Tiagabine increases cocaine-free urines in cocaine-dependent methadone-treated patients: results of a randomized pilot study

Authors


Gerardo Gonzalez MD,
VA Connecticut Healthcare System
Department of Psychiatry 116A4
950 Campbell Avenue, Bldg 36
West Haven, CT 06516
USA
Tel. (203) 932 5711 ext 5453
Fax: (203) 937 3478
E-mail: Gerardo.Gonzalez-Haddad@yale.edu

ABSTRACT

Aims  We sought to evaluate the safety and efficacy of the GABAergic agent tiagabine in reducing cocaine use among methadone-treated patients.

Design  Ten-week randomized double-blind placebo-controlled trial.

Setting  Opiate Treatment Research Program, Veteran's Affairs Connecticut Healthcare System in West Haven, Connecticut, USA.

Participants  The participants were 45 cocaine-dependent methadone-treated patients who were predominately Caucasian (75.6%), male (77.8%) and never married (53%) with an average age of 38 years (SD = 6.5).

Interventions  Comparison groups received tiagabine 12 mg/day (n = 15), tiagabine 24 mg/day (n = 15) or placebo (n = 15).

Measures  Baseline assessments included the Structured Clinical Interview for DSM-IV, the Addiction Severity Index, a urine drug test, self-reported use and opiate withdrawal scales. Urine drug tests were performed thrice weekly.

Findings  Treatment retention was over 80% for all treatment groups. The sample mean (± SE) of cocaine-free urines for the first week after study entry and before tiagabine was started was 1.16 (0.19) urines/week. During weeks 9 and 10 cocaine-free urines increased significantly from baseline by 33% with high-dose tiagabine (24 mg/day), by 14% with low-dose tiagabine (12 mg/day) and decreased by 10% with placebo (hierarchical linear model, Z= 2.03; P < 0.05). Self-reported cocaine use also decreased significantly more with active medications than with placebo.

Conclusions  Tiagabine at 24 mg/day was well tolerated among these methadone-treated patients with only one reporting headache. Tiagabine appears to be a promising GABAergic medication that moderately improves cocaine-free urines.

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