Injectable, sustained-release naltrexone for the treatment of opioid dependence: a randomized, placebo-controlled trial. Anesthesia-assisted vs buprenorphine- or clonidine-assisted heroin detoxification and naltrexone induction: a randomized trial. Comparison of pharmacological treatments for opioid-dependent adolescents: a randomized controlled trial. Follow-up after a six-month maintenance period on naltrexone versus placebo in heroin addicts. Three methods of opioid detoxification in a primary care setting. A randomized trial. Reducing hospital presentations for opioid overdose in patients treated with sustained release naltrexone implants. Naltrexone shortened opioid detoxification with buprenorphine. A naltrexone double blind placebo controlled study in Israel. Maintenance treatment with buprenorphine and naltrexone for heroin dependence in Malaysia: a randomised, double-blind, placebo-controlled trial. Controlled, randomized trial in maintenance treatment of intravenous buprenorphine dependence with naltrexone, methadone or buprenorphine: a novel study. Naltrexone reduces the relative reinforcing value of nicotine in a cigarette smoking choice paradigm.
Oral naltrexone can completely antagonize the effects produced by opioid agonists. However, poor compliance with naltrexone has been a major obstacle to the effective treatment of opioid dependence.
                To evaluate the safety and efficacy of a sustained-release depot formulation of naltrexone in treating opioid dependence.
                Randomized, double-blind, placebo-controlled, 8-week trial conducted at 2 medical centers.
                Sixty heroin-dependent adults.
                Participants were stratified by sex and years of heroin use (> or = 5 vs < 5) and then were randomized to receive placebo or 192 or 384 mg of depot naltrexone. Doses were administered at the beginning of weeks 1 and 5. All participants received twice-weekly relapse prevention therapy, provided observed urine samples, and completed other assessments at each visit.
                Retention in treatment and percentage of opioid-negative urine samples.
                Retention in treatment was dose related, with 39%, 60%, and 68% of patients in the placebo, 192 mg of naltrexone, and 384 mg of naltrexone groups, respectively, remaining in treatment at the end of 2 months. Time to dropout had a significant main effect of dose, with mean time to dropout of 27, 36, and 48 days for the placebo, 192 mg of naltrexone, and 384 mg of naltrexone groups, respectively. The percentage of urine samples negative for opioids, methadone, cocaine, benzodiazepines, and amphetamine varied significantly as a function of dose. When the data were recalculated without the assumption that missing urine samples were positive, a main effect of group was not found for any drugs tested except cocaine, where the percentage of cocaine-negative urine samples was lower in the placebo group. Adverse events were minimal and generally mild. This formulation of naltrexone was well tolerated and produced a robust, dose-related increase in treatment retention.
                These data provide new evidence of the feasibility, efficacy, and tolerability of long-lasting antagonist treatments for opioid dependence. Rapid opioid detoxification with opioid antagonist induction using general anesthesia has emerged as an expensive, potentially dangerous, unproven approach to treat opioid dependence.
                To determine how anesthesia-assisted detoxification with rapid antagonist induction for heroin dependence compared with 2 alternative detoxification and antagonist induction methods.
                A total of 106 treatment-seeking heroin-dependent patients, aged 21 through 50 years, were randomly assigned to 1 of 3 inpatient withdrawal treatments over 72 hours followed by 12 weeks of outpatient naltrexone maintenance with relapse prevention psychotherapy. This randomized trial was conducted between 2000 and 2003 at Columbia University Medical Center's Clinical Research Center. Outpatient treatment occurred at the Columbia University research service for substance use disorders. Patients were included if they had an American Society of Anesthesiologists physical status of I or II, were without major comorbid psychiatric illness, and were not dependent on other drugs or alcohol.
                Anesthesia-assisted rapid opioid detoxification with naltrexone induction, buprenorphine-assisted rapid opioid detoxification with naltrexone induction, and clonidine-assisted opioid detoxification with delayed naltrexone induction.
                Withdrawal severity scores on objective and subjective scales; proportions of patients receiving naltrexone, completing inpatient detoxification, and retained in treatment; proportion of opioid-positive urine specimens.
                Mean withdrawal severities were comparable across the 3 treatments. Compared with clonidine-assisted detoxification, the anesthesia- and buprenorphine-assisted detoxification interventions had significantly greater rates of naltrexone induction (94% anesthesia, 97% buprenorphine, and 21% clonidine), but the groups did not differ in rates of completion of inpatient detoxification. Treatment retention over 12 weeks was not significantly different among groups with 7 of 35 (20%) retained in the anesthesia-assisted group, 9 of 37 (24%) in the buprenorphine-assisted group, and 3 of 34 (9%) in the clonidine-assisted group. Induction with 50 mg of naltrexone significantly reduced the risk of dropping out (odds ratio, 0.28; 95% confidence interval, 0.15-0.51). There were no significant group differences in proportions of opioid-positive urine specimens. The anesthesia procedure was associated with 3 potentially life-threatening adverse events.
                These data do not support the use of general anesthesia for heroin detoxification and rapid opioid antagonist induction. The prevalence of heroin and other opioid use has markedly increased among adolescents in the last decade; however, virtually no research has been conducted to identify effective treatments for this population.
                To evaluate the relative efficacy of 2 pharmacotherapies, the partial opioid agonist buprenorphine hydrochloride and the centrally active alpha(2)-adrenergic blocker clonidine hydrochloride, in the detoxification of opioid-dependent adolescents.
                A double-blind, double-dummy, parallel-groups randomized controlled trial conducted in a university-based research clinic from October 2001 to December 2003. Patients were a volunteer sample of 36 adolescents who met DSM-IV criteria for opioid dependence (ages 13-18 years eligible).
                Participants were randomly assigned to a 28-day, outpatient, medication-assisted withdrawal treatment with either buprenorphine or clonidine. Both medications were provided along with thrice weekly behavioral counseling and incentives contingent on opiate abstinence. Postdetoxification, all participants were offered the opportunity for continued treatment with the opiate antagonist, naltrexone hydrochloride.
                Treatment retention, opiate abstinence, and human immunodeficiency virus risk behavior, along with measures of withdrawal and medication effects.
                A significantly greater percentage of adolescents who received buprenorphine were retained in treatment (72%) relative to those who received clonidine (39%) (P<.05). For those in the buprenorphine group, a significantly higher percentage of scheduled urine test results were opiate negative (64% vs 32%; P = .01). Participants in both groups reported relief of withdrawal symptoms and drug-related human immunodeficiency virus risk behavior. Those in the buprenorphine condition generally reported more positive effects of the medication. No evidence of opioid intoxication or psychomotor impairment was observed. Sixty-one percent of participants in the buprenorphine condition and 5% of those in the clonidine group initiated treatment with naltrexone.
                Combining buprenorphine with behavioral interventions is significantly more efficacious in the treatment of opioid-dependent adolescents relative to combining clonidine and behavioral interventions. Naltrexone and placebo as adjuvant treatment of opioid dependence were compared in a double-blind, controlled clinical trial in 50 heroin addicts. The overall efficacy was assessed by the degree of treatment acceptance, percentage of relapse in heroin consumption, presence of side effects, and overall retention on naltrexone. A total of 50 patients of both sexes, aged from 18 to 30 years, who fulfilled DSM-III-R criteria for opioid dependence were included in the study. All patients completed detoxification with clonidine on an inpatient basis for 2 weeks and subsequently, on an out-patient basis, received oral naltrexone (350 mg per week) for a month. At the beginning of the second month patients were randomly allocated to treatment with naltrexone (28 patients) or placebo (22 patients) until a 6-month treatment period in a double-blind fashion had been completed. During the study period (1 year) all patients followed the same therapeutic schedule. Patients in both groups were comparable in terms of socio-demographic data and toxicological history. The efficacy of naltrexone was not superior to that of placebo as there were no significant differences in acceptance of treatment, retention rates, opioid and other drug consumption, drug compliance or side effects. Opioid detoxification in a primary care setting followed by ongoing substance abuse treatment may be appropriate for selected opioid-dependent patients.
                To compare three pharmacologic protocols for opioid detoxification in a primary care setting.
                Randomized, double-blind clinical trial with random assignment to treatment protocols.
                A free-standing primary care clinic affiliated with drug treatment programs.
                162 heroin-dependent patients.
                Three detoxification protocols: donidine, combined donidine and naltrexone, and buprenorphine.
                Successful detoxification (that is, when study participants received a full opioid-blocking dose [50 mg] of naltrexone), treatment retention (8 days), and withdrawal symptoms.
                Overall, 65% of participants (36 of 55) who received clonidine, 81% (44 of 54) who received combined clonidine and naltrexone, and 81% (43 of 53) who received buprenorphine were successfully detoxified. Retention did not differ significantly across the groups: 65% of participants (36 of 55) who received clonidine, 54% (29 of 54) who received combined clonidine and naltrexone, and 60% (32 of 53) who received buprenorphine. Participants who received buprenorphine had a significantly lower mean withdrawal symptom score than those who received clonidine or combined clonidine and naltrexone.
                Participants in the combined clonidine and naltrexone group and those in the buprenorphine group were more likely to complete detoxification, although retention at 8 days did not differ among the groups. Participants who were assigned to the buprenorphine group experienced less severe withdrawal symptoms than those assigned to the other two groups. Non-fatal overdoses represent a significant morbidity for regular heroin users. Naltrexone is an opioid antagonist capable of blocking the effects of heroin, thereby preventing accidental overdose. However, treatment with oral naltrexone is often associated with non-compliance. An alternative is the use of a sustained release preparation of naltrexone. The aim of this study was to assess the change in number of opioid and other drug overdoses in a large cohort of heroin dependent persons (n=361; 218 males) before and after treatment with a sustained release naltrexone implant. A sub-group of this cohort (n=146; 83 males) had previously received treatment with oral naltrexone, which also allowed a comparison of overdoses pre- and post-oral and also post-implant treatments.
                We used a pre-post design, with data prospectively collected via the West Australian Health Services Research Linked Database, and the Emergency Department Information System. Participants were treated under the Australian Therapeutic Goods Administration's special access guidelines.
                Most (336, 93%) of the cohort was in one or both databases. We identified 21 opioid overdoses involving 20 persons in the 6 months pre-treatment that required emergency department presentation or hospital admission: none were observed in the 6 months post-treatment. This is consistent with the existing pharmacokinetic data on this implant, which indicates maintenance of blood naltrexone levels at or above 2 ng/ml for approximately 6 months. A reduced number of opioid overdoses were also observed 7-12 months post-implant. The study found a significant increase in sedative "overdoses", some of which occurred in the 10 days following implant treatment and were likely associated with opioid withdrawal and/or implant treatment. For those previously treated with oral naltrexone, more opioid overdoses occurred in both the 6-months prior to and after oral compared to the 6-months post-implant treatment.
                The findings support the clinical efficacy of this sustained release naltrexone implant in preventing opioid overdose. However, given the high prevalence of poly-substance use among dependent heroin users, programs offering this type of treatment should also focus on preventing, detecting and managing poly-substance use. This double-blind, randomized, placebo-controlled clinical trial evaluated the impact on withdrawal symptoms of (i) combining naltrexone with a 4-day buprenorphine taper for short opioid detoxification (NB Group), compared to (ii) using a 4-day buprenorphine taper alone, followed by naltrexone on day 8 (PB Group). Sublingual buprenorphine was administered on days 1-4 (26 mg total). For the NB Group (n = 32) escalating doses of oral naltrexone were given on days 2-8 (placebo day 1). For the PB Group (n = 28) placebo was given on days 1-7 and naltrexone on day 8. Main outcome measures were Observed Opioid Withdrawal scores (OOW, 0-30) and use of medications to treat opioid withdrawal. Of 32 patients in the NB group, 59% experienced clinically relevant withdrawal (defined as OOW > or = 5) on day 2, but, after day 5, none experienced withdrawal. In the PB group, the number of patients experiencing withdrawal increased over time. The first naltrexone dose induced comparable withdrawal in both groups: peak OOW scores were (mean +/- SD) 5.2 +/- 3.3 on day 2 for the NB group, and 4.0 +/- 3.9 on day 8 for the PB group (NS), though, on day 2, 7 patients dropped out in the NB group and none in the PB group, while only one patient dropped out in the PB group on day 8. Throughout the 8-day study, patients in both groups received similar amount of adjunct medication: 0.64 +/- 0.07 mg (NB group) of clonidine vs 0.73 +/- 0.15 mg (PB group; NS). Only 25% of patients required use of sedatives (up to 20 mg diazepam). Starting naltrexone on day 2 appeared to abolish withdrawal symptoms after day 5 and, thus, to shorten the duration of withdrawal symptoms. Peak withdrawal symptoms after naltrexone were of moderate intensity, suggesting that naltrexone combined with buprenorphine is an acceptable and safe treatment for shortened opioid detoxification and induction of naltrexone maintenance. 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. Expansion of access to effective treatments for heroin dependence is a worldwide health priority that will also reduce HIV transmission. We compared the efficacy of naltrexone, buprenorphine, and no additional treatment, in patients receiving detoxification and subsequent drug counselling, for maintenance of heroin abstinence, prevention of relapse, and reduction of HIV risk behaviours.
                126 detoxified heroin-dependent patients, from an outpatient research clinic and detoxification programme in Malaysia, were randomly assigned by a computer-generated randomisation sequence to 24 weeks of manual-guided drug counselling and maintenance with naltrexone (n=43), buprenorphine (n=44), or placebo (n=39). Medications were administered on a double-blind and double-dummy basis. Primary outcomes, assessed by urine testing three times per week, were days to first heroin use, days to heroin relapse (three consecutive opioid-positive urine tests), maximum consecutive days of heroin abstinence, and reductions in HIV risk behaviours over 6 months. The study was terminated after 22 months of enrolment because buprenorphine was shown to have greater efficacy in an interim safety analysis. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00383045.
                We observed consistent, linear contrasts in days to first heroin use (p=0.0009), days to heroin relapse (p=0.009), and maximum consecutive days abstinent (p=0.0007), with all results best for buprenorphine and worst for placebo. Buprenorphine was associated with greater time to first heroin use than were naltrexone (hazard ratio 1.87 [95% CI 1.21-2.88]) or placebo (2.02 [1.29-3.16]). With buprenorphine, we also recorded significantly greater time to heroin relapse (2.17 [1.38-3.42]), and maximum consecutive days abstinent than with placebo (mean days 59 [95% CI 43-76] vs 24 [13-35]; p=0.003); however, for these outcomes, differences between buprenorphine and naltrexone were not significant. Differences between naltrexone and placebo were not significant for any outcomes. HIV risk behaviours were significantly reduced from baseline across all three treatments (p=0.003), but the reductions did not differ significantly between the three groups.
                Our findings lend support to the widespread dissemination of maintenance treatment with buprenorphine as an effective public-health approach to reduce problems associated with heroin dependence. To test the effect of a 50-mg day-1 dose of naltrexone in the maintenance treatment of intravenous-buprenorphine dependence in comparison with a 50-mg day-1 dose of methadone and also a 5-mg day-1 dose of buprenorphine over a 24-week treatment period.
                Two hundred and four intravenous-buprenorphine-dependent patients who met the DSM-IV criteria for opioid dependence were randomized to three equal groups and were treated in a clinic in Iran where they were also offered a weekly 0.5-h counselling session, in 2002.
                The mean age was 31.2 years (range 17-53). The majority [63.2%] was between 20 and 34 years of age. The educational level of most of them [55.4%] was between 6 and 12 years of study. Completion rates by groups were 83.8% for the 50-mg dose methadone group, 58.8% for the 5-mg dose buprenorphine group and 20.6% for the 50-mg dose naltrexone group (P = 0.000). Retention in the 50-mg methadone group was significantly better than in the 5-mg dose buprenorphine group (P = 0.001) and the 50-mg dose naltrexone group (P = 0.000). Retention in the 5-mg buprenorphine group was significantly better than in the 50-mg naltrexone dose group (P = 0.000).
                Evaluation of the Iranian experience on this subject may be useful for other countries. Human behavioral pharmacology studies can examine how medications that target different neurotransmitter systems influence different aspects of smoking. Naltrexone and bupropion have been shown to alter ad lib smoking behavior; however, medication effects on nicotine reward in a cigarette choice paradigm have yet to be investigated.
                This study explored the effects of an acute dose of naltrexone, bupropion, or placebo on the relative reinforcing value of nicotine from cigarette smoking using new nicotine and de-nicotinized (Quest, 0.6 and 0.05 mg = "denicotinized") cigarettes.
                In a double-blind, within-subjects design, 26 dependent smokers participated in three experimental cigarette smoking sessions following pretreatment with either naltrexone (50 mg), bupropion (300 mg), or placebo. After medication administration and 2 h of monitored deprivation from cigarettes and food, participants rated their responses to the initial exposure to the cigarettes and then participated in four choice sessions over a 2-h period during which they could take four puffs from either cigarette.
                The relative reinforcing value of nicotine, as measured by the number of nicotine puffs chosen out of 16, was significantly lower following naltrexone compared to placebo. There were no effects of an acute dose of bupropion on nicotine choices.
                These results suggest that naltrexone may reduce the relative reinforcing effects of nicotine via cigarette smoking and support ongoing investigation of opioid antagonists as potential smoking cessation pharmacotherapies.
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.