Abstract 10363: The Frequency of the Prescription of P-Glycoprotein-Affecting Drugs in Atrial Fibrillation.
Introduction: Vitamin-K-antagonists (VKA) are underused in atrial fibrillation (AF) because of concerns about bleeding risk, drug- and food interactions. Dabigatran is a new oral thrombin-inhibitor which had in the Re-Ly study a similar effect as VKA for stroke prevention but a lower complication rate. Dabigatran is claimed to have a low rate of drug- and food interactions. However, dabigatran-absorption is dependent on the P-glycoprotein (P-gp)-system in the gut which is influenced by drugs and food components. Aim of the cross-sectional study was to assess the prescription frequency of P-gp-affecting drugs in AF patients.
Methods: P-gp-affecting drugs were searched from the literature. Consecutive patients with AF hospitalized between December 2009 and January 2010 were included. The CHADS2 score was obtained, the medication was registered and screened for P-gp-affecting drugs.
Results: In 100 patients (47 females, mean age 74±12y) the mean CHADS2 score was 2.4±1.4. Forty-two patients took at least one, and 5/42 two P-gp-affecting drugs: Simvastatin (n=22), amiodarone (n=8), vitamin E (n=8), carvedilol (n=4), diltiazem (n=2), dipyridamole (n=1), propranolol (n=1), verapamil (n=1). VKA received 54 patients: 2/8 with CHADS2 0, 8/20 with CHADS2 1, 15/27 with CHADS2 2, 15/24 with CHADS2 3 , 10/14 with CHADS2 4, 2/5 with CHADS2 5 and 2/2 with CHADS2 6. Twenty-six of the 54 VKA-receiving patients took one (n=23) or two (n=3) P-gp-affecting drugs.
Conclusion: P-gp-affecting drugs are prescribed to 42% of hospitalized AF patients and to 48% of VKA-receiving AF patients. More information on the relevance of drug- and food interactions is warranted before dabigatran is widely used for stroke prevention. Since the present study does not offer any evidence we suggest to re-analyse bleeding and embolic events in dabigatran-investigating trials considering co-medication with P-gp-affecting drugs.
- © 2010 by American Heart Association, Inc.