Cannabis related side effects in otolaryngology: a scoping review.

BackgroundCannabis has been rapidly legalized in North America; however, limited evidence exists around its side effects. Health Canada defines side effect as a harmful and unintended response to a health product. Given drug safety concerns, this study's purpose was to review the unintended side effects of cannabis in otolaryngology.MethodsThe Preferred Reporting Items For Systematic Reviews and Meta-analysis extension for Scoping Reviews (PRISMA-ScR) protocol was used to conduct a scoping review of the MEDLINE, EMBASE, CINAHL, and CENTRAL databases. (PROSPERO: CRD42020153022). English studies in adults were included from inception to the end of 2019. In-vitro, animal, and studies with n ResultsFive hundred and twenty-one studies were screened; 48 studies were analysed. Subspecialties comprised: Head and Neck (32), Otology (8), Rhinology (5), Airway (5), Laryngology (1). Cannabis use was associated with unintended tinnitus, vertigo, hearing loss, infection, malignancy, sinusitis, allergic rhinitis, thyroid dysfunction, and dyspnea. About half (54.1%) of studies showed increased side effects, or no change in symptoms following cannabis use. Oxford Levels of Evidence was 2-4 with substantial heterogeneity. Risk of bias assessment with RoB2 was low to high and ROBINS-1 was moderate to critical.ConclusionThis was the first comprehensive scoping review of unintended side effects of cannabis in Otolaryngology. The current literature is limited and lacks high-quality research Future randomized studies are needed to focus on therapeutic effects of cannabis in otolaryngology. Substantial work remains to guide clinicians to suggest safe, evidence-based choices for cannabis use.