Subjects: R and D
Scientists have made some progress in their effort to develop a vaccine for cocaine addiction. The vaccine is actually a series of injections that trigger an immune response to cocaine. The newly-created antibodies prevent the drug from entering the brain and thus blunt its euphoric effects.
To assess the safety and efficacy of their coke vaccine, Thomas Kosten and colleagues at Baylor randomized 115 cocaine addicts to receive either 5 shots of the vaccine over a 12 week period or a series of similarly timed placebo injections.
They monitored cocaine intake using urinalyses.
Most subjects smoked crack cocaine. Many also used marijuana (18%), alcohol (10%), and narcotics (44%).
Among subjects who received all 5 shots, 38% achieved sufficient antibody levels to blunt the effects of the drug. Antibodies remained in the bloodstream for 8-10 weeks after the final stick.
In this subset, 53% of the subjects stopped using cocaine—significantly more than the 23% of subjects who did not produce enough antibodies.
The vaccine was well tolerated, with no treatment-related serious adverse events or deaths.
But the partial success was associated with some risk. Some subjects began snorting massive amounts of the drug in an effort to overcome the vaccine’s effects. Some amassed 10 times the amount in their systems than had been encountered before the trial began.
“After the vaccine, doing cocaine was a very disappointing experience for them,” Kosten told the Washington Post. “Previous research has shown that a reduction in use is associated with a significant improvement in cocaine abusers’ social functioning and thus is therapeutically meaningful.”
Kosten plans to begin a larger vaccine trial this spring.
About 2.1 million Americans have used cocaine in the last month, studies show.
The write-up appears in the Archives of General Psychiatry.