Cannabis use and opioid relapse: An exploratory survival analysis of prospectively collected data

Leen Naji; Tea Rosic; Nitika Sanger; Brittany Dennis; Alannah Hillmer; Jacqueline Hudson; Andrew Worster; James Paul; David C Marsh; Lehana Thabane; Zainab Samaan

doi:10.3389/fpsyt.2022.1046649

Cannabis use and opioid relapse: An exploratory survival analysis of prospectively collected data

Front Psychiatry. 2022 Nov 16:13:1046649. doi: 10.3389/fpsyt.2022.1046649. eCollection 2022.

Authors

Leen Naji^{1

2}, Tea Rosic^{2

3}, Nitika Sanger⁴, Brittany Dennis⁵, Alannah Hillmer⁶, Jacqueline Hudson⁷, Andrew Worster^{2

5}, James Paul⁸, David C Marsh⁹, Lehana Thabane^{2

10}, Zainab Samaan^{2

7}

Affiliations

¹ Department of Family Medicine, McMaster University, Hamilton, ON, Canada.
² Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada.
³ Department of Psychiatry, University of Ottawa, Ottawa, ON, Canada.
⁴ Medical Sciences Graduate Program, McMaster University, Hamilton, ON, Canada.
⁵ Department of Medicine, McMaster University, Hamilton, ON, Canada.
⁶ Neuroscience Graduate Program, Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada.
⁷ Department of Psychiatry and Behavioral Neurosciences, McMaster University, Hamilton, ON, Canada.
⁸ Department of Anesthesia, McMaster University, Hamilton, ON, Canada.
⁹ Northern Ontario School of Medicine, Laurentian University, Sudbury, ON, Canada.
¹⁰ Biostatistics Unit, Research Institute at St Joseph's Healthcare, Hamilton, ON, Canada.

Abstract

Importance: It is known that only minority of patients with opioid use disorder (OUD) receive treatment, of which only a fraction successfully complete treatment as intended. Factors associated with poor treatment outcomes remain unclear, and there is emerging but conflicting evidence that cannabis use may mitigate opioid use.

Objective: To analyze predictors of relapse amongst patients receiving buprenorphine-naloxone for OUD and identify the association between cannabis use and time to relapse.

Design: Data were prospectively collected between May 2018 and October 2020, and patients were followed for 12 months.

Setting: Thirty-one outpatient opioid agonist treatment clinics across Ontario, Canada.

Participants: All patients 16 years of age or older receiving buprenorphine-naloxone for OUD who had a urine toxicology screen negative for opioids at baseline were eligible for inclusion. Of the 488 patients consecutively sampled, 466 were included.

Exposure: Cannabis use.

Main outcome and measure: Relapse to opioid use assessed using urine toxicology screens. We employed a multivariable Cox-proportional hazard model for our analyses.

Results: We found that cannabis use was not protective against relapse [hazard ratio (HR) = 1.03, 95% confidence interval (CI): 0.78, 1.36, p = 0.84]. We found that participants who have been in treatment for at least two years had a 44% decrease in the hazard of relapse compared to those in treatment for less than a year (HR = 0.56, 95% CI: 0.34, 0.92, p = 0.021). We also found that the hazard of relapse was 2.6 times higher for participants who were intravenous drug users (HR = 2.61, 95% CI: 1.74, 3.91, p < 0.001), and that for every 1mg increase in the participants' buprenorphine-naloxone dose, the hazard of relapse is 2% greater (HR = 1.02, 95% CI: 1.01, 1.03, p < 0.001).

Conclusion: Our analysis failed to show cannabis to be protective against relapse to opioid use in patients receiving buprenorphine-naloxone for OUD. We identified that individuals who inject drugs, are on higher doses of buprenorphine-naloxone, or have been in treatment for less than two years have a higher hazard for relapse. The presence of such factors may thus warrant closer patient follow-up and more stringent treatment protocols to mitigate risk of relapse and potential overdose.

Keywords: buprenorphine; cannabis use; opioid agonist therapy; opioid use disorder; relapse.