SMOKING CURE ON TRIAL

Vanessa Houlder on a research programme that could lead to a currently
illegal drug being cleared for medicinal use.

Rarely has a new research programme caused such a stir. When last week the
UK Government gave the go-ahead to a cannabis farm that would grow plants
for the first large-scale clinical trials of the drug, it seemed to signal
an important change in attitude.

There is now the political will to approve cannabis as a drug, in the view
of Geoffrey Guy, the pharmaceutical entrepreneur behind the initiative. Four
years ago, his request to conduct a similar programme received a frosty
response.

The government's opposition to legalising the drug is unchanged. But its
willingness to approve research into its medical applications reflects
mounting pressure from doctors who are convinced of its potential benefits.
For example:

* Earlier this month, an independent study commissioned by the Department
of Health found "good evidence" that cannabinoids - the active constituents
of cannabis - reduce nausea in patients taking chemotherapy. The review,
conducted by Dr Philip Robson of Warneford Hospital in Oxford, found that
cannabinoids may be effective in relieving muscle spasms, pain, anxiety,
insomnia, certain forms of epilepsy, glaucoma and asthma. It would be
"irrational" not to ex-lore he therapeutic uses of cannabis further through
properly-controlled human research, it said.

* Last year both the British Medical Association and the US Institutes of
Health issued reports which recommended more research. Potential uses
include treating AIDS patients with wasting disease, in treating glaucoma,
the eye disease, and for relieving pain and spasms in multiple sclerosis.

* Last week, the royal Society and the Academy of Medical Science jointly
submitted a report to the House of Lords enquiry into the use of cannabis,
which found it may be clinically effective in some medical conditions.

One point is repeatedly made in these studies. As the Royal Society puts
it: "It is suggested that the issues of clinical use of cannabis should be
uncoupled from the issue of recreational use."

In recent years, the legal and moral issues surrounding cannabis have tended
to obscure its medical benefits. But at one time, cannabis was highly
respectable. It was prescribed for Queen Victoria by her personal
physician, who once described it as "one of the most valuable medicines we
possess." It continued to be prescribed in tincture form by doctors in the
UK until the 1970's.

Its withdrawal from medical use stemmed partly from the development of
synthetic drugs and partly from amoral backlash against the relaxed
attitude to drugs in the 1960's. In 1971, the UK Misuse of Drugs Act listed
it as a Schedule 1 drug with no therapeutic benefits.

The moral objections to using cannabis as a medicine remain. In the US,
anti-drug lobbyists are deeply sceptical about attempts to legalise the
medical use of cannabis, such as the successful campaign in California in
1996. They are concerned that allowing the medical use of cannabis will
open up a free-for-all and that, in particular, it will encourage
experimentation by teenagers.

Another argument repeatedly put forward by anti-drugs campaigners is that
THC (a chemical known as Tetrahydrocannabinol or Marinol that is one of the
active ingredients) is already available for specific conditions, such as
the nausea associated with chemotherapy.

"If pot is such a wonderful medicine, why haven't more doctors prescribed
Marinol, the real 'medical marijuana'?" asks Barry McCaffrey, the head of
the US government's anti-drugs campaign. "The argument that his chemical
needs to be smoked, exposing patients to carcinogenic agents that damage the
lungs, doesn't make sense."

The question of whether cannabinoids can help patients more safely and
efficiently than cannabis goes to the heart of this debate. The problem
with available cannabinoids such as Marinol is that patients often say that
they get a slower and less effective response than from smoking herbal
cannabis. Scientists believe that extracting a single cannabinoid does not
replicate the effect of the whole cannabis plant, which contains more than
400 chemical compounds and over 60 cannabinoids.

When it comes to judging the safety of cannabis-based drugs, much depends on
how they are administered. Three times as much tar is inhaled from a joint
containing only herbal cannabis than an ordinary cigarette, according to the
BMA. People who suffer life-long conditions such as multiple sclerosis need
to know more about potential long-term health risks, such as lung cancer,
emphysema and bronchitis.

This means that finding other methods of administering cannabis-based
drugs - such as aerosols or skin patches - is a priority for researchers,
such as GW Pharmaceuticals, the company that was granted a research licence
by the Home Office last week.

The success of this research project, or others like it, would doubtless be
welcomed by anti-drug campaigners, as well as by patients. But research
takes time. And meanwhile, thousands of otherwise law-abiding citizens will
resort to illegal cannabis to alleviate symptoms that are poorly controlled
by existing drugs.

The debate about the medical use of cannabis is now moving on to the issue
of whether these patients should have to worry about the law. Some strands
of medical opinion already believe they should not. As Dr Robson, the
author of the Department of Health report puts it, prescribing
"compassionate reefers" to certain patients is justified on existing
evidence.

Checked-by: "Rolf Ernst"