Enhanced antiplatelet effect of enteric- -coated acetylsalicylic acid in co-administration with pantoprazole

Abstract

Background. Proton pump inhibitors (PPI) are recommended for patients receiving antiplatelet therapy.Several studies have revealed that PPI may attenuate the antiplatelet effect of ASA. However, our pilot study has indicated a positive interaction between pantoprazole and enteric-coated aspirin.The aim of the current study was to confirm that pantoprazole enhances the antiplatelet effect ofenteric-coated aspirin in patients with acute coronary syndrome (ACS) treated with dual antiplatelettherapy. Moreover, the influence of CYP2C19 polymorphism on the antiplatelet effect of aspirinwas assessed.

Material and methods. Ninety three consecutive ACS patients were prospectively enrolled in a randomized, crossover, open-labeled study. Forty four patients were given orally 40 mg of pantoprazole for the initial fourdays while the remaining forty nine were treated with pantoprazole from the 5th to the 8th day of hospitalization. Blood samples were collected at 6.00 a.m., 10.00 a.m., 2.00 p.m., and 7.00 p.m. on the 4th and 8th daysof hospitalization. Aggregation in response to arachidonic acid was assessed by impedance aggregometry.

Results. Lower mean platelet aggregation on pantoprazole was observed on the 8th day of hospitalization(p = 0.03). A cross-time analysis of platelet aggregation demonstrated statistical significance at two hoursand six hours after co-administration of pantoprazole and antiplatelet agents, with the highest absolutedifference observed two hours after drugs ingestion. No significant differences in aggregation betweenstudy groups were observed on the 4th day of hospitalization. No influence of CYP2C19 polymorphismon the antiplatelet effect of aspirin was observed.

Conclusions. Co-administration of pantoprazole enhances the antiplatelet effect of enteric-coated aspirinin patients with ACS.