Safety and Efficacy Study of Vigabatrin to Treat Methamphetamine Dependence
Condition: Methamphetamine Dependence
Intervention: CPP-109 vigabatrin; Matching Placebo
Intervention description: tablets, bid for 12 weeks; tablets, bid, 12 weeks
Intervention MeSH terms: Vigabatrin
Phase: Phase 2
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Enrollment: 55.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No
Keywords: Methamphetamine; Dependency; Addiction; vigabatrin

Summary:

      The objective of this study is to demonstrate that a larger proportion of vigabatrin-treated
      subjects than placebo-treated subjects will be methamphetamine-free in the last 2 weeks of
      the study's Treatment Phase (Weeks 11 and 12).
    

Eligibility criteria:

        Inclusion Criteria:

        Able to understand the study and provide written informed consent.

          -  Male or female at least 18 years of age.

          -  Meets DSM-IV (Diagnostic and Statistical Manual of Mental Disorders Fourth Edition)
             criteria for methamphetamine dependence as major diagnosis, as determined by the
             Substance Abuse module of SCID (Structured Clinical Interview for DSM-IV).

          -  Provides at least one urine specimen which is positive for methamphetamine according
             to a rapid screening test.

          -  Seeking treatment for methamphetamine dependence.

          -  Have normal visual fields.

          -  Be in generally good health based on history, physical examination and laboratory
             findings.

          -  If female of childbearing potential, use acceptable contraceptive methods

        Exclusion Criteria:

          -  Has current dependence on any psychoactive substance other than methamphetamine,
             alcohol, nicotine, or cannabinoid or physiologic dependence on alcohol requiring
             medical detoxification.

          -  Has any serious medical or psychiatric illness and/or clinically significant abnormal
             laboratory values.

          -  Has history of serious cardiovascular reaction to methamphetamine.

          -  Has clinically significant cardiovascular impairment, abnormal ECG or uncontrolled
             hypertension.

          -  Be under court or other governmental agency (e.g. social services) mandate to obtain
             treatment or requiring outside urine monitoring.

          -  Be enrolled in an opiate substitution treatment program within 2 months of
             randomization.

          -  Has ever taken vigabatrin in the past.

          -  Is pregnant or lactating.

          -  Has clinically significant ophthalmologic disease, which would preclude safety
             monitoring, is undergoing treatment for ocular disease or intends to have any ocular
             surgery or procedure performed during the time of their participation in the trial.

          -  Has received a drug with known major organ toxicity, including retinotoxicity.

          -  Is currently participating in, or has been enrolled in another clinical trial within
             the last 30 days.

          -  Be anyone who, in the judgment of the investigator, would not be expected to attend
             regular study visits or to complete the study protocol.