Abuse potential assessment of cannabidiol (CBD) in recreational polydrug users: A randomized, double-blind, controlled trial.

RATIONALE: Treatment with a highly purified oral solution of cannabidiol (CBD), derived from the plant Cannabis sativa L., demonstrated some evidence of central nervous system (CNS)-related adverse events in patients enrolled in phase 3 trials for treatment of childhood-onset epilepsy. Cannabidiol was categorized as a Schedule 1 substance by the United States Drug Enforcement Administration; therefore, it was important to test CBD for human abuse potential. METHODS: This was a single-dose, randomized, double-blind, double-dummy, placebo- and active-controlled crossover trial. The abuse potential of single oral doses of plant-derived pharmaceutical formulations of highly purified CBD (Epidiolex®; 750 mg, 1500 mg, and 4500 mg) was compared with that of single oral doses of alprazolam (2 mg), dronabinol (10 mg and 30 mg), and placebo in healthy recreational polydrug users. The primary endpoint to assess abuse potential was the maximum effect (Emax) on Drug-Liking visual analog scale (VAS). Other measurements included Emax on Overall Drug-Liking VAS, Take Drug Again VAS, positive and negative effects, other subjective effects, and Drug Similarity VAS. Cognitive and psychomotor functions were assessed using the Divided Attention Test, the Hopkins Verbal Learning Test-Revised, and the Digit-Symbol Substitution Task. Pharmacokinetic parameters were determined for CBD and its major metabolites. Standard safety measures and adverse events were assessed. PRINCIPAL RESULTS: Of 95 eligible subjects, 43 qualified for the treatment phase, received at least 1 dose of investigational medicinal product, and were included in safety assessments; 35 subjects were included in the pharmacodynamic analysis. Subjects receiving alprazolam and dronabinol had significantly higher Drug-Liking Emax (P < 0.0001) compared with those receiving placebo, confirming study validity. Compared with placebo, Drug-Liking was not significantly different for subjects taking 750-mg CBD (P = 0.51). Drug-Liking Emax values for 1500-mg and 4500-mg CBD were significantly different from placebo (P = 0.04 and 0.002, respectively); however, the mean differences were <10 points on VAS compared with >18-point differences between positive controls and placebo. Alprazolam and dronabinol had significantly higher Drug-Liking, Overall-Liking, and Take Drug Again VAS Emax values compared with all doses of CBD (P ≤ 0.004). In contrast to alprazolam, CBD administration had no observable effect on cognitive/psychomotor tests. Pharmacokinetic parameters for CBD in this trial were consistent with previous studies. The majority of adverse events reported during the trial were of mild or moderate severity; no serious adverse events or deaths were reported. CONCLUSION: Administration of a therapeutic dose of CBD (750 mg) showed significantly low abuse potential in a highly sensitive population of polydrug users. Although high and supratherapeutic doses of CBD (1500 mg and 4500 mg, respectively) had detectable subjective effects compared with placebo; the effects were significantly lower than those observed with alprazolam and dronabinol.

An observational postmarketing safety registry of patients in the UK, Germany, and Switzerland who have been prescribed Sativex® (THC:CBD, nabiximols) oromucosal spray.

The global exposure of Sativex® (Δ9-tetrahydrocannabinol [THC]:cannabidiol [CBD], nabiximols) is estimated to be above 45,000 patient-years since it was given marketing approval for treating treatment-resistant spasticity in multiple sclerosis (MS). An observational registry to collect safety data from patients receiving THC:CBD was set up following its approval in the UK, Germany, and Switzerland, with the aim of determining its long-term safety in clinical practice. Twice a year, the Registry was opened to prescribing physicians to voluntarily report data on patients' use of THC:CBD, clinically significant adverse events (AEs), and special interest events. The Registry contains data from 941 patients with 2,213.98 patient-years of exposure. Within this cohort, 60% were reported as continuing treatment, while 83% were reported as benefiting from the treatment. Thirty-two percent of patients stopped treatment, with approximately one third citing lack of effectiveness and one quarter citing AEs. Psychiatric AEs of clinical significance were reported in 6% of the patients, 6% reported falls requiring medical attention, and suicidality was reported in 2%. Driving ability was reported to have worsened in 2% of patients, but improved in 7%. AEs were more common during the first month of treatment. The most common treatment-related AEs included dizziness (2.3%) and fatigue (1.7%). There were no signals to indicate abuse, diversion, or dependence. The long-term risk profile from the Registry is consistent with the known (labeled) safety profile of THC:CBD, and therefore supports it being a well-tolerated and beneficial medication for the treatment of MS spasticity. No evidence of new long-term safety concerns has emerged.