant activity (INRmax 1.7±0.1) was unaffected by co-administration of omeprazole (INRmax 1.7±0.1). Conclusions The short-term intake of omeprazole does not affect acenocoumarol pharmacokinetics or pharmacodynamics. These data differ from the results of previous studies on the effect of omeprazole on warfarin, suggesting a different in vivo interaction profile of omeprazole on acenocoumarol than on warfarin. Drug interaction studies with oral anticoagulants should not be restricted to the use of warfarin.Keywords: drug interaction; acenocoumarol; omeprazole; oral anticoagulants
Document Type: Research article
DOI: 10.1046/j.1365-2125.1997.00600.x
Affiliations: 1: Department of Pharmacology, Maastricht University, Cardiovascular Research Institute Maastricht, 2: Clinical Pharmacy, Academic Hospital Maastricht, The Netherlands

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