Spasticity is a common complaint after traumatic SCI. 9–THC the main psychoactive cannabinoid of cannabis has been shown to have beneficial effects in the treatment of spasticity of different origin. The aim of the study was to assess the effectiveness and safety of 9–THC (Dronabinol, Marinol® capsules) and THC-hemisuccinate suppositories (THC-HS) for the treatment of spasticity in patients with SCI as a homogeneous population of patients. We are presenting the results of spasticity as partial results of a finished study with a wide spectrum of other investigations.
Phase 1: open trial, six weeks treatment of 22 patients with Dronabinol (7 drop outs)
Phase 2: open trial, six weeks treatment of 8 patients with THC-HS (1 drop out)
Phase 3: randomized, double-blind, placebo controlled clinical trial with 13 patients (Marinol/placebo)
25 patients mean age 42.3 years with spasticity due to SCI (11 para- and 14 tetraplegics) were included. Mean time since injury was 13.4 years. Inclusion criteria for spasticity were minimum of 3 points on the Ashworth scale without therapy, negative urine drug screening, age > 18 years.
Spasticity was investigated using the modified Ashworth scale (MAS) after administration of 10 mg Dronabinol (Marinol®) or 10 mg THC-HS at day one and after one and six weeks treatment with an individual dose. Self-rating of spasticity was performed every day using a seven point scale from absent to unbearable.
Phase 1: Dronabinol (Marinol®) significantly decreased the mean spasticity sum score (± SD) (summed Ashworth scores divided by four) in 15 patients after a single dose of 10 mg (day 1) from 16.72 ± 7.60 to 7.75 ± 7.00 points (p<0.001) and after 6 weeks of treatment with an individual symptom oriented mean dose of 30 mg Dronabinol to 8.92 ± 7.14 points (p<0.05).
Phase 2: THC-HS significantly decreased the mean spasticity sum score (± SD) in 7 patients after a single dose of 10 mg (day 1) from 22.71 ± 11.68 to 9.86 ± 8.15 points (p<0,05) and after 6 weeks of treatment with an individual symptom oriented mean dose of 43 mg THC-HS to 9.21 ± 9.25 points (p<0.05).
The comparison of oral and rectal application in five patients showed no difference.
Phase 3: summed spasticity scores for the Dronabinol group (7.21 points) differed significantly from summed scores of the placebo group (12.10 points) as a treatment effect of Dronabinol during the entire 6 weeks (p=0.001).
The results demonstrate a significant therapeutic effect of 9–THC (Dronabinol, Marinol ®) as well as THC-HS in patients with SCI. However the antispastic efficacy is significant the treatment often is limited by side effects.
The research was supported by ElSohly Laboratories Inc., Oxford, Mississippi