ANTI-OBESITY PILL MIGHT FIGHT DRUG ABUSE

NEW YORK - A pill that helps you lose weight and quit smoking? That
was amazing enough to capture headlines last week. But scientists say
the experimental drug might be even more versatile, providing a new
tool to help people stop abusing drugs and alcohol, too.

It's called rimonabant, or Acomplia, and last week researchers
reported it could help people not only lose weight but keep it off for
two years. That burnished the drug's reputation after two studies in
March, which suggested it could fight both obesity and smoking, two of
humanity's biggest killers.

The French pharmaceutical firm Sanofi-Aventis plans to seek federal
approval for rimonabant next year.

But the drug's benefits may go beyond just smokers and obese people,
researchers say.

"I think it's going to have a big impact on the treatment of
addiction," said Dr. Charles O'Brien, an addiction expert at the
University of Pennsylvania and the Philadelphia Veterans Affairs
Medical Center.

Animal studies suggest rimonabant can block the effects of marijuana
and fight relapse in alcohol and cocaine abuse, he said. Once it is
approved for treating obesity or smoking, "we'll be free to study it
in these other areas and I'll try to get my hands on it as quickly as
possible," O'Brien said.

He's not alone in his enthusiasm.

The National Institute on Alcohol Abuse and Alcoholism is interested
in seeing whether rimonabant can help treat heavy drinkers, said Dr.
George Kunos of the institute. No human test results for rimonabant in
alcohol abuse have yet been published, he said.

But researchers at the National Institute on Drug Abuse reported in
2001 that a single dose of the drug could block the effects of smoked
marijuana in people, not just animals. That suggests the drug could be
useful in treating marijuana dependence, said Marilyn Huestis,
principal investigator of the study. The institute is now pursuing
follow-up research, said Huestis, acting chief for chemistry and drug
metabolism research at NIDA.

Rimonabant's versatility traces back to its effects on the brain's
reward system, circuitry that tells you to keep on doing something.
Basically, it appears to help break the connection between an activity
like smoking and the rewarding feeling it causes in the brain.

The body has its own marijuana-like substances called
endocannabinoids, and they activate certain brain cells that in turn
can lead to stimulation of the brain's reward system. Pleasurable
things like drinking alcohol are thought to activate a feeling of
reward by acting through the endocannabinoid system.

"We think that the (endocannabinoid) system is overactivated by
chronic smoking, or perhaps even excessive overeating," said Dr.
Robert Anthenelli of the University of Cincinnati College of Medicine
and the Cincinnati Veterans Affairs Medical Center. He's on the
advisory board of Sanofi-Aventis.

Rimonabant blocks the effect of the natural endocannabinoids by
keeping them from latching onto the brain cells they normally
stimulate, he said. In smokers, for example, that seems to restore the
natural balance of the brain reward circuitry, he said.