Carbamazepine for cocaine dependence

Abstract

BACKGROUND: Cocaine dependence has become a public health problem, developing a significant number of medical, psychological and social problems. Although there is no consensus regarding how to treat cocaine dependence, effective pharmacotherapy has a potentially major role to play as part of a broader treatment milieu. The anti-convulsant carbamazepine, a tricyclic medication that is widely used to treat a variety of neurological and psychiatric disorders, has been used for treatment of cocaine dependence, although its effectiveness has not been established. OBJECTIVES: To determine whether carbamazepine is effective for the treatment of cocaine dependence. SEARCH STRATEGY: We searched: Cochrane Controlled Trials Register (Cochrane Library issue 1, 1999), MEDLINE (f1966 - October 1997), EMBASE (1980 - October 1997), PsycLIT (1974 - July 1997), Biological Abstracts and LILACS (1982 - 1997); scan of reference list of relevant articles; personal communication; conference abstracts; unpublished trials from pharmaceutical industry; book chapters on treatment of cocaine dependence. The specialised register of trials of Cochrane Group on Drugs and Alcohol until February 2003. SELECTION CRITERIA: All randomised controlled trials focused on the use of carbamazepine versus placebo on the treatment of cocaine dependence. Trials including patients with additional diagnosis such as opiate dependence were also eligible. DATA COLLECTION AND ANALYSIS: The reviewers extracted the data independently, Odds Ratios, weighted mean difference and number needed to treat were estimated. Qualitative assessments of the methodology of eligible studies were carried out using validated checklists. The reviewers assumed that people who died or dropped out had no improvement and tested the sensitivity of the final results to this assumption. Where possible analysis was carried out according to the "intention to treat" principles. MAIN RESULTS: 5 studies were included (455 participants). No differences regarding positive urine sample for cocaine metabolites. Scores on Spielberg State Anxiety Inventory slightly favoured carbamazepine, but not statistical significance. Dropouts were high in both groups, less dropout occurred in the carbamazepine group (RR 0.87 95%CI 0.71-1.06). When no retention in treatment was due to side effects no differences were found. The number of participants presenting at least one side effect, was higher in the carbamazepine group (RR 4.33 95% CI 1.45-12.91). AUTHORS' CONCLUSIONS: There is no current evidence supporting the clinical use of Carbamazepine in the treatment of cocaine dependence. Larger randomised investigation must be considered taking into account that these time-consuming efforts should be reserved for medications showing more relevant and promising evidence.