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Cannabis and Potential Opioid- and Benzodiazepine-Sparing Properties

November 18, 2019

According to ‘Australia’s Annual Overdose Report 2019’, prepared by the Penington Institute, an Australian public health research and drug policy organisation, “unintentional overdose continues to be a significant cause of death in Australia. The continued growth in unintentional overdose deaths is linked to highly potent drugs, many of which are available through prescription, such as pharmaceutical opioids and benzodiazepines”. The report is quoted as “a chronicle of the immense economic and social cost of unintentional overdose deaths in Australia”.

The report found that almost three-quarters of drug-induced deaths in 2017 were unintentional. The class of drugs that contributed to the greatest number of fatal overdoses was opioids. These are analgesics, which are used to treat pain, and include pharmaceutical medicines such as codeine, oxycodone and fentanyl, as well as illicit substances like heroin. Twenty years ago, the most common drug causing accidental death was heroin. Today, it is pharmaceutical opioids that are responsible for the majority of overdose deaths, with a strong association between increases in opioid prescriptions and increased mortality.

Benzodiazepines follow opioids in the drug group most commonly identified in unintentional drug-induced deaths. Benzodiazepines are medicines used to treat anxiety, relax people and assist with sleep, but they may also be used non-medically. When taken alone, benzodiazepines’ depressant effect on the respiratory system does not usually result in a complete loss of breathing function. When combined with other drugs like alcohol or opioids, however, their effect on respiration is increased, making concurrent use of benzodiazepines with alcohol and/or opioids especially dangerous.

A recent article published in 2019 by the Annals of Pharmacotherapy highlights the results of a 6-month retrospective study on how medical cannabis affects opioid and benzodiazepine use by patients on a daily basis. Patients using medical cannabis for intractable pain experienced a significant reduction in the number of daily MMEs (milligram morphine equivalents) for pain control.

Another 2019 article, published in Cannabis and Cannabinoid Research, reports a retrospective analysis of a cohort of patients who reported benzodiazepine use at initiation of medical cannabis therapy. Almost half (45.2%) of the cohort successfully discontinued their pre-existing benzodiazepine therapy after three courses of medical cannabis prescription.

Further prospective studies are warranted to better understand the effect of medical cannabis in these areas of great public interest.



O’Connell, M., Sandgren, M., Frantzen, L., Bower, E. and Erickson, B. (2019). Medical Cannabis: Effects on Opioid and Benzodiazepine Requirements for Pain Control. Annals of Pharmacotherapy, 53(11), pp.1081-1086.

Penington Institute (2019). Australia’s Annual Overdose Report 2019. Melbourne: Penington Institute

Purcell, C., Davis, A., Moolman, N. and Taylor, S. (2019). Reduction of Benzodiazepine Use in Patients Prescribed Medical Cannabis. Cannabis and Cannabinoid Research, 4(3), pp.214-218.