Risk and benefit of cannabis prescription for chronic non-cancer pain.

OBJECTIVES We investigated whether cannabis usage was associated with reduced opioid usage, and the rates of opioid and cannabis use disorders among chronic pain patients who had been prescribed medical cannabis. METHODS A random sample of chronic pain patients who had license for cannabis use were interviewed by telephone about their lifetime opioid and cannabis usage. Cannabis and opioid use disorders were assessed with Portenoy's criteria. RESULTS Of the 100 participants aged 18-70 years (compliance 67% (aged >40) and 33% (aged ≤ 40y)), 76 ever used opioids. Of them, 93% decreased or stopped opioids following cannabis initiation. Ten patients (10%), 17.4% of the ≤40 y age group, met the criteria for cannabis use disorder. Compared to those who did not meet the criteria, their lifetime depression was higher (80% vs. 43.2%, respectively, P=.042), and they were less educated (12.2 ± 0.6y vs. 13.5 ± 2.1y, p = 0.05). CONCLUSIONS Cannabis usage was associated with reduced opioid usage. The prevalence of cannabis use disorder was high among the younger participants who also had a lower study compliance rate, suggesting the higher actual prevalence of cannabis use disorder. While medical cannabis may help reduce opioid use in chronic non-cancer pain patients, younger age, depression, and other risk factors should be carefully evaluated before cannabis is prescribed.