Cumulative number of U.S. Food and Drug Administration generic approvals (right axis, line graph) and the nationally estimated annual number of prescriptions dispensed (left axis, bar graph) from U.S. outpatient retail pharmacies for opioid analgesics with “newly marketed generics,” stratified by brand (brand and branded generic) and generic products from 2006 through 2015. Source: IQVIA, National Prescription Audit. *Branded: All trade name products including Brand and Branded Generic products. **Newly marketed generics: Generic versions for opioid analgesics, where the generics were dispensed for the first time during 2006–2015. Excludes injectable formulations, opioid-containing cough/cold products, and opioid-containing medication assistance therapy products. Oral solid products for Transmucosal Immediate-Release Fentanyl (TIRFs) were included. Brand TIRF products include Abstral, Actiq, Fentora, Onsolis (does not include sprays). Brand product of hydromorphone ER includes Exalgo. Brand products of tramadol include Ultram ER, Conzip, and Ryzolt. ER = extended-release formulation; IR = immediate-release formulation.