According to researchers from McMaster University and St. Joseph’s Healthcare Hamilton, the use of cannabis may affect treatment in women being treated with methadone. Findings from the study are published in Biology of Sex Differences.

Researchers reported that about 60% of men and 44% of women undergoing methadone therapy also use cannabis. The study included 777 participants from 16 Canadian Addiction Treatment Centre Sites across Ontario. The results indicated women undergoing methadone treatment who used cannabis were 82% more likely to continue using opioids. Cannabis use appeared to be a “predictor for continuing opioid usedespite treatment with methadone.”  

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Senior author, Dr. Zena Samaan, concluded, “Tailoring treatment to the patient’s sex can help us to assess the patient’s risk better and deliver more accurate, personalized treatment.” Clinicians are encouraged to screen for cannabis and use the results to better map out a treatment plan and resource allocation. 

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