Turn on, tune in, get well

Marijuana as medicine? Tough-on-drugs America is finally coming
round to the idea that the evil weed might do some patients a power of
good.

(large photo of Dennis Peron with smoking pipe, smile, and
caption: "Celebration: Dennis Peron led California's campaign for
cannabis on prescription.")

IF you're old enough to remember peace and love and bellbottoms,
then America's latest debate on marijuana will have a familiar ring to it.
What's new is that the government might be comingsomewhat
reluctantlyto the conclusion that marijuana could make good
medicine.

Last month, at the request of the US National Institutes of
Health, a group of experts spent two days reviewing all the evidence.
After scrutinising the few scientific studies that have been done, and
listening to doctors and their patients who say they have benefited from
the drug, the panel concluded that marijuana could be useful for
treating glaucoma, nausea brought on by chemotherapy, AlDSrelated
wasting, and the symptoms of other diseases.

The debate about the healthy and harmful effects of marijuana
has rumbled on for years, but in the US it intensified in November
when voters in Arizona and California approved controversial measures
that would allow people to smoke marijuana legally on their doctor's
orders. The federal government's response was to remind doctors that
prescribing pot was still illegal under federal law and that any who do
risk losing their medical licence and perhaps a spell in prison.

Anecdotal evidence

Faced with the controversy, Harold Varmus, head of the NIH, called
for a workshop to examine the evidence. While the expert panel's
conclusions have no official force, they are a victory for advocates of
the drug, who see them as ammunition against the official government
line that marijuana has no medicinal uses. On the other hand, the panel
did not explicitly endorse the drug. Instead, it recommended that more
research should be carried out.

"The major problem here is getting good scientific data," says
William Beaver, a pharmacologist at Georgetown University in
Washington DC and chairman of the workshop panel. "You can argue
policy and politics all you want, but if you haven't got the data then
the politics make no sense. For at least some of the potential
indications, the data are good enough to recommend that new
controlled studies be done."

There is no shortage of anecdotal evidence for the weed's
therapeutic powers. The panel heard from people who said marijuana
had helped their glaucoma, prevented nausea and eased painful muscle
spasms associated with multiple sclerosis. But properly controlled
studies to confirm any of these claims are few and far between. There
was a brief flurry of research in the 1970s, when society seemed to be
growing more tolerant towards the drug, but that ended with the
election of President Reagan in 1980 and the return to a gettough
policy on drugs of all kinds.

One of marijuana's better known side effectsas an appetite
boosterhas increased the pressure to legalise the drug
for medical use. Many AIDS patients battling the deadly wasting that
can be caused by the disease smoke marijuana to stimulate their
appetites. This has made the drug a cause celebre for America's
powerful and wellorganised AIDS activists.

"There is a clear consensus that marijuana has a positive effect
on appetite," says Richard Mattes, professor of nutrition at Purdue
University in Indiana. But it is uncertain whether a healthier appetite
actually leads to weight gain: after a sudden increase in food intake, the
body may simply compensate by dulling the appetite when the drug's
effects wear off. Studies of small groups of patients have shown that
they do gain some weight but they do not specify whether it was useful
weight in the form of lean body mass such as muscle.

There are also question marks over how helpful marijuana is at
preventing nausea. Studies in the 1970s showed that the drug clearly
does have antiemetic effects says Richard Gralla director of the
Ochsner Cancer Institute in New Orleans. But the effect seems to be
weak compared with recently developed drugs which work well for
most chemotherapy patients.

Even with these drugs there may still be a place for marijuana.
However good a drug there are always some people who do not
respond to it and for them smoking marijuana might help. The same
argument applies for patients with glaucoma a blinding disease caused
by too much pressure inside the eye.

The original enthusiasm for marijuana as a glaucoma treatment
dates back to the 1970s before a number of effective drugs came onto
the market says Paul Kaufman professor of ophthalmology at the
University of Wisconsin. But in this case he says those few studies that
have been done suggest that marijuana might be just as effective as the
newer drugs and again could help those for whom these new treatments
don t work.

Marijuana might also bring relief to patients suffering muscle
spasms associated with multiple sclerosis Huntington's disease and
Tourette's syndrome. In one small study five patients with MS showed
mild to moderate improvement says Paul Consroe a pharmacologist at
the University of Arizona.

Conducting the necessary trials of marijuana is likely to prove
difficult for both political and medical reasons. Simply setting up a
trial that tests marijuana against a placebo is a challenge. Patients are
not supposed to know whether they are receiving the drug or a placebo and
it will be hard to produce a dummy drug that fools anyone who has
ever tried marijuana.

Testing a drug that is smoked also causes problems.

Therapeutically administering the drug this way has advantages: the
drug reaches the bloodstream almost immediately. Smoking also allows
patients to regulate their dose themselves by controlling the size of each
puff and how long they hold it in the lungs. But this is not accurate
enough for a controlled study that aims to find out the precise effect of
a specific dose.

On the other hand efforts to deliver the drug in the form of a
pill have not always been satisfactory. The main psychoactive ingredient
in marijuana is delta9tetrahydrocannabinol (THC) which is legally
available in capsule form. But THC given this way takes longer to reach
the bloodstream and with fixed amounts in a capsule it doesn t allow
the patient to adjust the dose so precisely. Some patients prefer the
smoked version because they can stop as soon as they begin to feel its
benefits but before they feel stoned something that is often impossible
with capsules.

Psychoactive mix

It is also possible that delta9THC is not the only chemical in
marijuana that contributes to the medicinal effect. Although THC is the
major psychoactive compound in marijuana the plant contains some
460 other compounds including 60 other chemically related
cannabinoids.

But the real problem marijuana researchers face is a political
one. The promarijuana lobby claims that the National Institute on Drug
Abuse has been unwilling to fund studies into the therapeutic effects of
marijuana because it undermines its message that pot is bad for you.

The NIDA is also the only legal source of marijuana for
medical studies and anyone wanting supplies must have the agencys
approval. Donald Abrams of the University of California San Francisco
has tried for almost five years to win approval to study the drug s effect
on AIDS wasting.

Abrams's university review committee and the Food and Drug
Administration approved his study. But when he tried to acquire the
drug the NIDA turned him down. Abrams says that the NIDA judged
the study by harsher standards than normal. I just think everybody has
a political agenda. It s hard to retain scientific objectivity he says.

As its name suggests the NIDA sees marijuana mostly in terms
of its potential for abuse and many observers claim this colours its
judgment on which studies should be done. The NIDA will only fund
research that tries to show the harmful effects of the drug says Rick
Doblin a spokesman for the Multidisciplinary Association for
Psychedelic Studies a pressure group in North Carolina.

In 1993 the agency redoubled its efforts to educate the public
about the perils of pot when figures showed that more young people
were taking it up after a long period when it seemed to have fallen out
of favour. In a single year from 1994 to 1995 the proportion of
teenagers smoking marijuana rose from 6 per cent to 82 per cent.
And the average age at which people first try the drug has fallen from
18.8 in 1987 to 16.3 today.

"Our teenage drug problem is for the most part a marijuana
problemand we have a generation of children who are using
marijuana earlier and earlier and are more and more likely to be armed
with the dangerous misconception that it will do them no harm," says
Donna Shalala the US Secretary of Health.

According to the NIDA a number of animal and human studies
show that smoking marijuana can have a range of ill effects including
impairment of memory brain damage lung cancer and damage to the
immune system and can lead to harder drugs.

The NIDA also disapproves of the idea of dispensing a drug in
a cigarette. The panel suggested that a smokeless inhaler that heated
the drug and vaporised its ingredients without creating smoke might
solve this problem.

Political problems aside John Morgan medical professor at the
City University of New York believes there is so much evidence that
the drug is safe that it could take as little as three months to approve
marijuana as a prescription drug. With so much existing research
showing the relative safety of pot it is time to move straight to trials of
the drug s effectiveness he says.

As far as the FDA is concerned any drug and that includes
marijuanaonly has to be shown to be safe and effective says Robert
Temple the agency s associate director for medical policy. It does not
have to be shown to be better than existing drugs. But realistically for
marijuana to make it onto the market its proponents are going to have
to show it is not only as good as existing drugs but better says Temple.
Smoked marijuana will need to show it has advantages to overcome the
opposition of the sceptics. Showing superiority is not normally a
requirement. It s hard to prove.