Cannabidiol drug interaction considerations for prescribers and pharmacists

In light of the widespread use of non-prescribed and prescribed cannabidiol, the use of cannabidiol with other medications is likely, and this may result in drug interactions.

We aimed to ascertain if clinical guidance could be provided on the dose range at which cannabidiol drug interactions are likely to occur with concurrently prescribed medicines. Literature searches were conducted in Embase, MEDLINE, and PubMed from database inception to January 2022 using Emtree and MeSH terms. Reference list screening yielded further studies. Using currently available data, likely drug interactions of which prescribers of cannabidiol need to be aware, at the doses likely to cause clinically significant interactions, and drug dosing changes that may be needed are highlighted.

We have provided an overview of evidence-based pharmacokinetic predictions and general guidance about the dose range at which clinically relevant cannabidiol drug interactions are likely. For an individual patient, there are inherent limitations in providing clinical guidance due to gaps in specific drug dose-response data and knowledge of individual pharmacokinetic profiles, including different co-morbidities, and concurrent medicines. Clinician awareness of cannabinoid pharmacology, along with clinical and therapeutic drug monitoring, are current best practice approaches to manage cannabinoid drug interactions.