The Prevalence and Significance of Cannabis Use in Patients Prescribed Chronic Opioid Therapy: A Review of the Extant Literature

Background. Cannabis is the most widely consumed illicit drug in the United States. Its use, particularly in early initiates, is associated with subsequent development of other drug and alcohol use disorders. Objective. The authors examined the prevalence of cannabis use and the association between cannabis use and aberrant opioid-related behaviors in patients prescribed chronic opioid therapy for persistent pain. Methods. PubMed was queried for studies of chronic opioid therapy in which aberrant opioid-related behaviors were quantitatively examined and in which cannabis use data (as determined by cannabinoid-positive urine drug tests) were extricable from that of other substances of abuse. Results. The prevalence of cannabis use among patients prescribed chronic opioid therapy in these studies ranged from 6.2% to 39%, compared with 5.8% in the general United States population. Furthermore, cannabis use in chronic opioid patients shows statistically significant associations with present and future aberrant opioid-related behaviors. Conclusion. Cannabis use is prevalent in patients prescribed chronic opioid therapy and is associated with opioid misuse. Further research is necessary to clarify the strength and the nature of the association between cannabis use and opioid misuse, and to address additional questions about the consequences of cannabis use in the context of chronic opioid therapy.