The impact of treatment with omeprazole on the effectiveness of clopidogrel drug therapy during the first year after successful coronary stenting.

BACKGROUND

Because clopidogrel is converted to its active metabolite by P450 isoenzymes, which are also involved in the metabolism of omeprazole, there is concern regarding whether the action of clopidogrel would be reduced in patients also taking omeprazole.

OBJECTIVE

To evaluate the impact of omeprazole administration on the effectiveness of clopidogrel drug therapy during the first year following successful coronary stenting (CS).

METHODS

A total of 588 consecutive patients who underwent successful CS for stable or unstable coronary artery disease were studied. Patients were classified into those who were treated (group A, n=340) or not treated (group B, n=248) with omeprazole for seven or more consecutive days during the entire observation period. The composite of cardiac death or rehospitalization for nonfatal myocardial infarction during the first year was the prespecified primary study end point.

RESULTS

Baseline characteristics, and dual clopidogrel and acetylsalicylic acid drug therapy were well balanced between the study groups. By one year, the primary end point was reached by 58 (9.9%) patients, including 20 (3.4%) who died due to cardiac reasons and 38 (6.5%) who were rehospitalized because of a nonfatal myocardial infarction. Patients in groups A and B, respectively, were at similar risk of the primary composite end point (10% versus 9.7%, hazard ratio 1.1 [95% CI 0.6 to 1.8]; P=0.89).

CONCLUSIONS

According to the results of the present study, treatment with omeprazole had no impact on the clinical efficacy of clopidogrel drug therapy during the first year after successful CS.