Low-dose Initiation of Buprenorphine in Hospitalized Patients on Full Agonist Opioid Therapy: A Retrospective Observational Study.

OBJECTIVE: Buprenorphine can be challenging to initiate in hospitalized patients with opioid dependence because of difficulty tolerating an opioid-free period for buprenorphine induction. The objective of this study was to evaluate efficacy and safety of low-dose initiation of buprenorphine in hospitalized patients receiving full agonist opioids. METHODS: This is a retrospective observational study between January 1, 2019, and December 31, 2020, at an academic tertiary care center and affiliated community hospital. Participants included adult patients at least 18 years old receiving scheduled full agonist opioids who were given sublingual buprenorphine 0.5 mg or less with the intent of increasing to at least 4 mg daily. The primary endpoint was the proportion of patients reaching a target dose of at least 4 mg total per day. The secondary endpoints included the incidence of precipitated opioid withdrawal based on documentation of symptoms and change in morphine milligram equivalents before and after low-dose buprenorphine initiation. RESULTS: A total of 76 low-dose initiation attempts were performed in 71 predominantly male (68%) patients (some patients had multiple attempts). Most patients received low-dose initiation because of history of opioid use disorder (83%). Low-dose initiation was completed in 54 of 71 patients (76%) after 76 attempts. Precipitated withdrawal was identified in 2 patients (2.8%). Median morphine milligram equivalents excluding buprenorphine 24 hours before low-dose initiation was 1000 mg (interquartile range, 303.5-1720.5 mg) compared with 37.5 mg (interquartile range, 0-254 mg) after reaching target dose ( P < 0.001). CONCLUSIONS: Buprenorphine was safely initiated using low-dose initiation in hospitalized patients. This was associated with significant reduction in full agonist opioids.