- Two consecutive days of abstinence from cocaine and alcohol, determined by self-reports and confirmed by negative urine toxicology screens, a negative breathalyzer tests, and collateral report, a Clinical Institute Withdrawal Scale for Alcohol (CIWA-AR) (Sullivan et al., 1989) score below eight,. Subjects will be encouraged to achieve 3 consecutive days of abstinence, however, subjects who have achieved 2 consecutive days of abstinence will be included with the approval of the principal investigator. We anticipate that these subjects will comprise less than 5% of total enrolled subjects. Subjects will be given 2 additional weeks beyond the screening week to attain the appropriate period of cocaine and alcohol abstinence prior to randomization.