Update on Cannabidiol Clinical Toxicity and Adverse Effects: A Systematic Review

Area of Science:

• Pharmacology
• Clinical Toxicology
• Cannabinoid Research

Background:

• Preclinical and clinical evidence supports cannabidiol's (CBD) therapeutic potential.
• Previous reviews in 2019 highlighted uncertainties regarding CBD's safety and adverse events (AEs).
• An updated assessment of CBD toxicity and AEs in humans is crucial given the rise in clinical studies.

Approach:

• A systematic literature search adhering to PRISMA guidelines was performed.
• Clinical studies published between February 2019 and September 2022 were identified via PubMed, Cochrane, and Embase.
• Data on study design, patient demographics, CBD dosage, treatment duration, co-medications, and reported AEs were systematically compiled.

Key Points:

• Fifty-one reports were analyzed, primarily focusing on neurological conditions like epilepsy, with increasing research in substance use disorders, psychosis, and anxiety.
• Most reported AEs were mild to moderate, commonly including diarrhea, somnolence, sedation, and upper respiratory issues.
• Serious AEs were infrequent, particularly when CBD was used alongside other medications such as clobazam and valproate.

Conclusions:

• Current clinical data indicate that cannabidiol (CBD) is well-tolerated at therapeutic doses in both pediatric and adult populations.
• Few serious adverse events (AEs) are associated with CBD use, though careful monitoring for drug interactions is essential.
• Further research is required to establish long-term CBD efficacy and safety, and to explore its use in conditions beyond epilepsy syndromes.