Eric Clapton once sang “she don’t lie, cocaine,” but a new agent may keep the drug from ever saying anything at all.
Researchers announced on Tuesday that a new vaccine can help reduce cocaine abuse among 2.5 million Americans dependent on the drug.
In a study published in the October issue of the journal Archives of General Psychiatry, Baylor College of Medicine psychiatrist Thomas Kosten and a team of researchers administered a vaccine to 115 drug abusers in Houston.
Over 12 weeks, nearly all participants got five shots of cocaine vaccine or a dummy substance. They were followed for an additional 12 weeks. All participants also attended weekly relapse-prevention therapy sessions, had their blood tested for antibodies and their urine tested for cocaine and heroin.
The result? Thirty-eight percent of the cocaine abusers produced anti-cocaine antibodies. With that kind of biological support, those patients were found to be 45 percent likely to have a cocaine-free urine test after seven weeks.
In contrast, 35 percent of those who received a placebo vaccine had a cocaine-free urine test.
Though there’s no virus involved, the “vaccine” is called as such because it trains the human body to view cocaine as a hostile presence. Inside the syringe, a cocaine-like substance named succinylnorcocaine encourages the body to produce antibodies hostile to cocaine.
Those antibodies bind to the cocaine, preventing it from absorbing into the brain and blocking it from affecting dopamine levels, and thus the drug high.
The team worked with cocaine abusers also addicted to heroin who sought methadone treatment at a New Haven, Conn. clinic. Though methadone treats heroin addiction and not cocaine, it requires repeat clinic visits, making it easier for the researchers to work with the participants over a 12 week period.
So far, the development has seen limited success: just 38 percent of the subjects who got the vaccine produced significant levels of antibodies.
A larger study in six cities is planned for January 2010. If successful, the vaccine could become available in two to three years.
Currently, no FDA-approved treatment exists for cocaine addiction.
The study was funded by the National Institute on Drug Abuse.
