Methylergonovine maleate and the risk of myocardial ischemia and infarction

Abstract

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.

Keywords: methylergonovine; myocardial infarction; postpartum hemorrhage; uterine atony.