Anton 2011.

Methods	Randomised placebo‐controlled double‐blind trial
Participants	150 participants; mean age 44.5 years; 82% male; 88% Caucasian; 23% heavy drinking days on average Inclusion criteria: meeting DSM‐IV criteria for alcohol dependence; consuming on average five or more standard drinks per day for men or four or more drinks per day for women; being able to maintain sobriety for four days before randomisation, living near the study site in a stable living situation Exclusion criteria: meeting DSM‐IV criteria for other substance dependence (except nicotine); using illicit drugs in the past 30 days or having a positive urine drug screen; meeting DSM‐IV criteria for an Axis I disorder; having current suicidal or homicidal ideation; needing maintenance with psychotropic or anticonvulsant medication; having unstable medical conditions; having liver enzyme (ALT and AST) levels greater than three times normal; using disulfiram, acamprosate or either of the study medications within the past 30 days; taking an opioid medication on a routine basis; having legal charges pending; having undergone more than one previous inpatient medical detoxification treatment
Interventions	(1) Naltrexone plus gabapentin, 50 participants; (2) naltrexone plus placebo, 50 participants; (3) placebo plus placebo, 50 participants Drug dose: naltrexone 50 mg/d; gabapentin up to 1200 mg/d Participants provided sessions of combined behavioural intervention therapy using the behavioural intervention treatment manual of the COMBINE study (Miller 2004), which combined cognitive‐behavioural therapy, motivation interviewing and 12‐step facilitation techniques in a client needs–based approach Setting: outpatient Duration: 16 weeks (gabapentin added for first six weeks). Country of origin: USA
Outcomes	Primary outcome measures: time to relapse to drinking; symptoms such as difficulty falling asleep and/or staying asleep, irritability and nervousness, as measured by a symptom checklist and specific scales Secondary outcome measures: percentage of days drinking; drinks per drinking day; retention in the protocol; craving for alcohol; CDT and GGT measured as change from baseline; psychological and general health functioning as measured by Beck Anxiety and Depression scales; liver function tests (ALT and AST)
Notes	This study has been included for the only six weeks of gabapentin use
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Random allocation stated. No further details provided
Allocation concealment (selection bias)	Unclear risk	Method of concealment not described
Incomplete outcome data (attrition bias) All outcomes	Low risk	Methods applied to account for missing data
Blinding of participants and personnel (performance bias) all outcomes	Unclear risk	Double‐dummy placebo‐controlled medication design applied. Medication dispensed in identically packaged blister cards. No specific reference made to blindness of participants and personnel
Blinding of outcome assessment (detection bias) subjective	Unclear risk	Double‐dummy placebo‐controlled medication design applied. Medication dispensed in identically packaged blister cards. No specific reference made to blindness of outcome assessors
Blinding of outcome assessment (detection bias) objective	Low risk	Double‐dummy placebo‐controlled medication design applied. Medication dispensed in identically packaged blister cards. No further details provided Outcome measurement not likely to be influenced by lack of blinding