Reductions in tobacco use in naltrexone, relative to buprenorphine-maintained individuals with opioid use disorder: Secondary analysis from the National Drug Abuse Treatment Clinical Trials Network

Background: Smoking prevalence in individuals with opioid use disorder (OUD) is over 80%. Research suggests that opioid use significantly increases smoking, which could account for the strikingly low smoking-cessation rates observed in both methadone- and buprenorphine-maintained patients, even with the use of first-line smoking-cessation interventions. If opioids present a barrier to smoking-cessation, then better smoking outcomes should be observed in OUD patients treated with extended-release naltrexone (XR-NTX, an opioid antagonist) compared to those receiving buprenorphine (BUP-NX, a partial opioid agonist). Methods: The current study is a secondary analysis of a 24-week, multi-site, open-label, randomized clinical trial conducted within the National Drug Abuse Treatment Clinical Trials Network comparing the effectiveness of XRNTX vs. BUP-NX for adults with OUD. Longitudinal mixed effects models were used to determine if there was a significant reduction in cigarette use among daily smokers successfully inducted to treatment (n = 373) and a subset of those who completed treatment (n = 169). Results: Among daily smokers inducted onto OUD medication, those in the XR-NTX group smoked fewer cigarettes per day (M = 11.36, SE = 0.62) relative to smokers in the BUP-NX group (M = 13.33, SE = 0.58) across all study visits, (b (SE) = -1.97 (0.55), p < .01). Results were similar for the treatment completers. Conclusions: OUD patients treated with XR-NTX reduced cigarette use more than those treated with BUP-NX, suggesting that XR-NTX in combination with other smoking cessation interventions might be a better choice for OUD smokers interested in reducing their tobacco use.