It is estimated that more than 50 percent of individuals addicted to opiates such as heroin also are addicted to cocaine. A study in the Spring 2000 issue of Biological Psychiatry reports that combining buprenorphine, an alternative to methadone for treating opiate addiction, with disulfiram (marketed as Antabuse and used in treating alcoholism) was more effective than buprenorphine alone in reducing cocaine use in persons with this dual addiction.
"While it is known that Antabuse produces an aversion to alcohol, this study could herald an important breakthrough in treating cocaine addiction. If disulfiram reduces the pleasurable effects of cocaine, as it does those of alcohol, it could be a powerful deterrent to cocaine use and a very useful adjunct therapy," explained Dr. Alan I. Leshner, Director, National Institute on Drug Abuse (NIDA).
Previous research has shown that either buprenorphine or methadone alone is effective in reducing opiate use, but neither is effective in reducing concurrent cocaine use by opiate-dependent individuals. The study, funded by NIDA and conducted by Dr. Tony P. George and his colleagues at the Yale University School of Medicine, found that the participants who received a combination of disulfiram and buprenorphine abstained from cocaine use for longer periods of time than those who received only buprenorphine. These same participants also achieved three weeks of continuous cocaine abstinence sooner than those who received buprenorphine alone. No significant differences were found in the total weeks of opiate abstinence between the disulfiram/buprenorphine and the buprenorphine-only group. Buprenorphine is a mu opioid partial agonist that NIDA and Reckitt and Colman have co-developed for treating opiate addiction. Buprenorphine has reached the final stages of the Food and Drug Administration's approval process for new drugs.
According to Dr. George, this research reinforces previous studies that suggest administering disulfiram prior to cocaine inhalation may block the pleasurable and rewarding effects caused by an excessive release of dopamine in the brain after cocaine use. Instead of experiencing euphoria and other feelings of well being associated with cocaine use, an individual who has taken disulfiram before using cocaine will experience adverse reactions such as anxiety, dysphoria or paranoia.
In the study, 20 individuals addicted to both opiates and cocaine were placed on buprenorphine maintenance therapy. While all the participants continued to receive buprenorphine, 11 were randomly assigned to receive disulfiram and nine were assigned to placebo for 12 weeks of treatment. Of the 20 individuals enrolled, 15 participants completed the study--eight of those assigned to disulfiram and seven who had been randomized to placebo.
Larger, controlled studies of disulfiram for treating cocaine addiction are planned in buprenorphine-maintained participants.