CANNABIS CAN HELP MS SUFFERERS

Claims that cannabis can relieve the symptoms of multiple sclerosis
have been reinforced by results from the world's largest ever trial of
the medicinal effects of the drug - but only just.

The main improvements seen were in subjective measures of symptoms,
i.e. those reported by the patients, rather than in those measured
using standardised tests. Nonetheless, the study on 630 MS patients
has been greeted as providing the strongest scientific justification
yet for legalising medicines based on marijuana.

"The study does suggest that for some people, they may be of benefit,
particularly in terms of pain relief and muscle stiffness," says Alan
Thompson, at the National Hospital for Neurology and Neurosurgery in
London, UK, and co-leader of the research.

Thompson and his colleagues divided their 630 patients into three
groups. The first received D9-tetrahydrocannabinol (THC), the main
active ingredient of cannabis. The second group received a cannabis
plant extract, and the third a placebo.

Muscular Stiffness

The investigators particularly wanted to find out whether the drugs
could ease symptoms of spasticity, the muscular stiffness and jerky
movements that afflict patients with MS.

Standard objective tests to measure the severity of spasticity
suggested the drugs were no more effective than the placebo. But 60
per cent of treated patients reported a reduction in spasticity,
compared with 46 per cent who received the placebo.

Furthermore, 54 per cent of the treated patients reported pain relief
compared with 37 per cent receiving the placebo. "This suggests
cannabinoids may benefit some patients," says Thompson. However, the
researchers note some of the patient's receiving cannabis became
"light-headed", meaning they realised they were receiving the drug
rather than the placebo - which might affect the subjective ratings.

But the UK Multiple Sclerosis Society says the results reinforce the
need for researchers to focus as much on how patients say they feel as
on what the tests measure. The society is calling for cannabis-based
drugs of proven benefit to be made available through the UK's National
Health Service.

Evidence Base

In a commentary on team's paper in The Lancet, Luanne Metz and Stacey
Page, at the University of Calgary, Canada, note: "We now have as much
evidence to support the use of these oral cannabinoids - as we do for
many standard therapies for spasticity."

The UK's National Institute for Clinical Excellence is evaluating the
potential for cannabis-based medicines, but its advice is not expected
next June.

Britain's drug approval authorities are also midway through evaluating
an application to sell a cannabinoid-based painkiller. If it is
approved, the government has promised to amend the law classifying
marijuana as an illegal drug to allow the medicine based on it to be
given legally.

In the meantime, the researchers have warned patients against smoking
marijuana to relieve symptoms. "The major problem with smoking is
making sure you know how much active component is in the blood, and
the second problem is the cancer risk," says Thompson.

Journal reference: The Lancet (vol 362, 1517)