Previous advice recommended against using clopidogrel in combination with PPIs due to concerns that the efficacy of clopidogrel may be reduced. This update notes that since this advice was issued several further studies have raised doubts as to whether the interaction is clinically significant.
It is also noted that two studies have confirmed that circulating levels of clopidogrel in the blood are reduced by omeprazole. This supports the hypothesis of an interaction between clopidogrel and omeprazole and esomeprazole. The review suggests that, "there are no solid grounds to extend the warning to other PPIs".
Action: Clinicians should be aware of this interaction. Concomitant use of clopidogrel with omeprazole or esomeprazole should be avoided where possible.