Pharmacogenetics of Disulfiram for Cocaine

Dopamine, a type of neurotransmitter, is the brain's "feel good" chemical. The amount of dopamine in the body may be an important factor in how cocaine addicts respond to treatment. Disulfiram, like cocaine, enhances dopamine activity. Upon taking disulfiram, subsequent intake of cocaine may elevate dopamine to excessive levels that produce extreme discomfort. DBH is an enzyme that breaks down dopamine. A particular variation in the DBH gene can affect the amount of dopamine that is released in the body. Therefore, cocaine addicts with varying DBH genes may respond differently to treatment. The purpose of this study is to compare the effectiveness of disulfiram in preventing relapse among methadone-maintained individuals addicted to both cocaine and opioids who may have different DBH genes. This 17-week study will begin with a 2-week methadone stabilization period. Participants will then be randomly assigned to receive a daily dose of either 250 mg of disulfiram or placebo for 12 weeks, while concurrently receiving methadone treatment. All participants will stop receiving study medication at Week 14, at which point they will undergo a 4-week methadone detoxification period. Participants will report cocaine and other drug use, as well as any cocaine cravings that they experience. Cocaine levels will be monitored throughout the study with urine tests. The DBH gene of each participant will be examined to determine its specific make-up and any particular variations.