Effects of Vigabatrin on Cocaine Self-Administration
- Registration Number
- NCT00373581
- Lead Sponsor
- New York State Psychiatric Institute
- Brief Summary
The objective of this study is to determine if vigabatrin will decrease cocaine self-administration, cardiovascular effects, subjective effects and craving compared to placebo.
- Detailed Description
Two recent open label clinical trials have reported that the anticonvulsant, gamma vinyl-GABA (GVG; vigabatrin), decreases relapse to cocaine use (Brodie et al., 2003, 2005). Vigabatrin increases neural GABA levels by irreversibly inhibiting the primary GABA degradation enzyme, GABA-transaminase; the hypothesized mechanism by which vigabatrin decreases cocaine relapse is by increasing GABA levels, thereby decreasing the effects of cocaine and cocaine-associated environmental cues on extracellular dopamine concentrations in the mesolimbic dopaminergic pathway (Morgan and Dewey, 1998). We are proposing to use our model of repeated dose cocaine self-administration to assess the interaction between vigabatrin and smoked cocaine under controlled laboratory conditions. This 57-day outpatient/inpatient /outpatient/inpatient protocol will evaluate the effects of vigabatrin maintenance (0, 3 g/day) on cocaine craving, subjective effects, and self-administration using a within-subjects design. Non-treatment seeking cocaine-dependent volunteers will be maintained outpatient for 14 days of vigabatrin maintenance prior to beginning each inpatient study phase. During the inpatient phases, volunteers will live on a hospital clinical research unit and will participate in laboratory sessions in which they will have the opportunity to purchase doses of smoked cocaine (0, 12, 25, 50 mg; $5/administration). In addition to measuring cocaine self-administration, we will measure the cardiovascular and subjective effects of repeated cocaine administration and cocaine craving under each vigabatrin maintenance condition. Determining vigabatrin's effects on a range of smoked cocaine doses will provide essential data on the mechanism of the vigabatrin-cocaine interaction.
Recruitment & Eligibility
- Status
- TERMINATED
- Sex
- All
- Target Recruitment
- 1
- Meets DSM-IV criteria for current cocaine abuse
- Average use of smoked cocaine is at least 2x/week for past 6 mos; currently spends at least $70 per week on cocaine
- Has patterns of smoked cocaine use in terms of frequency and amounts which parallel or exceed those administered in the study
- Age 21-45
- Able to give informed consent, and comply with study procedures
- Agrees to practice an effective form of contraception
- Current seizure disorder or heart disease
- Currently meeting DSM-IV criteria for all major psychiatric/psychotic disorders. Volunteers with a history of depression or psychosis will also be excluded (p. 43, Investigator's brochure)
- Dependence on substances other than cocaine or nicotine
- Request for drug treatment
- Judged to be noncompliant with study protocol
- Clinical laboratory tests outside normal limits that are unacceptable to the study physician (e.g., BP > 140/90; BUN, creatinine, LFTs > 1.5 ULN; hematocrit < 34 for women, < 36 for men; pseudocholinesterase deficiency)
- Current parole or probation
- Recent history of significant violent or suicidal behavior
- Pregnancy or lactation
- Baseline visual field defects
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Vigabatrin, cocaine Cocaine - Vigabatrin, cocaine Vigabatrin - placebo, cocaine Cocaine - placebo, cocaine Vigabatrin -
- Primary Outcome Measures
Name Time Method Cardiovascular effects Cravings Cocaine Administration Subjective effects
- Secondary Outcome Measures
Name Time Method
Trial Locations
- Locations (1)
Irving Center for Clinical Research
🇺🇸New York, New York, United States