A Phase II, Double-Blind, Placebo-controlled, Pilot Trial of Acamprosate for the Treatment of Cocaine Dependence

The primary objective of the trial is to evaluate the safety, tolerability and efficacy of acamprosate for the treatment of 60 treatment seeking cocaine dependent outpatients. The study will be an exploratory, double-blind, placebo-controlled 9-week trial, with a 2-cell design (30 subjects per cell) in which either 1998 mg/day of acamprosate (666 mg TID) or placebo will be given. Study medications will be given by medical practitioners, trained to provide NIAAA's COMBINE Medical Management. In addition, patients will receive weekly individual psychosocial treatment sessions utilizing Cognitive Behavioral Therapy (CBT) at the University of Pennsylvania Treatment Research Center (TRC).

Primary Hypotheses:

1. Efficacy: Acamprosate-treated subjects will demonstrate less cocaine use during the medication/placebo treatment phase, compared to placebo-treated subjects. Cocaine use will be measured by self-report from the TLFB confirmed with urine assay for benzoylecgonine (BE)
2. Safety and Tolerability: Acamprosate-treated subjects and placebo-treated subjects will report similar rates of adverse events, assessed by weekly evaluations, physical exams and laboratory testing.

Secondary Hypotheses:

1. Acamprosate-treated subjects, compared to placebo-treated subjects, will report less craving for cocaine, measured by lower scores on the Brief Substance Craving Scale (BSCS) (Somoza et al, 1995) and Multiple Choice Procedure (MCP) (Griffiths et al., 1993) during the medication treatment phase.
2. Acamprosate-treated subjects, compared to placebo-treated subjects, will report fewer withdrawal symptoms, measured by the Cocaine Selective Severity Assessment (Kampman et al., 1998).
3. Acamprosate-treated subjects, compared to placebo-treated subjects, will report fewer mood and anxiety symptoms, measured by the Hamilton Depression Rating Scale (HAM-D) (Hamilton, 1967), Hamilton Anxiety Rating Scale (HAM-A) (Hamilton, 1969), and Clinical Global Impression Scale (CGI).
4. Subjects who are highly acamprosate-adherent (>80% pills taken, verified by combining patient report with blister cards) will have more cocaine non-use days during the medication treatment phase, compared to those who are less acamprosate-adherent (<80% pills taken).