Drug interaction between clopidogrel and proton pump inhibitors

Area of Science:

• Pharmacology
• Cardiovascular Medicine
• Drug Interactions

Background:

• Proton pump inhibitors (PPIs) are often prescribed with dual antiplatelet therapy (DAPT) like aspirin and clopidogrel to prevent gastrointestinal bleeding.
• Concurrent use of PPIs with clopidogrel has raised concerns regarding potential drug interactions and reduced clopidogrel efficacy.

Purpose of the Study:

• To investigate the mechanism, evidence, and clinical implications of the interaction between clopidogrel and PPIs.
• To review available trial data on the impact of PPIs on clopidogrel's antiplatelet effectiveness and patient outcomes.

Main Methods:

• A comprehensive literature search of MEDLINE and reference lists was conducted for English-language clinical trials (1966-September 2009).
• Included studies examined surrogate outcomes (platelet aggregation) and clinical outcomes (cardiac events, mortality).
• Four trials on surrogate outcomes and eight trials on clinical outcomes were analyzed.

Main Results:

• Two surrogate outcome studies indicated PPIs negatively impacted clopidogrel response and increased platelet aggregation.
• Three published and three unpublished clinical outcomes studies suggested an association between PPI use and increased rates of acute myocardial infarction, rehospitalization, death, or stroke.
• Conflicting results were observed in some studies, highlighting the controversial nature of the interaction.

Conclusions:

• Current evidence, primarily from observational studies, suggests some PPIs may diminish clopidogrel's antiplatelet effectiveness, potentially increasing adverse cardiac events.
• The causal relationship remains unclear due to conflicting data, necessitating careful risk-benefit assessment for patients on DAPT.
• Further randomized controlled trials are required to definitively clarify this drug interaction.