NEW YORK (Reuters Health) – Another study has shown an interaction between clopidogrel and proton pump inhibitors. The findings indicate that patients who receive clopidogrel and a PPI after discharge for an acute coronary syndrome (ACS) are at greater risk for adverse outcomes than those treated with only clopidogrel.

Specifically, use of clopidogrel and a PPI increased the odds of death or rehospitalization for ACS by 25%, according to the report in the Journal of the American Medical Association for March 4.

Previous studies have found that some PPIs reduce the anti-platelet effects of clopidogrel. Whether this effect was clinically relevant, however, was unclear.

In the current study, Dr. P. Michael Ho, from Denver VA Medical Center, and colleagues analyzed data from 8205 ACS patients who were prescribed clopidogrel at discharge from Veterans Affairs hospitals in the US from October 2003 to January 2006. Overall, 63.9% of patients were also prescribed a PPI at discharge, during follow-up, or both.

The percentage of patients who died or were rehospitalized for ACS was higher in the PPI group than in those not taking a PPI: 29.8% vs. 20.8%. Further analysis showed that PPI-treated patients were at increased risk for hospitalization for recurrent ACS and for revascularization procedures, but not for overall mortality.

In 6450 other subjects who did not receive clopidogrel at hospital discharge, PPI use alone did not raise the risk of death or rehospitalization for ACS, the report shows.

“Pending further studies to confirm these results and prospectively assess cardiovascular outcomes for patients taking clopidogrel plus PPI vs. clopidogrel without PPI, the results of this study may suggest that PPIs should be used for patients with a clear indication for the medication, rather than routine prophylactic prescription,” the authors conclude.

Reference:
JAMA 2009;301:937-944.