Somoza 2013.

Methods	Multi‐site randomised placebo‐controlled trial
Participants	Participants: 186 treatment‐seeking with cocaine dependence; mean age 45 years; male 66.5%; African American 60%, white 31% Reporting cocaine use: 100% Route of cocaine administration: smoked or intravenous 85%, nasal 15% Frequency of cocaine use during the last 30 days before screening < 18 days: 67.5% Inclusion criteria: at least 18 years old, normal visual fields as measured by a Humphrey field analyser, in good physical health as determined by the results of a medical history, physical examination, electrocardiogram and standard laboratory tests; met DSM‐IV criteria for cocaine dependence and hd at least 1 positive (benzoylecgonine [BE] level 300 ng/mL) urine drug screen during the 14‐day baseline Exclusion criteria: individuals who required detoxification from alcohol, who had been court‐ordered to seek cocaine‐dependence treatment or who met DSM‐IV criteria for dependence for any substance other than cocaine, alcohol, nicotine or marijuana. Pregnant and lactating women and women unwilling to use an adequate method of birth control; patients who had ever taken vigabatrin, had received electroconvulsive therapy within 3 months of randomisation or had been enrolled in an opioid substitution programme in the past 2 months. Patients who had taken a drug with known major organ toxic effects, including retinotoxic effects, within 30 days of randomisation or who had clinically significant ophthalmological disease
Interventions	(1) twice‐daily doses of vigabatrin (total dosage 3.0 g/d), participants 92; (2) placebo, participants 94 All participants received weekly computerised cognitive‐behavioural therapy at 21 plus biweekly half‐hour individual sessions with a counselor Setting: outpatient Follow‐up: duration of the trial: 12 weeks; follow‐up: 24 weeks Country of origin: USA
Outcomes	Cocaine abstinence, Cocaine use, Craving (as assessed by BSCS), Addiction Severity and Substance Clinical Global Impression (SCGI) scores; Adverse events; Compliance
Notes	Funding and support for this study were provided by Catalyst Pharmaceutical Partners, Inc. The study medication and matching placebo were provided by the company at no cost. The sponsor provided funding to a clinical research organisation, Health Decisions (Durham, NC), which provided day‐to‐day data collection management and analysis and initial interpretation of data Conflict of interest: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "those meeting study criteria were randomized in a 1:1 ratio to vigabatrin or placebo, stratified by sex, primary route of cocaine administration (ie, smoked or intravenous vs nasal), and frequency of cocaine use during the last 30 days before screening (18 vs18 days)"
Allocation concealment (selection bias)	Unclear risk	Information not reported
Blinding of participants and personnel (performance bias) objective outcomes	Low risk	Study declared as double‐blind Quote: "Vigabatrin and its matching placebo were supplied as white, film‐coated, capsule‐shaped 500‐mg tablets with a bisect on one side. They were custom manufactured for Catalyst Pharmaceutical Partners, Inc"
Blinding of participants and personnel (performance bias) subjective outcomes	Low risk	Study declared as double‐blind Quote: "Vigabatrin and its matching placebo were supplied as white, film‐coated, capsule‐shaped 500‐mg tablets with a bisect on one side. They were custom manufactured for Catalyst Pharmaceutical Partners, Inc"
Blinding of outcome assessment (detection bias) objective outcomes	Low risk	Information not reported Comment: objective outcomes unlikely to be biased by lack of blinding
Blinding of outcome assessment (detection bias) subjective outcomes	Unclear risk	Information not reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	Analysis performed on an intention‐to‐treat basis
Selective reporting (reporting bias)	Low risk	Study protocol is not available, but published reports include all expected outcomes, including those that were prespecified in the Methods section