From the International Association for Cannabis Medicine

British researchers of the Walton Centre for Neurology and
Neurosurgery in Liverpool demonstrated that the cannabis
extract Sativex of GW Pharmaceuticals is effective in reducing
central neuropathic pain and sleep disturbance in people with
multiple sclerosis (MS). "Central neuropathic pain occurs
frequently in people with MS. It can be tremendously debilitating
and unresponsive to existing therapies," Dr Carolyn Young,
principal investigator of the study, said.

The 5 week placebo-controlled study was conducted in 66
patients with MS who suffered from chronic neuropathic pain.
64 patients completed the trial, of whom 32 received the
cannabis extract and 32 the placebo. Sativex contains equal
amounts of THC and cannabidiol (CBD) and is administered as
a spray under the tongue. The mean maximum daily THC dose
was 25 mg (range: 5-65 mg). Pain and sleep disturbance were
recorded daily on an 11-point numerical rating scale. Cannabis
caused a significant mean pain reduction of 2.7 points (baseline:
6.5) compared with 1.4 points (baseline: 6.4) following placebo.
Sleep was significantly improved by 2.5 points with cannabis
compared to 0.8 points with placebo. The cannabis extract was
generally well tolerated, although more patients on cannabis than
placebo reported dizziness, dry mouth, and somnolence.

Based on these study results, which were published now in the
journal Neurology, Sativex was approved as a prescription
medicine in Canada for the symptomatic relief of neuropathic
pain in adults with MS and is available in pharmacies since 20
June 2005.

(Sources: Rog DJ, Nurmikko TJ, Friede T, Young CA.
Randomized, controlled trial of cannabis-based medicine in
central pain in multiple sclerosis. Neurology 2005;65(6):812-9;
press release by GW Pharmaceuticals of 27 September 2005)