Gonzalez 2007 arm b.
| Methods | Randomised placebo‐controlled trial | |
| Participants | Participants: 76; mean age 37 years; male 76%; Caucasian 70%; unemployed 54% Reporting cocaine use: 100% Route of administration: smoked 73% Mean days of cocaine use during the past 30 days: 16 Inclusion criteria: fulfilling DSM‐IV criteria for current opioid dependence and weekly use of cocaine within a month before study entry Exclusion criteria: major cardiovascular, renal, endocrine or hepatic disorder; history of psychotic disorder or schizophrenia, or current suicidal ideation; pregnant or breast feeding women |
|
| Interventions | (1) gabapentin 2400 mg/d then tapered, 26 participants; (2) placebo, 25 participants
Outpatient Duration: 10 weeks Country of origin: USA |
|
| Outcomes | Dropout; Use of cocaine; Compliance | |
| Notes | Supported by the National Institute on Drug Abuse grants K23DA14331 (GG), K05DA00454 (TRK), R01‐DA05626, P50‐DA12762 and the Veterans Administration Mental Illness Research, Education and Clinical Center (MIRECC) Conflict of interest: not reported |
|
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Information not reported |
| Allocation concealment (selection bias) | Low risk | Quote: "Only the data manager who did not have direct contact with research subjects during their assessments and the pharmacist preparing the study medication were aware of the allocation, and the principal investigator kept the medication assignment code in a sealed envelope for access in case of medical emergency" |
| Blinding of participants and personnel (performance bias) objective outcomes | Low risk | Study declared as double‐blind Quote: "Tiagabine (Gabitril), gabapentin (Neurontin) and placebo were placed in identical capsules" |
| Blinding of participants and personnel (performance bias) subjective outcomes | Low risk | Study declared as double‐blind Quote: "Tiagabine (Gabitril), gabapentin (Neurontin) and placebo were placed in identical capsules" |
| 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 | Quote: "We conducted the primary analyses on the total intent‐to‐treat sample (N = 76)" |
| 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 |