RESUMO
AIMS: The purpose of the study was to assess whether fluoxetine would enhance retention in a naltrexone (NTX) treatment programme. DESIGN: Randomized clinical trial. SETTING: The clinical trial was conducted in two Drug Dependence Centres (DCs) of the Basque Country, Spain over a 1-year period. These DCs routinely used naltrexone as part of their treatment. PARTICIPANTS: A total of 112 heroin addicts included in a naltrexone treatment programme were randomly allocated to two groups of 56 patients each. INTERVENTION: One group received 20 mg/24 h of fluoxetine for the first 6 months, while the remaining 56 patients were used as controls. No placebo was used. MEASUREMENTS: Retention rates and hazard functions were estimated. The risk difference and relative risk were also calculated at 6 and 12 months. FINDINGS: The survival functions showed significantly higher retention rates in the fluoxetine group than among the controls. The risk difference at both 6 months (RD6 = 0.23, CI 95% = 0.06-0.42) and 12 months (RD12 = 0.21, CI 95% = 0.09-0.39) favoured the fluoxetine group, with a greater dropout risk at both times among the controls (RR6 = 1.81, CI 95% = 1.11-2.94; RR12 = 1.46, CI 95% = 1.04-2.04). CONCLUSIONS: The study showed that the combination of fluoxetine and naltrexone produced significantly greater retention than in patients given only naltrexone. Placebo-controlled trials are warranted to assess how far this reflects a specific pharmacological effect.
