“Background: Pain is common in Parkinson’s disease (PD), but effective therapies are limited.

Objectives: To determine the maximum tolerated dose (MTD) and safety of formulations of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) for pain in PD.

Methods: In this phase 1b, double-blind, randomized, single-center study, participants were randomized to three formulations of THC/CBD (18:0, 10:10, and 1:20). The MTD, adverse events (AE), and tolerability are described for each formulation.

Results: Eight participants were randomized. The MTD was similar among groups (0.8-0.9 mL/daily), and there were no serious AE or study drop-outs. The most common AE were drowsiness and dizziness (three participants). Epworth sleepiness scale scores were higher in the high CBD formulation (1:20).

Conclusions: In patients with pain and PD, mixed formulations of THC/CBD were tolerated with no serious AE. Considering the safety profile, future phase II studies should be considered.”

https://pubmed.ncbi.nlm.nih.gov/37476317/

https://movementdisorders.onlinelibrary.wiley.com/doi/10.1002/mdc3.13754