Anticonvulsants for cocaine dependence
Abstract
Background
Cocaine dependence is a major public health problem that is characterized by recidivism and a host of medical and psychosocial complications. Although effective pharmacotherapy is available for alcohol and heroin dependence none exists currently for cocaine dependence despite two decades of clinical trials primarily involving antidepressant, anti convulsivant and dopaminergic medications. There has been extensive consideration of optimal pharmacological approaches to the treatment of cocaine dependence with consideration of both dopamine antagonists and agonists. Anticonvulsants have been candidates for the treatment of addiction based on the hypothesis that seizure kindling‐like mechanisms contribute to addiction.
Objectives
To evaluate the efficacy and the acceptability of anticonvulsants for cocaine dependence
Search methods
We searched the Cochrane Drugs and Alcohol Groups specialised register (issue 4, 2007), MEDLINE (1966 ‐ march 2007), EMBASE (1988 ‐ march 2007), CINAHL (1982‐ to march 2007)
Selection criteria
All randomised controlled trials and controlled clinical trials which focus on the use of anticonvulsants medication for cocaine dependence
Data collection and analysis
Two authors independently evaluated the papers, extracted data, rated methodological quality
Main results
Fifteen studies (1066 participants) met the inclusion criteria for this review: the anticonvulsants drugs studied were carbamazepine, gabapentin, lamotrigine, phenytoin, tiagabine, topiramate, valproate. No significant differences were found for any of the efficacy measures comparing any anticonvulsants with placebo. Placebo was found to be superior to gabapentin in diminishing the number of dropouts, two studies, 81 participants, Relative Risk (RR) 3.56 (95% CI 1.07 to 11.82) and superior to phenythoin for side effects, two studies, 56 participants RR 2.12 (95% CI 1.08 to 4.17). All the other single comparisons are not statistically significant.
Authors' conclusions
Although caution is needed when assessing results from a limited number of small clinical trials at present there is no current evidence supporting the clinical use of anticonvulsants medications in the treatment of cocaine dependence. Aiming to answer the urgent demand of clinicians, patients, families, and the community as a whole for an adequate treatment for cocaine dependence, we need to improve the primary research in the field of addictions in order to make the best possible use out of a single study and to investigate the efficacy of other pharmacological agent.
PICOs
Plain language summary
Anticonvulsants for cocaine dependence.
Cocaine is an illicit drug used as a powder for intranasal or intravenous use or smoked as crack. Short and long‐term use of this drug spreads infectious diseases (for example AIDS, hepatitis and tuberculosis), crime, violence and prenatal drug exposure. Cocaine dependence has medical and psychosocial complications and is a major public health problem. No proven pharmacological treatment exists for cocaine dependence. Antidepressant, anticonvulsants and dopaminergic medications have all been trialled. The present review looked at the efficacy and safety of anticonvulsant drugs for treating cocaine dependence, as a class and individually. The review authors identified 17 randomised controlled trials involving 1194 participants, 80% male, with a mean age of 36 years. The mean duration of the trials was 11 weeks (range 1 to 24 weeks). All the trials were conducted in USA, 16 as outpatients. Very limited evidence can be drawn from the included trials. No significant differences were found between a placebo and any anticonvulsant in reducing the number of dropouts from treatment, use of cocaine, craving, and severity of dependence, depression or anxiety. Placebo was superior to gabapentin in reducing the number of dropouts from treatment (two studies) and use of cocaine. Gabapentin (one study, 95 participants) and phenytoin (two studies, 56 participants) had a greater number of side effects than the placebo. Although the methodological quality of the included studies was good, the sample sizes were small. Most anticonvulsants were used in single studies. Health effects of various substances of abuse seem to be strongly dependent on social context and the location of the studies could affect the treatment effect. Different rating systems were used and symptoms were not categorised as mild, moderate or severe to allow comparison of results between studies.
