Methadone vs Buprenorphine for Reduced Overdose Risk, Treatment Retention

Buprenorphine was associated with reduced overdose risk but lower rates of treatment retention compared to methadone among patients with opioid use disorder. Researchers published their findings in Addiction.

The population-based propensity-score matched cohort study was conducted in Ontario, Canada. Patients were at least 18 years of age and began treatment with methadone or buprenorphine/naloxone between October 2016 and December 2018. There were 7,517 participants in each cohort.

The buprenorphine cohort had a lower risk of overdose throughout the treatment period (HR .5; 95% CI .37-.68) as well as within the first 30 days of treatment (HR .51, 95% CI .31-.85). People receiving buprenorphine also interacted less with the health care system for opioid use disorder (186.5 vs 254.4 per person-year; Rate Ratio .73; 95% CI .72-.75) and received weekly take-home doses at a higher rate (HR 2.33; 95% CI 2.20-2.46).

However, buprenorphine was associated with higher risk of treatment discontinuation within the first year compared to methadone (median time to discontinuation 104 vs 265 days, HR 1.43, 95% CI 1.37-1.49).

“Although treatment retention is higher among methadone recipients, overdose risk is also elevated compared to buprenorphine recipients,” authors said.

Overdose rates were higher when patients discontinued treatment, but rates were not significantly different between each type of opioid agonist therapy (OAT).

These findings demonstrate the benefits of any OAT on avoidance of overdose, particularly following treatment discontinuation and with the increasingly unpredictable drug supply in North America,” researchers concluded.

Reference:
Gomes T, McCormack D, Bozinoff N, et al. Duration of use and outcomes among people with opioid use disorder initiating methadone and buprenorphine in Ontario: A population-based propensity-score matched cohort study. Addiction. Published online ahead of print March 8, 2022. doi:10.1111/add.15862