BMJ: Trial shows no clear benefit from cannabis for patients with MS

To: talk.politics.drugs,uk.politics.drugs,sci.med.cannabis

http://bmj.bmjjournals.com/cgi/content/full/327/7424/1128

BMJ  2003;327:1128 (15 November), doi:10.1136/bmj.327.7424.1128 

News

Trial shows no clear benefit from cannabis for patients with MS 

Owen Dyer 
London 

The three year CAMS (cannabis in multiple sclerosis) trial, involving more than
600 patients in the United Kingdom, has yielded no definitive verdict on
whether the drug can ease the symptoms of multiple sclerosis. The study, funded
by the Medical Research Council, was published in last week's issue of the
Lancet ( 2003;362: 1517-26)[CrossRef]. 

Fifteen weeks' treatment with oral capsules containing either whole cannabis
extract or tetrahydrocannabinol (THC), the drug's principal active ingredient,
did not produce a significant improvement in spasticity as measured by the
widely used Ashworth scale. 

But in face to face interviews, patients assigned to the treatment arm of the
double blinded trial were more likely than those receiving placebo to report a
subjective improvement in symptoms. The participants reported significant
improvements in pain, sleep quality, spasms, and spasticity, though not in
irritability, depression, tiredness, tremor, or energy. The researchers found
that patients taking the cannabis derivative showed an improvement in the time
taken to walk 10 metres. 

The proportion of patients reporting improvements in spasticity was 61% in the
arm receiving cannabis extract (n=121, 95% confidence interval 55% to 68%), 60%
in the arm receiving THC (n=108, 53% to 67%), and 46% (n=91, 39% to 53%) in the
placebo arm. 

The lead researchers, John Zajicek, consultant neurologist at Plymouth
Hospitals NHS Trust, and Professor Alan Thompson, consultant neurologist at the
National Hospital for Neurology and Neurosurgery, London, cautioned that about
three quarters of the patients given cannabis had guessed they were taking
active medication, and half of those receiving placebo had guessed that they
were not receiving cannabis. 

Dr Zajicek said: "The primary aim of the trial was to measure, as objectively
as possible, the actual physical changes in limb spasticity in MS patients, and
we found no evidence of this. 

"Although we based the study around spasticity, we also wanted to capture any
treatment effects among the other important symptoms described by people with
MS. When patients were asked to describe how they felt that their symptoms,
including spasticity, had been affected, the picture was very different. They
felt some of the impact of their painful and distressing symptoms had been
eased. 

"We did see a high placebo effect in this trial and it may be indicative of how
much patients gain by taking part in clinical trials, irrespective of the
treatment they are given. Patients experienced very few side effects from the
treatments, and, given that how a patient feels is an important part of
improving health, cannabis based treatments may be of benefit to some
patients." 

Mike Barnes, professor of neurological rehabilitation at the University of
Newcastle, said: "The results of this study are mixed, but the positive aspects
undoubtedly outweigh the negatives. It is my hope that in the near future,
people with MS will have access to cannabis derived medicines on the NHS." 

-- 
Phil Stovell
South Hampshire, UK