Clinical efficacy of gabapentin versus tiagabine for reducing cocaine use among cocaine dependent methadone-treated patients

Drug Alcohol Depend. 2007 Feb 23;87(1):1-9. doi: 10.1016/j.drugalcdep.2006.07.003. Epub 2006 Aug 22.


Background: GABAergic medications appear to reduce the reinforcing effects of cocaine by attenuating cocaine-induced dopamine release. This study evaluated gabapentin and tiagabine compared to placebo in reducing cocaine taking behavior.

Methods: A total of 76 treatment seeking, cocaine dependent, methadone-treated, predominately Caucasian male subjects were randomly assigned to tiagabine 24 mg/day (N=25), gabapentin 2400 mg/day (N=26) or placebo (N=25) in a 10-week double-blind placebo-controlled trial. Study medications were slowly increased to their full dosages by the end of week 5 and maintained through week 10. The primary outcome measure was thrice-weekly drug free urine samples.

Results: Treatment retention was significantly less for the gabapentin group relative to the other groups (log rank=5.29, d.f.=1, p=0.02). The proportion of cocaine-free urine samples during weeks 6-10 was significantly larger in the tiagabine treated group (p<0.05). The longitudinal data showed significant change in thrice-weekly cocaine free urines that reached a greater abstinent rate for the tiagabine treated group (22%) compared to gabapentin (5%) or placebo (13%) treated groups. Mixed-effects ordinal regression models showed a significant tiagabine by time interaction compared to gabapentin (Z=2.48, d.f.=1, p=0.01) and placebo (Z=3.90, d.f.=1, p=0.0001). The gabapentin group did not differ from placebo.

Conclusion: Gabapentin showed poor treatment retention and ineffectiveness in reducing cocaine use. Tiagabine significantly reduced cocaine taking behavior compared to placebo or gabapentin among methadone-stabilized cocaine abusers.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Amines / administration & dosage
  • Amines / therapeutic use*
  • Anti-Anxiety Agents / administration & dosage
  • Anti-Anxiety Agents / therapeutic use*
  • Cocaine-Related Disorders / epidemiology
  • Cocaine-Related Disorders / rehabilitation*
  • Cocaine-Related Disorders / urine
  • Cognitive Behavioral Therapy / methods
  • Combined Modality Therapy
  • Cyclohexanecarboxylic Acids / administration & dosage
  • Cyclohexanecarboxylic Acids / therapeutic use*
  • Double-Blind Method
  • Drug Administration Schedule
  • Female
  • GABA Agonists / administration & dosage
  • GABA Agonists / therapeutic use*
  • Gabapentin
  • Humans
  • Male
  • Methadone / administration & dosage
  • Methadone / therapeutic use*
  • Narcotics / administration & dosage
  • Narcotics / therapeutic use*
  • Nipecotic Acids / administration & dosage
  • Nipecotic Acids / therapeutic use*
  • Tiagabine
  • Treatment Outcome
  • gamma-Aminobutyric Acid / administration & dosage
  • gamma-Aminobutyric Acid / therapeutic use*


  • Amines
  • Anti-Anxiety Agents
  • Cyclohexanecarboxylic Acids
  • GABA Agonists
  • Narcotics
  • Nipecotic Acids
  • gamma-Aminobutyric Acid
  • Gabapentin
  • Methadone
  • Tiagabine