SYNTHETIC MARIJUANA COMPOUND SHOWS PROMISE

Marijuana can ease pain even for longtime sufferers of disease, but
the illegal herb's mind-altering properties make it less than ideal as
a medication.

German researchers now have found that a synthetic version of one of
many marijuana compounds safely reduced chronic nerve pain without
impairing thinking and behavior. If the preliminary findings hold up
in larger trials, capsules containing this compound might one day be
prescribed for hard-to-treat pain.

The principal active ingredient in cannabis is tetrahydrocannabinol,
or THC. That compound has been the most studied, but researchers
around the world are also looking more closely at the plant's other
chemical compounds for potential health benefits. Scores of them
belong to a group called cannabinoids; others include flavonoids,
which are thought to have antioxidant properties.

"It's not a surprise that these cannabinoids have medical benefit,"
said Dr. Donald I. Abrams, an AIDS specialist conducting clinical
trials of marijuana at San Francisco General Hospital.

People with cancer, AIDS and other chronic diseases have long attested
to the plant's ability to provide relief from nausea and pain. "That's
why we're investigating marijuana," Abrams said.

Previous studies have shown some cannabinoids have limited ability to
blunt acute nerve pain, typically associated with an injury. But the
German study found that a cannabinoid called CT-3 could help sufferers
of chronic neuropathy, who often don't respond to standard
medications.

CT-3 is related to THC. But the problem with THC is that even at low
doses, it can impair thinking and coordination, and create anxiety,
panic attacks, psychosis and paranoia, as well as dry mouth, blurred
vision, and a drop in blood pressure upon standing.

Despite these effects, scientists have remained interested in
cannabinoids, because the body has natural cannabinoid receptors that
offer potential drug targets.

CT-3 first showed promise in animals as an anti-inflammatory and as a
reliever of two aspects of neuropathy: pain and extreme sensitivity to
ordinary sensations.

Researchers at Hannover Medical School in Germany, working with an
American colleague, gave various doses of CT-3 to 24 volunteer
patients with chronic neuropathic pain in places such as the foot,
arm, face and head. Many patients also were taking other
pain-relieving medications such as narcotics, muscle relaxants,
antidepressants and sedatives.

The researchers found that CT-3 was more effective than a placebo at
relieving pain; its effects were greatest with milder pain. Increasing
the dose brought no greater relief. The major side effects were dry
mouth and fatigue.

"What's promising is that there can be a product that stimulates the
cannabinoid receptors and does not have the emotional and
hallucinatory effects otherwise known for THC," said Dr. Joel Saper, a
neurologist who directs the Michigan Head-Pain and Neurological
Institute in Ann Arbor. He'd like to see longer CT-3 studies using
larger numbers of patients who aren't taking other pain medications:
"We need to see how this would work in patients not on all these drugs."