Self-Reported History of Precipitated Withdrawal: A Cross-Sectional Study of People Who Use Unregulated Opioids.

OBJECTIVES

In contrast to methadone, buprenorphine is susceptible to precipitated withdrawal complicated by fentanyl in the unregulated opioid supply. The objective of this study was to examine associations between drug supply characteristics and the prevalence of precipitated withdrawal.

METHODS

We conducted a cross-sectional analysis of a cohort study during 2023-2025 among people with a lifetime history of buprenorphine or methadone treatment currently using a drug checking program. Explanatory variables included drug supply, health care, and treatment characteristics. The primary outcome was a self-reported lifetime history of precipitated withdrawal during a buprenorphine induction. Binomial linear regression models were used to calculate prevalence ratios with 95% CIs.

RESULTS

Among 234 people, 64% were men, 67% were non-Hispanic white, 41 was the median age, 94% reported a history of fentanyl use, 92% had a history of methadone treatment, and 68% had a history of buprenorphine treatment. Among those with a history of buprenorphine treatment, 29% reported precipitated withdrawal during buprenorphine inductions, of which 67% occurred when starting via outpatient pathways. Buprenorphine-associated precipitated withdrawal was slightly higher among those with recent xylazine use compared with those without (32% vs 22%, prevalence ratio: 2.10, 95% CI: 0.94, 4.67). People with recent buprenorphine inductions commonly started without clinical or social support (63%) or used standard dosing (53%).

CONCLUSIONS

Buprenorphine-associated precipitated withdrawal was commonly reported. Improved guidance and treatment approaches should be prioritized to minimize these complications, particularly in outpatient settings.