Cocaine Vaccine May Help Addicts Avoid Relapse, Study Shows
Not all of the patients responded to the vaccine at the same rate. Urine tests showed about 45 percent of those who had the strongest response to the vaccine were entirely free of cocaine, compared with 35 percent of those who got placebo injections or who didnt form as many antibodies, according to the study published in the Archives of General Psychiatry.
One in three emergency department visits for drug- related illness is due to cocaine dependence, the article said. There isnt any drug approved for cocaine addiction by the U.S. Food and Drug Administration, according to the National Institute on Drug Abuse. Most treatment focuses on changing addicts behavior.
“When we started research on this in the 90s, everyone said we were stupid,” said study author Thomas Kosten, a professor of psychiatry, pharmacology and neuroscience at Baylor College of Medicine in Houston. “Well, its the most promising therapy for cocaine we have right now.”
“If a real vaccine-maker wanted to do this, it could be on the market in two years,” he said.
Tests in 1950s
Kosten and his colleagues started working with a potential cocaine vaccine in the mid-1990s, he said. The research developed from tests in the 1950s that found people make antibodies to small molecules, which the immune system would ordinarily ignore, if the molecules were attached to proteins — in this case, attached to cholera vaccine.
Antibodies are part of the bodys defense mechanism and are used by the immune system to identify substances that dont belong to the body. A lot of antibodies specific to cocaine would help neutralize that drug in the bloodstream, according to Kosten.
This trial lasted 12 weeks. Kosten and others from Baylor and Yale University School of Medicine injected patients five times with either a placebo vaccine or a cholera vaccine with cocaine hooked on to it, to provoke an immune response. About 38 percent of those who got vaccinated had high levels of antibodies to cocaine in their blood.
“Its exceeded our expectations,” Kosten said. “Its pretty good for keeping people from relapsing.”
With another vaccine to attach the cocaine to, it might work for a majority of people, Kosten said. Probably patients would need booster vaccinations in order to keep the antibodies at high levels, according to the paper.
A bigger study will start in January, Kosten said.