Adverse events reported to FDA adverse event reporting system for long-acting injectable buprenorphine during the first 18 months postlaunch

Introduction Once-monthly (Sublocade®, BUP-SB) and weekly and monthly (Brixadi®, BUP-BX) long-acting injectable buprenorphine formulations are approved for moderate-to-severe opioid use disorder. US Food and Drug Administration Adverse Event Reporting System (FAERS) data received for these medications were analyzed and summarized. Methods Adverse events (AEs) reported to FAERS during the first 18 months postlaunch for BUP-SB (March 1, 2018–August 31, 2019) and BUP-BX (September 5, 2023–February 28, 2025) were examined. We determined reporting rates (RRs) were determined using the number of AEs containing a specific Medical Dictionary for Regulatory Activities–preferred term per 1000 patients treated (RR pt ) and 1000 units sold (RR rx ). Results In total, 3848 and 2080 AE terms were reported to FAERS for BUP-SB and BUP-BX, respectively. The RR pt for BUP-SB and BUP-BX for the 15 AEs most frequently reported to FAERS was withdrawal syndrome (40.6, 5.7), injection site pain (33.6, 1.6), drug dependence (10.6, 1.1), injection site erythema (9.8, 1.0), injection site discharge (7.4, <0.1), nausea (7.2, 1.3), drug abuse (6.5, 0.2), therapeutic product effect incomplete (5.7, 0.2), inappropriate schedule of product administration (5.0, 0.1), wrong technique in product usage process (4.7, 0.1), fatigue (4.5, 0.8), headache (4.0, 0.5), hyperhidrosis (3.9, 0.8), injection site pruritus (3.9, 0.6), and maternal exposure during pregnancy (3.8, 0.3). Corresponding RR rx values ranged from 1.1 to 11.7 for BUP-SB and < 0.1 to 1.2 for BUP-BX. Conclusions FAERS AE reporting rates for BUP-SB and BUP-BX were low. The most commonly reported AEs were similar to those observed in clinical trials. These data provide insight into AE reporting patterns for long-acting injectable buprenorphine medications following their marketing authorization.