Concomitant use of clopidogrel and proton pump inhibitors: A retrospective analysis of prescription behaviour

AIMS: Since omeprazole and esomeprazole reduce the effect of clopidogrel on the inhibition of platelet aggregation, concomitant use of these drugs has been discouraged by the Food and Drug Administration (FDA) and European Medicines Agency (EMA) since 2010. Currently, it is unknown how often this undesired drug-drug combination is prescribed. The aim of this article is to determine the proportion of patients using omeprazole or esomeprazole among patients using clopidogrel with gastroprotective drugs and to identify differences between these two groups with regard to patient characteristics and prescriber characteristics. METHODS: This was a retrospective analysis of Dutch outpatient medication prescription records between 2015 and 2022. The database had a coverage of approximately 62% of all outpatient prescriptions dispensed in The Netherlands. RESULTS: The proportion of patients using omeprazole or esomeprazole as gastroprotective drug in combination with clopidogrel declined from 19.7% to 8.7% between 2015 and 2022. The undesired drug-drug combination was more often prescribed by internists, to women and to patients with polypharmacy (using >10 drugs). CONCLUSIONS: Although the proportion of patients using clopidogrel together with omeprazole or esomeprazole declined between 2015 and 2022, the undesired combination is still frequently prescribed in The Netherlands. Education about this drug-drug interaction for pharmacists and prescribers is needed since pharmacotherapeutic alternatives are available.