Transmucosal immediate-release fentanyl (TIRF) drugs are potent, rapid-acting opioids approved to treat breakthrough pain in patients with cancer who are tolerant to other around-the-clock opioid analgesics. In March 2012, a US Food and Drug Administration–approved Risk Evaluation and Mitigation Strategy (REMS) was implemented, mandating prescribers, distributors, pharmacies, and patients to enroll in the REMS to prescribe, dispense, or receive TIRF drugs.