Objective: To determine if cannabidiol (CBD) is tolerated and effective in Parkinson disease (PD) and the dosage needed for a Phase 2 randomized controlled trial.   

Background: Although there is no conclusive data on the use of cannabis in PD, many patients take various formulations and use is becoming more widespread as it becomes more available in the US. Literature suggests that CBD may be well tolerated and efficacious in PD. 

Methods: This is an open label, dose-escalation study in persons with idiopathic PD and intractable tremor. CBD (Epidiolex, purified CBD from GW Pharmaceuticals) is started at 5 and increased gradually to 25 mg/kg/day or to a lesser but maximum tolerated dose. Prior studies of Epidiolex in pediatric epilepsy suggest that 25 mg/kg/day has a CNS effect. The primary outcome, tolerability and safety, is evaluated by adverse events and clinical data. The secondary outcomes, regarding efficacy, are assessed with standardized tests on motor and non-motor symptoms of PD. 

Results: Six subjects, mean age (SD) 69.8 (4.7), were enrolled from Oct 17 to Dec 29, 2016. Five were male, total MDS Unified PD Rating Scale (UPDRS) score was 32.5 (8.5) and Hoehn & Yahr 1.75 (0.4). The average period of time on treatment was 27 days. All subjects reported adverse events: diarrhea (n=4[67%]), fatigue (n=4[67%]), somnolence (n=3[50%]), dizziness (n=3[50%]), abdominal pain (n=2[33%]) and elevated liver enzymes (n=2[33%]). The elevated liver enzymes, one marked and one mild, both transient, occurred in persons on concomitant treatment that may have contributed. Flatulence, eructation, decreased appetite, headache, insomnia, chills, rash and spasm were also reported (each n=1[17%]). Adverse events were more frequent at higher doses and most were mild to moderate. Three subjects stopped study drug due to intolerability: due to rash on 5 mg/kg, due to abdominal pain and flatulence on 17.5 mg/kg and due to fatigue, diarrhea and elevated liver enzymes on 25 mg/kg. There were no serious adverse events. While the three subjects that completed the study had improvements in MDS UPDRS and SCOPA-SLEEP night scores and subjective improvements in tremor, anxiety and pain, there were no significant findings regarding efficacy. 

Conclusions: Cannabis research is needed. This study focuses on CBD and is limited by a small number of subjects. Further data is needed to determine the dosage and its safety and tolerability in PD. This will enable conduct of a randomized blinded study. 

« Back to 2017 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/open-label-study-of-cannabidiol-in-parkinson-disease/