The epilepsy drug vigabatrin appears to be safe for the treatment of cocaine or methamphetamine dependence, new study results suggest.

Dr. Stephen L. Dewey, a neuroanatomist at Brookhaven National Laboratory in Upton, New York, and colleagues report their findings in the medical journal Synapse.

Dewey’s team previously reported that vigabatrin is effective in the treatment of cocaine dependence. However, vigabatrin treatment has been associated with vision problems.

They therefore investigated the safety and effectiveness of low dose vigabatrin in ten patients addicted to methamphetamines, three with cocaine dependence, and 17 addicted to both drugs. On average, the 30 subjects had been addicted for 13 years.

Sixteen of the 18 participants who completed the 9-week study remained drug-free during the last 6 weeks of the trial, according to urine test results.

“It is remarkable that half of these predominantly methamphetamine-dependent individuals remained essentially drug free for approximately 6 consecutive weeks despite living in their normal home environment with ready access to drugs,” the authors write.

Eye exams conducted at the end of treatment and at 1 to 2 months following the end of treatment showed no evidence of visions problems. Furthermore, there were no changes in vital signs, even among those who continued abusing drugs.

The strategy of using vigabatrin is particularly exciting, Dewey told Reuters Health, because it can potentially be applied to any chemical addiction, from nicotine to alcohol to heroin.

“The beauty of it is that you’re not only blocking the effect of the drug, but you’re also blocking the biochemical effect of environmental cues…the number-one cause of relapses,” he added.

But he also cautions that vigabatrin “is not a magic bullet.” Support groups remain critical in successfully treating chemical addictions, he said.

SOURCE: Synapse, February 2005.