‘Low-Dose’ Cannabidiol: An Emerging Area of Clinical Practice

Abstract

General practitioners (GPs) and pharmacists are at the frontlines of medicinal cannabis access. Evidence around the efficacy of these products being scarce causing difficulties in the practice of evidence-based medicine. Cannabidiol (CBD) is a non-intoxicating constituent of the cannabis plant and a common ingredient in medicinal cannabis products. CBD is often consumed at lower doses than those that have been proven to be therapeutic, yet the global demand for ‘low-dose CBD’ products has soared.

In this thesis, a series of original investigations were conducted to address two aims. Thesis Aim One was to explore the knowledge, experiences, and attitudes of GPs and pharmacists towards medicinal cannabis, including low-dose CBD products, by undertaking two cross-sectional studies. Overall, findings indicate that respondents tended to lack confidence and detailed knowledge in this area and required further training. Thesis Aim Two was to expand the current evidence base around the efficacy of low-dose CBD products by undertaking two clinical trials. The first was an open-label feasibility trial investigating the effects of a four-week treatment with a transdermal, low-dose CBD gel (~30 mg per day) in 15 participants with hand osteoarthritis. A significant reduction in subjective ratings of hand pain from baseline and a significant increase in grip strength over time were found. The second study was a randomised, double-blind, placebo-controlled trial that investigated the acute effects of an oral, low-dose of CBD (150 mg) on anxiety and nausea using a virtual reality test paradigm. An acute dose of 150 mg CBD reduced self-reported anxiety immediately after a virtual ‘Public Speaking’ task with no other significant effects found.

Overall, medicinal cannabis, including low-dose CBD, is having a considerable impact on clinical practice. The clinical trial results contribute to evidence around the efficacy of low-dose CBD, that will ultimately support clinical practice.