Several million Americans abuse cocaine, and there is currently no approved drug therapy to help treat the addiction. Research has begun to focus on the development of vaccines that can treat addiction by blocking a drug's rewarding effect on the user. Ongoing trials are investigating the efficacy of vaccines designed to curb addiction to a variety of substances, including nicotine, methamphetamines, and cocaine. Recently, data has been released showing that a vaccine may help in the treatment of cocaine addiction.
Vaccine Can Assist in Cocaine Users' Rehabilitation
The cocaine vaccine (TA-CD) is designed to raise anti-cocaine antibodies in the circulation. These antibodies bind to the cocaine in the bloodstream of an addict. The bound cocaine is not able to cross the blood-brain barrier, so the user does not get a pleasurable response from the drug. If cocaine use does not result in a euphoric effect, then it becomes much easier for an addicted individual to stop taking the drug.
Cocaine Vaccine Reduces Drug Use in Recipients
A clinical trial tested the cocaine vaccine in 55 cocaine-using volunteers who were all enrolled in a methadone program for opiate abuse. Results from previous animal studies suggested that the vaccine would be most effective when anticocaine antibody levels in volunteers reached 43 micrograms per milliliter or higher. The researchers found that the volunteers with high anticocaine antibody levels had cocaine-free urine tests 45% of the time. In contrast, participants that did not achieve a high level of antibodies after vaccination (62%) and those that received placebo treatment were cocaine-free only 35% of the time.
All volunteers in the study reduced their cocaine use, but began using again when the effects of the vaccine wore off. It is likely that vaccination would be necessary every two months to keep antibody levels high enough to control the euphoric effects of cocaine.
Small studies have shown that vaccines may be able to help reduce substance abuse in addicts. It appears likely that vaccines will eventually be integrated into treatment plans for addiction, and may help more drug users recover. However, large clinical studies are still needed before the cocaine vaccine, and other vaccines can be approved by the FDA for the treatment of drug addiction. Cocaine-users that do not want to wait for the approval of the cocaine vaccine can consider enrolling in these future clinical trials.
References
Martell BA, et al "Cocaine vaccine for the treatment of cocaine dependence in methadone-maintained patients: A randomized, double-blind, placebo-controlled efficacy trial" Arch Gen Psych 2009; 66(10): 1116-23.
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