Efficacy of Psychostimulant Drugs for Cocaine Dependence

Cocaine dependence is a frequent disorder for which no medication has clearly proved to be efficacious. Substitution therapy involves the replacement of abused drug, which is often illegal, used several times a day, by a legal, orally administered one. A substitutive drug has similar effects to the abused one, but with a lower addictive potential therefore leading to drug abstinence and involving patients to follow medical and psychological assistance. This strategy has proved to be efficacious for heroin and nicotine dependence. In this review we investigated if psychostimulant substitution was efficacious for cocaine dependence. We found that sixteen studies that had enrolled 1,345 patients investigated the efficacy of psychostimulants against placebo for cocaine dependence. Seven drugs with psychostimulant effect or metabolized to a psychostimulant have been investigated: bupropion, dexamphetamine, methylphenidate, modafinil, mazindol, methamphetamine and selegiline. Psychotherapy was provided in all clinical trials. Study length ranged from 6 to 24 weeks. Psychostimulants did not improve cocaine use, had an unclear beneficial effect over sustained cocaine abstinence and were not associated with higher retention in treatment. Psychostimulants did not increase risk of serious adverse events. It was found that psychostimulants could be efficacious for some groups of patients, such as methadone maintained dual heroin-cocaine addicts. Therefore, psychostimulants, though have not proved yet their efficacy for cocaine dependence, deserve further investigation.