Cannabinoid, CB1 agonists in cervical dystonia: Failure in a phase IIa randomized controlled trial

Background: Dystonia may result from reduced GABAergic transmission in the external globus pallidus (GPe). Cannabinoid CB1 agonists enhance GABA in the GPe and may therefore reduce dystonia. Objectives: To determine the efficacy of the cannabinoid CB1 agonist, dronabinol, in cervical dystonia (CD). Methods: Nine patients with CD were randomised to dronabinol (15. mg/d)/placebo in an 8-week crossover trial. Outcome measures included TWSTRS, visual analog scale of pain, global impression of change and adverse events (AEs). Results: There was no effect of dronabinol compared to placebo on any outcome measure (all P> 0.05, n= 7). One subject withdrew due to AEs and one was lost to follow-up. Mild AEs were experienced by all. Conclusions: Short-term use of dronabinol in CD has no benefit. Despite the study limitations, cannabinoids are unlikely to be useful in the treatment of dystonia. © 2011 Elsevier GmbH.