Effectiveness of Tiagabine for Cocaine Dependence in Methadone-Maintained Individuals - 1

The tiagabine group will start receiving tiagabine 4mg in the evening of the first day on week 2. The dose will be titrated every third day, until the target dose of 32mg/day is achieved by week 5. The study medication must be titrated to 32 mg/day or to the subject's maximum tolerated dose (MTD).