Methylergonovine maleate and the risk of myocardial ischemia and infarction.

OBJECTIVE

The purpose of this study was to examine the risks of acute coronary syndrome (ACS) and acute myocardial infarction (AMI) that are associated with methylergonovine maleate (Methergine; Novartis Pharmaceuticals Corporation, Plantation, FL) use in a large database of inpatient delivery admissions in the United States.

STUDY DESIGN

We conducted a retrospective cohort study using data from the Premier Perspective Database and identified 2,233,630 women who were hospitalized for delivery between 2007 and 2011 (approximately one-seventh of all US deliveries during this period). Exposure was defined by a charge code for methylergonovine during the delivery hospitalization. Study outcomes included ACS and AMI. Propensity score matching was used to address potential confounding.

RESULTS

Methylergonovine was administered to 139,617 patients (6.3%). Overall, 6 patients (0.004%) who were exposed to methylergonovine and 52 patients (0.002%) who were not exposed to methylergonovine had an ACS. Four patients (0.003%) who were exposed to methylergonovine and 44 patients (0.002%) in the not-exposed group had an AMI. After propensity score matching, the relative risk for ACS that was associated with methylergonovine exposure was 1.67 (95% confidence interval [CI], 0.40-6.97), and the risk difference was 1.44 per 100,000 patients (95% CI, -2.56 to 5.45); the relative risk for AMI that was associated with methylergonovine exposure was 1.00 (95% CI, 0.20-4.95), and the risk difference was 0.00 per 100,000 patients (95% CI, -3.47 to 3.47).

CONCLUSION

Despite studying a very large proportion of US deliveries, we did not find a significant increase in the risk of ACS or AMI in women who received methylergonovine compared with those who did not; estimates were increased only modestly or not at all. The upper limit of the 95% CI of our analysis suggests that treatment with methylergonovine would result in no more than 5 additional cases of ACS and 3 additional cases of AMI per 100,000 exposed patients.