Coadministration of clopidogrel and proton pump inhibitors

To the Editor: Thank you for the excellent review on proton pump inhibitors (PPIs) in the January 2011 issue.¹ I would like to make the following comments about Dr. Madanick’s suggested algorithm (see Figure 2 in the article) for deciding whether to use a PPI in patients requiring clopidogrel:

A posting dated October 27, 2010, on the Web site of the US Food and Drug Administration (FDA) states the following: “With regard to the proton pump inhibitor (PPI) drug class, this recommendation [against the concomitant use of Plavix (clopidogrel) and omeprazole (Prilosec)] applies only to omeprazole and not to all PPIs. Not all PPIs have the same inhibitory effect on the enzyme [CYP2C19] that is crucial for conversion of Plavix into its active form. Pantoprazole (Protonix) may be an alternative PPI for consideration. It is a weak inhibitor of CYP2C19 and has less effect on the pharmacological activity of Plavix than omeprazole.”² Thus, when it is deemed necessary to coadminister clopidogrel with a PPI, pantoprazole appears to be the preferred PPI.

If the patient is taking clopidogrel for stroke prophylaxis, one can consider switching to Aggrenox (aspirin plus extended-release dipyridamole), which has no warnings regarding coadministration with PPIs.

Patients taking aspirin plus clopidogrel may benefit by the addition of misoprostol (Cytotec), which is indicated for reducing the risk of aspirin-induced gastric ulcers in patients at high risk of complications from gastric ulcer.