Title : Subcutaneous naltrexone implants for relapse prevention after opiate detoxification A one year follow up study
Background: Since the year 2000, oral Naltrexone in combination with Cognitive Behavioural Therapy (CBT) has been implemented at our clinic for relapse prevention after opiate detoxification. Naltrexone implants were introduced in 2003. All patients receive a 6-week or 2-month implant upon detoxification and are offered 6-week, 2-month or 6–month repeat implants, depending on the patient’s wish and availability of implants. A prescription for oral Naltrexone is also an option. The 6-month implants were no longer available after December 2008. Only 2-month Naltrexone implants have been available since that time.
Aim: Evaluation of the efficacy of Naltrexone implants in our relapse prevention program after opiate detoxification and to report of complication rate of this treatment.
Method: Retrospective descriptive study: all the patients who received a Naltrexone implant after detoxification during the study period (May 2003–January 2009) were included in the study. We used patient notes, the number of implants, the duration of implant treatment. The types of implants were counted, and complications were noted.
Results: A total of 186 patients (148 men, 38 women) were detoxified and received at least 1 implant.
We used 535 implants (74 Wedgwood 6-week implants, 99 O’Neil 6-month implants and 362 of the 2-month implants). The patients used an average of 3.3 implants each (range 1–18). The duration of implant use averaged 7.66 months (range 1.5–38 months). Patients who had 6-week and 2-month implants (N=122) were under protection of an implant for an average of 5.11 months (range 1.5–36 months). Patients with a 6-month implant (N=64) were under protection of an implant for an average of 12.25 months (range 6–38 months). The difference is significant at p < 0.001.
Conclusion: Patients with subcutaneous Naltrexone implants had a very low relapse rate of 1.3% while using implants. Patients who had at least one 6-month implant remained under the protection of implants significantly longer then patients who used 6-week and 2-month implants. Major and minor complications were infrequent. At one-year follow-up, 58% of patients were opiate abstinent.