Importance: Buprenorphine treatment of opioid use disorder (OUD) is safe and effective, but opioid withdrawal during treatment initiation is associated with poor retention in care. As fentanyl has replaced heroin in the drug supply, case reports and surveys have indicated increased concern for buprenorphine-precipitated withdrawal (PW); however, some observational studies have found a low incidence of PW.

Question: What is the incidence of buprenorphine-precipitated opioid withdrawal among patients with opioid use disorder (OUD) and fentanyl use who complete traditional or high-dose buprenorphine initiation?

Findings: In this cohort study of 226 adult emergency department or hospitalized patients with opioid withdrawal severity documented within 4 hours of buprenorphine initiation, 12% developed precipitated withdrawal.

Meaning: The findings suggest that a minority of persons using fentanyl are at risk of buprenorphine-precipitated withdrawal when starting OUD treatment and that additional research is needed to identify risk factors for precipitated withdrawal.