A Systematic Review of Medical Cannabinoids Dosing in Human

Purpose: This systematic review assesses currently available clinical information on which cannabinoids and what range of doses have been used to achieve positive effects in a diversity of medical context. Methods: The data were collected according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol guidelines. Inclusion criteria were articles that assessed administration of any cannabinoid to any clinical population, reported in the ClinicalTrials.gov or PubMed databases, that involved a comparison with other treatment or placebo and a result measurement to assess the effectiveness or ineffectiveness of the cannabinoid. Exclusion criteria were review or letter; articles not in the English language; not full-text articles; not a clinical trial, case report, case series, open-label trial, or pilot study; administration in animals, in vitro, or in healthy participants; cannabinoids administered in combination with other cannabinoids (except for cannabidiol [CBD] or tetrahydrocannabinol [THC]) or as whole cannabis extracts; no stated concentration; inhalation or smoke as a route of administration; and no results described. The articles were assessed by the risk of bias. Finding: In total, 1668 articles were recovered, of which 55 studies met the inclusion criteria for 21 diseases. Positive effects were reported in clinical studies: 52% with THC (range, 0.01–0.5 mg/kg/d [0.62–31 mg/d]), 74% with CBD (range, 1–50 mg/kg/d [62–3100 mg/d]), 64% with THC-CBD (mean, 1:1.3 mg/kg/d [ratio, 1:1]), and 100% with tetrahydrocannabivarin (THCV) (0.2 mg/kg/d). Implications: THC, CBD, and THCV can regulate activity in several pathologies. New studies of cannabinoids are highly encouraged because each patient is unique and requires a unique cannabinoid medication.