From Medical Correspondent Dr. Steve Salvatore

NEW YORK (CNN) -- A drug used to treat epilepsy may stop the addictive effect of nicotine, researchers report.

Scientists from the Brookhaven National Laboratories in New York say Vigabatrin or GVG, a drug available in Europe and Canada, can quell nicotine cravings in animals.

"We demonstrated that GVG completely abolished nicotine-induced seeking behavior as well as the ability to acquire this behavior," said researcher Dr. Steven Dewey.

When a person smokes a cigarette, nicotine causes the brain to release the chemical dopamine. It stimulates the pleasure centers of the brain, encouraging the smoker to smoke again.

GVG blocks the effect of nicotine on dopamine.

Each year, 35 million smokers try to kick the habit, but only 7 percent succeed for more than a year.

Researchers say it doesn't take much GVG to kick nicotine cravings. Just one-tenth to one-twentieth the dose used to treat epilepsy.

That's good news, because at higher doses, there are some side effects.

"There seems to be a loss of visual acuity in those areas of the visual field right next to the nose, and it is not yet known at this time if they are reversible," said Dr. Jonathan Brodie, a psychiatry professor at New York University.

In August, it was reported that GVG blocked the additive effect of cocaine in animals.

New preliminary studies show it may work for other addictive substances.

"GVG is effective at blocking the biochemically induced changes in the brain associated with alcohol, methamphetamines, amphetamine and morphine," Dewey said.

The researchers warn, however, the drug is still in the early phase of research and more testing is needed.

"We neither suggest, nor do we believe, that even under the best circumstances, GVG will ever be a magic bullet," Dewey said.

Experts say they expect GVG and similar drugs to work hand-in-hand with traditional therapy like counseling and support groups.