According to an open label clinical study conducted at the REHAB in Basel, Switzerland, THC was effective in reducing spasticity in 25 patients with spinal cord injury. In three study phases patients received oral THC, rectal THC-hemisuccinate (THC-HS) and/or placebo, each for six weeks. Originally, it was planned to start with an open phase with oral THC followed by an open phase with rectal THC-HS and then a three-way crossover placebo-controlled phase with oral THC and rectal THC-HS. Due to logistical problems with the import of THC- HS Phase 2 had to be stopped after inclusion of seven patients. Phase 3 was changed to a parallel study with oral THC and placebo.

Phase 1 was completed by 15 patients with a reduction in the mean spasticity sum score from 16.7 at baseline to 8.9 on day 43. Mean maximal daily doses were 31 mg oral THC. Reductions with rectal THC-HS were similar (Phase 2) as with oral THC. However, doses were higher with mean maximal doses of 43 mg THC-HS. It was possible to compare seven subjects who received oral THC in Phase 1 and placebo in Phase 3 demonstrating a significant improvement following the cannabinoid.

Major reasons for drop out were increase of pain and psychological side effects. Authors concluded that "THC is an effective and safe drug in the treatment of spasticity. At least 15- 20 mg per day were needed to achieve a therapeutic effect."

The abstract is available at: http://www.cannabis-med.org/studies/study.php

(Source: Hagenbach U, Luz S, Ghafoor N, Berger JM, Grotenhermen F, Brenneisen R, Maeder M. The treatment of spasticity with Delta(9)-tetrahydrocannabinol in persons with spinal cord injury. Spinal Cord. 2006 Oct 17; [Electronic publication ahead of print])