Changes in emergency department visits for zolpidem-attributed adverse drug reactions after FDA Drug Safety Communications.

Purpose: To identify possible changes in U.S. emergency department (ED) visits from zolpidem-attributed adverse drug reactions (ADRs) after 2013 Food and Drug Administration (FDA) Drug Safety Communications (DSCs), which notified the public about FDA's new dosing recommendations for zolpidem.
Methods: We estimated the occurrence of ED visits from zolpidem-attributed ADRs using nationally representative, public health surveillance of medication harms (National Electronic Injury Surveillance System-Cooperative Adverse Drug Event Surveillance project, 2010-2017). We estimated the number of zolpidem prescriptions using IQVIA National Prescription Audit, 2010-2017. We calculated rates of ED visits for zolpidem-attributed ADRs per 10 000 dispensed zolpidem prescriptions and identified time trends and potential inflection points using joinpoint regression. For comparison, we repeated these analyses for sedating antidepressants commonly used to treat disordered sleep (trazodone, doxepin, and mirtazapine).
Results: The best-fit regression model for rates of ED visits for zolpidem-attributed ADRs by 6-month intervals identified a single inflection point in the second half of 2014 (P = .024) with a 6.7% biannual decrease from 2010 to 2014 ([-13.1%, 0.3%], P = .059) and a 13.9% biannual increase from the second half of 2014 through 2017 ([-1.1%, 31.3%], P = .068). No change or inflection points were identified for rates of ED visits for sedating antidepressant-attributed ADRs. Conclusions: While there was a nominal decline in the rate of ED visits for ADRs in the time period before and for 18 months after FDA's 2013 zolpidem DSCs, the decrease was not sustained, and thus questions remain concerning the long-term impact of the zolpidem DSCs on ADRs.