The changing landscape of naloxone availability in the United States, 2011 - 2017.

Opioid overdose deaths have been on the rise in the United States since 1999. Naloxone is a competitive opioid antagonist that rapidly reverses opioid overdose. The implementation of naloxone access laws and development of naloxone formulations that can be administered by laypersons have coincided with changes in the landscape of naloxone availability in the United States. Using data from IQVIA's National Prescription Audit we present the number of naloxone prescriptions dispensed quarterly from 2011 through the second quarter of 2017. The data demonstrate that nationwide naloxone dispensing increased nearly eight-fold from the fourth quarter of 2015 to the second quarter of 2017. Narcan was the most commonly prescribed naloxone formulation as of the second quarter of 2017, accounting for 68% of prescriptions during that quarter followed by Evzio (20%). There was considerable variability in the extent to which states experienced increases in naloxone dispensing, which may represent a general state-specific response to the opioid crisis, rather than direct association with opioid overdose death rates in a particular state. Although naloxone access laws continue to increase the amount of naloxone dispensed, cost remains a concern in terms of wide distribution of the life-saving medication.