Opiod and Marijuana Use in Patients with Chronic Non-Cancer Pain

Date of Award

Spring 2016



First Advisor

Dr. Helen M. Murphy


Recent research suggests that marijuana may augment the effectiveness of opioid analgesics. This retrospective study examined a subset of data from a long-standing IRB registry to determine if patients using marijuana in conjunction with chronic opioid therapy used lower doses of opioids. Data were examined from 2010 – 2014 and 39 patients using marijuana were identified (verified by urine toxicology screen). Marijuana users were matched with nonmarijuana users also undergoing chronic opioid therapy based on age, gender and programadmission data. Because research suggests that patients with therapeutic opioid addiction use more opioids, patients were also matched on this basis as well. This process resulted in a sum total of 78 participants. Participants were 56.4% male with a mean age of 39.49 (±11.34) and ranged in age from 20 to 60 years old. 55.1% of patients had a therapeutic opioid addiction and 48.7% of marijuana users were diagnosed with marijuana dependence. Mean daily oral morphine equivalence dose was 139.49 (±191.73). Analysis of variance (ANOVA) showed that there was no statistically significant differences in daily oral opioid doses between marijuana and non-marijuana users (F1,76=0.99, df=1, ns; μ = 117.85 ±136.25 and μ = 161.13 ±234.44 respectively). While results demonstrated no significant difference between the two groups, it is possible that results were confounded by the presence of co-occurring therapeutic opioid disorder. Future research should be conducted prospectively, in patients without addictive disorders in order to examine if adjunctive marijuana use increases the efficacy of opioid analgesia.

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