Impact of the FDA Warning for Azithromycin and Risk for QT Prolongation on Utilization at an Academic Medical Center.

A US Food and Drug Administration (FDA) drug safety communication was released in March 2013, warning prescribers of the risk of QT prolongation associated with azithromycin. Overall azithromycin utilization and adherence to an inpatient QTc monitoring guideline during 8-month time periods before and after the warning were assessed to evaluate the impact of this warning on inpatient azithromycin utilization and QTc monitoring. Fifty-five patients were included in the prewarning time period and 50 were included in the postwarning period. A significant reduction in utilization in days of therapy per 1,000 patient days was observed (31.2 prewarning vs 17.5 postwarning, p < .001) in these groups. No changes in QTc monitoring among patients receiving azithromycin were identified. FDA warnings of severe, life-threatening toxicities can have a profound impact on utilization and prescribing of medications, however they may not necessarily change monitoring practices.