Gregory 2025: how often buprenorphine triggers sudden withdrawal

What they tested

Precipitated withdrawal is a sudden, intense withdrawal that can happen when buprenorphine is started while other opioids are still in the body. The reviewers searched Medline, Embase and Cochrane CENTRAL up to 10 November 2023 for studies reporting how often it happened with buprenorphine taken under the tongue.

They included 21 cohort studies, which follow groups of people over time, and 5 randomized trials, with 4,497 participants in total. Studies ranged from 20 to 1,293 people.

What they found

The overall incidence of precipitated withdrawal ranged from 0 to 13.2% across studies. Only nine studies defined precipitated withdrawal, and their definitions didn't match.

Most patients used heroin at the start. The most common first dose of buprenorphine was between 2 mg and 8 mg, and the minimum starting score on the Clinical Opiate Withdrawal Scale (COWS) ranged from 5 to 13. Starts took place at home, in hospital, in emergency departments, before reaching hospital, in outpatient clinics and in residential units.

Of the fifteen studies with cases of precipitated withdrawal, nine didn't report how severe it was. The overall quality of the included studies was poor.

Limits

• Study quality was poor overall, and definitions of precipitated withdrawal varied from study to study.
• Most people in the studies used heroin. The site's precipitated withdrawal guide cites separate survey data suggesting recent fentanyl use raises the risk.
• Many studies with cases didn't report how severe the withdrawal was.

What it means if you're considering naltrexone

Naltrexone can also trigger precipitated withdrawal if opioids are still in the body, as the site's precipitated withdrawal guide explains. This review covers buprenorphine only and gives no figures for naltrexone, but it helps set expectations for people comparing how hard it is to start each medicine.