Double Blind Study of Vigabatrin for the Treatment of Cocaine Dependence

Inclusion criteria

In order to participate in the study, subjects must

• Be at least 18 years of age and no older than 55 years of age.
• Weigh more than 100 pounds.
• Have a DSM-IV diagnosis of cocaine dependence.
• Be seeking treatment for cocaine dependence.
• Have a urine sample positive for qualitative cocaine toxicology at initial screening.
• Have the ability to understand, and having understood, provide written informed consent to comply with the treatment protocol.
• Have a history and brief physical examination that demonstrate no clinically significant contraindication for participating in the study, in the judgment of the admitting physician and the Principal Investigator.
• Have normal, or, if necessary, corrected visual acuity, visual fields, and normal fundoscopy findings

Exclusion criteria

• In order to participate in the study, subjects must not:

• Meet DSM-IV criteria for current dependence on any psychoactive substance other than cocaine, alcohol, nicotine, or marijuana or physiological dependence on alcohol requiring medical detoxification.
• Have neurological or psychiatric disorders such as: psychosis, bipolar illness, major depression, organic brain disease, dementia, any disorder which would require ongoing treatment or which would make study agent compliance difficult, history of suicide attempts assessed and/or current suicidal ideation/plan.
• Have serious medical illnesses or other potentially life threatening or progressive medical illness other than addiction that may compromise subject safety or study conduct.
• Have a history of traumatic head injury.
• Be mandated by a court to obtain treatment for cocaine dependence.
• Have been treated for cocaine addiction, or abstained from cocaine use for a significant period, within the 6 months preceding screening.
• Be unable to complete the study protocol because of probable incarceration or relocation from the clinical area.
• Have AIDS (although AIDS is an exclusion criterion, a positive antibody titer to HIV is not).
• Have active syphilis that has not been treated or refuse treatment for syphilis
• Have a history of neuroleptic malignant syndrome.
• Have known or suspected hypersensitivity to vigabatrin or any other GABAergic drug.
• Have received a drug with known potential for toxicity to a major organ system within 30 days prior to study entry (e.g., isoniazid, methotrexate).
• Have participated in any experimental study within 4 weeks, or participated in any clinical trial utilizing vigabatrin.
• Be pregnant or lactating.
• Have any clinically significant abnormal laboratory value.
• Have had electroconvulsive therapy with the 3 months preceding screening.
• Have had any opiate-substitutes (methadone, LAAM, buprenorphine) within 2 months preceding screening.
• Have a history of i.v. cocaine (or other psychoactive drug) use within 2 months preceding screening.
• Have a current or past history of seizure disorder, including alcohol- or stimulant related seizure, febrile seizure, or significant family history of idiopathic seizure disorder.
• Have a visual field defect, or factor predisposing to visual field defects, including glaucoma, severe myopia, retinal disorder, cataracts, diabetes or uncontrolled hypertension.
• Have my illness, condition, and use of medications, in the opinion of the Principal Investigator and the admitting physician, which would preclude safe or successful completion of the study.
• Be using vigabatrin or any medication that could interact adversely with vigabatrin administration, based on the longest time interval of A or B below:

• A) Five half-lives of other medication or active metabolite(s), whichever is longer;
• B) Two weeks.
• Be lactose intolerant.