The findings of this review suggest that oral naltrexone did not perform better than treatment with placebo or no pharmacological agent with respect to the number of participants re-incarcerated during the study period. If oral naltrexone is compared with other pharmacological treatments such as benzodiazepine and buprenorphine, no statistically significant difference was found. The percentage of people retained in treatment in the included studies is however low (28%). The conclusion of this review is that the studies conducted have not allowed an adequate evaluation of oral naltrexone treatment in the field of opioid dependence. Consequently, maintenance therapy with naltrexone cannot yet be considered a treatment which has been scientifically proved to be superior to other kinds of treatment.
A naltrexone double blind placebo controlled study in Israel.
In a double blind study, out of 31 newly abstinent patients who underwent opioid free detoxification, 15 were started on the opiate antagonist Naltrexone for 2 months, and 16 were put on placebo for the same period. Given Naltrexone's known efficacy in blocking euphorigenic effects of opioid intake, and in decreasing cravings for the drug, the authors have tried to assess eventual drug taking, specifically in the context of suburban housing projects, and evaluate the rate of retention in a rehabilitative program for both the Naltrexone and placebo groups. An Opioid free condition was followed up for a year, also respecting double blind conditions. Naltrexone did not appear to be superior to the placebo with regards to retention rate. In the Naltrexone group (n = 15), 9 finished the two-month treatment, and 8 remained opioid-free for a year. In the placebo group (n = 16), 8 finished the 2 month trial and 6 remained opioid-free for a year. Naltrexone blocked opioid-induced euphoria and decreased the craving for opium, but it did not inhibit drug usage. The retention rate registered during the course of the study, as well as an opioid-free condition in the follow-up year, correlated with a patient profile defined by good social functioning and stable relationships. The inherent methodological limitations of this study did not allow for the discrimination of the role of non-pharmacological factors, such as psychotherapy, supportive family framework, community assistance, and staff motivation, concerning the clinical results. Further investigation of Naltrexone in larger samples is needed.