Vigabatrin for Cocaine and Alcohol Dependence

Inclusion Criteria:

1. Male and females, 18 years of age or older.

2. Meets DSM-IV criteria for current diagnoses of cocaine and alcohol dependence,
determined by the SCID-IV.

3. Used cocaine in the past 30 days and used no less than $200 of cocaine in a
consecutive 30 day period over the 90 day period prior to intake. Meets the following
drinking criteria as measured by the Timeline Followback (TLFB) (Sobell 1995) a drank
within 30 days of intake day, b. reports a minimum of 48 standard alcoholic (avg. 12
drinks/wk) in a consecutive 30-day period over the 90-day period prior to starting
intake (i.e., a minimum of 40% days drinking), and c. has 2 or more days of heavy
drinking (defined as greater than 4 drinks per day in males and greater than 3 drinks
per day in females) in this same pre-treatment period.

4. Three consecutive days of abstinence from alcohol directly prior to the day of
randomization, determined by self-reports and confirmed by negative breathalyzer
tests, and a Clinical Institute Withdrawal Scale for Alcohol (CIWA-AR) (Sullivan and
Sellers 1989) score below eight. Subjects will be given 2 additional weeks beyond the
screening week to attain the appropriate period of alcohol abstinence prior to
randomization.

5. Have a verifiable address of principal residence, lives a commutable distance from
the TRC and agrees to attend all research visits including follow-up visits.

6. Speaks, understands, and prints in English

7. Ability to give informed consent

Exclusion Criteria:

1. Meets DSM IV criteria for dependence on any substance other than cocaine and alcohol
(except nicotine and cannabis), determined by the SCID. Needs treatment with any
psychoactive medications including any anti-seizure medications (with the exception
of diphenhydramine used sparingly, if necessary, for sleep).

2. Meets current or lifetime DSM-IV criteria for schizophrenia or any psychotic disorder
or organic mental disorder. Subject meets current DSM-IV diagnosis of any other
clinically significant psychiatric disorder that will interfere with study
participation as determined by the principal investigator.

3. Has evidence of a history of significant hematological, pulmonary, endocrine,
cardiovascular, renal or gastrointestinal disease.

4. Severe physical or medical illnesses such as AIDS, active hepatitis, significant
hepatocellular injury as evidenced by elevated total bilirubin levels (>1.3 mg/dl),
or elevated levels (over 4.5x normal) of aspartate aminotransferase (AST), and/or
alanine aminotransferase (ALT). Patients with Gilberts Syndrome will not be excluded.

5. Use of an investigational medication in the 30 days prior to randomization.

6. History of prior treatment with vigabatrin

7. History of prior treatment with drugs with known retinotoxicity

8. History of visual field defects or predisposing factors, including glaucoma, severe
myopia, retinal disorders, cataracts, diabetes, or uncontrolled hypertension.

9. Is female and tests positive on a pregnancy test, is contemplating pregnancy in the
next 6 months, is nursing, or is not using an effective contraceptive method (if
relevant). Acceptable methods of contraception include barrier methods (diaphragm or
condom with spermicide, female condom), intrauterine progesterone contraceptive
system, levonorgrestrel implant, and medroxyprogesterone acetate contraceptive
injection, copper IUD, vaginal contraceptive film, cervical cap, contraceptive foam,
hormonal vaginal contraceptive ring (NuvaRing®) or oral contraceptives.