Background: Fentanyl buccal tablet (FBT), a potent opioid, was approved in Canada in 2013 for breakthrough pain in opioid-tolerant adult cancer patients. Additional risk minimization measures (aRMMs), consisting of communications to patients and healthcare providers (HCPs), were implemented from November 2014 through September 2015.Objectives: The aim of this study was to assess the effectiveness of FBT aRMMs as measured by prescriber knowledge, understanding, and behavior regarding key safety concerns (off-label use, use in non-opioid-tolerant patients, misuse/abuse/diversion, and drug-drug interaction) and to evaluate illicit FBT use.Methods: The study included three components: (1) a knowledge and understanding (KAU) survey of FBT prescribers conducted in two waves: November 2016-February 2017 and April-September 2018; (2) a retrospective prescription study of medical records of patients treated with FBT by a subgroup of prescribers from the KAU survey; and (3) Web surveillance of illicit FBT use in Canada using the search term FENTORA (May 2014-September 2018). The aRMMs were considered effective if the lower bound of the 95% confidence interval indicated that at least 65% of respondents met or partly met the knowledge objective for each key safety concern.Results: KAU survey: Of 46 eligible HCPs, 97.8% met or partly met the knowledge objective on use in breakthrough pain cancer patients, 97.8% on use in opioid-tolerant patients, 89.1% on dose and titration, 100% on abuse/addiction, and 58.7% on drug-drug interaction. Retrospective prescription study: Of 22 FBT-treated patients identified from 14 HCPs, 45.5% had cancer, 50.0% recorded a breakthrough pain indication, and 36.4% reported opioid tolerance; however, only 13.6% of patients were prescribed FBT according to the approved indication. Web surveillance: Of 932 FBT posts in Canada, only 40 (4.3%) mentioned illicit use.Conclusions: The aRMMs as measured by the prescriber KAU were effective for most key safety messages; however, not all key messages of the aRMMs were stringently followed in routine practice. [ABSTRACT FROM AUTHOR]