MEDICAL STUDY THROWS WATER ON MARIJUANA SMOKE

But Cannabinoids May Still Be Helpful

Marijuana is too dangerous to the lungs to make smoking 'grass' a safe
long-term treatment for illness - but some of the active ingredients
in the weed could sprout into a whole new family of medicines.

Those are among the conclusions of a landmark report issued late last
month by an expert panel on the medical uses of marijuana, a topic
that has pitted patients and pro-legalization activists against the
federal government.

Marijuana's active ingredients belong to a chemical family called the
cannabinoids. In recent years, scientists have found that these
chemicals - as well as receptors on cell surfaces that respond to
them - are found naturally in memory, control of movement and pain
perception.

Scientific knowledge of cannabinoids has exploded, far outstripping
the few well-conducted medical studies of marijuana's therapeutic
effects in patients, according to the pair of scientists who headed
the panel. Together, the new laboratory findings and clinical results
suggest that some cannabinoids could be developed into promising drugs
for pain control, the relief of nausea and vomiting and stimulation of
appetite in people who have lost weight because of AIDS or other diseases.

Just last month, the Canadian government announced it has plans to
conduct human clinical tests to determine if smoking marijuana can
reduce pain in terminally ill patients. And the movement to legalize
marijuana for this use is gaining more and more publicity. Calgarian
Grant Krieger, who has multiple sclerosis and uses marijuana to
alleviate his symptoms, is organizing a Compassion Club in the city to
provide locally grown pot to people with serious illnesses.

Some patients currently smoke or eat marijuana to treat those
problems, a situation that has produced a conflict between those who
want to legalize medical use of the drug and governments which oppose
legalization.

'There are real clinical opportunities' to develop new drugs from
cannabinoids, said Stanley J. Watson, co-director of the Mental Health
Research Institute at the University of Michigan and co-chairman of
the panel that conducted the review for the Institute of Medicine
(IOM) , an independent advisory body.

The IOM report had been eagerly awaited by both sides in the ongoing
debate over whether marijuana should be made legally available for
people with certain intractable symptoms, such as nausea caused by
chemotherapy or wasting associated with AIDS.

To the delight of many activists who have urged legalization of
medical use of the drug, the panel concluded that some of marijuanas
constituents are potentially effective therapies. Nevertheless, the
report strongly opposes the use of smoked marijuana except in
short-term scientific studies lasting less than six months, citing the
dangers posed by tar, carcinogens and other substances present in the
smoke.

'Numerous studies suggest that marijuana smoke is an important risk
factor in the development of respiratory disease' and is associated
with an increased risk of cancer, lung damage and poor pregnancy
outcomes, the report states.

'While we see a future in the development of...cannabinoids drugs, we
see little future in smoked marijuana as a medicine,' said panel
co-chairman John A. Benson, an emeritus professor of medicine at
Oregon Health Sciences University.

How might cannabinoids drugs be used? `Analgesia (pain relief) may be
the biggest market for commercial exploitation,' Benson said.

For nausea and vomiting caused by chemotherapy , cannabinoids are
mildly effective, but for most patients, neither marijuana or THC (an
active ingredient of marijuana) works as well as other anti-naseau
drugs currently available, the report found.

Marijuana has been advocated to treat a number of other conditions,
but the panel found the evidence for its benefits weak. It was not
impressed with cannabinoids' potential for treating glaucoma.
migraines or movement disorders such as Parkinson's disease of
Huntington's disease.

The report recognizes the dilemma faced by patients who have turned to
marijuana because they cannot get relief from legal medicines, and
said such patients 'will find little comfort in a promise of a better
drug 10 years from now.'

Some patients with chronic illnesses insist that marijuana has made
their symptoms bearable and has even prolonged their lives. In such
cases, if there is no alternative treatment, the panel suggested
establishing a system under which marijuana could be provided on a
compassionate basis, as an experimental drug, and patients' conditions
would be monitored closely.