Antipsychotic medications for cocaine dependence

Amato L, Minozzi S, Pani PP, Davoli M

Summary

Antipsychotic medications for cocaine dependence

Cocaine dependence is often associated with medical, psychological and social problems for the individual and public health problems for the community. Users have a role in the spread of the infectious diseases AIDS, hepatitis and tuberculosis as well as crime, violence and neonatal drug exposure. Medication with antidepressants, anticonvulsants such as carbamazepine, and dopamine agonists to assist in stopping cocaine use is not supported by evidence from Cochrane reviews. Use of antipsychotic agents has also been considered, particularly because cocaine can induce hallucinations and paranoia that mimic psychosis.
When all trial results comparing any antipsychotic drug to placebo were grouped together, antipsychotic drugs did not have any benefit in reducing dependency on cocaine. The review authors identified seven controlled trials involving a total of 293 adults, mean age 40 years. The studies were conducted in USA in both inpatient and outpatient settings and had a duration of 5 to 168 days (mean 61 days). Six trials randomised participants to receive an antipsychotic drug or placebo; the seventh compared olanzapine to haloperidol. The antipsychotic medications used were risperidone (three studies, 1 to 4 mg/day); olanzapine (three studies, 10 mg/day); and haloperidol (two studies, 4 and 10 mg/day). Risperidone treatment reduced the number of people who dropped out from treatment (three studies, 144 participants; relative risk 0.77, range 0.77 to 0.98); in individual studies olanzapine and haloperidol showed better results than placebo but the results come from studies to small to give them conclusive (34 participants) and (31participants) respectively. Information on acceptability of treatment in terms of side effects, abstinence from cocaine use and withdrawal symptoms was limited.The methodological quality of the small number of identified trials was good but the number of participants was small and a variety of ways of reporting results were used.