Medicinal cannabis as a potential treatment for chronic pain and anxiety

Abstract

Since its legalisation in Australia in 2016, the most common indications for which medicinal cannabis is prescribed are chronic pain and anxiety. This thesis aimed to explore the real-world use of cannabis for these indications, and the potential of translating this evidence into a clinical trial setting.

The effectiveness and tolerability of medicinal cannabis for chronic pain, with a subset analysis on arthritis was explored using data from the CA Clinics Observational Study (CACOS). The chronic pain patients and arthritis subset reported significantly reduced pain intensity, with dry mouth, somnolence, and fatigue the most common AEs reported.

The incidence of AEs in this cohort, and the association that these may have with concomitant medicines, cannabis constituents, and dose was also reported. Each patient was taking a median of six concomitant medications. Patients taking a gabapentinoid were more likely to report dizziness, and those taking a tricyclic antidepressant were more likely to report somnolence and anxiety.

Next in this thesis clinical trial protocols were developed, the first to examine the efficacy of a transdermal CBD cream on patients with osteoarthritis. The second protocol follows a review on aromatase inhibitor associated-arthralgia, and proposes an oral CBD-extract to improve joint pain and health-related quality of life (HRQoL).

Finally, use of cannabis for anxiety was reviewed and the effectiveness and tolerability of cannabis for anxiety, including post-traumatic stress disorder (PTSD) was explored using CACOS data. Significantly reduced anxiety was observed in patients with unspecified anxiety and PTSD, and the most common AEs reported were dry mouth, somnolence, and fatigue.

The observed improvements in various HRQoL outcomes in both the chronic pain and anxiety cohorts, and the possible safety concerns raised in this thesis supports ongoing exploration of medicinal cannabis in clinical trial settings.