The efficacy of naltrexone in preventing reabuse of heroin after detoxification

Empirically contrasting urine drug screening-based opioid use disorder treatment outcome definitions

BACKGROUND AND AIMS

A lack of consensus on the optimal outcome measures to assess opioid use disorder (OUD) treatment efficacy and their precise definition and computation has hampered the pooling of research data for evidence synthesis and meta-analyses. This study aimed to empirically contrast multiple clinical trial definitions of treatment success by applying them to the same dataset.

METHODS

Data analysis used a suite of functions, developed as a software package for the R language, to operationalize 61 treatment outcome definitions based on urine drug screening (UDS) results. Outcome definitions were derived from clinical trials that are among the most influential in the OUD treatment field. Outcome functions were applied to a harmonized dataset from three large-scale National Drug Abuse Treatment Clinical Trials Network (CTN) studies, which tested various medication for OUD (MOUD) options (n = 2492). Hierarchical clustering was employed to empirically contrast outcome definitions.

RESULTS

The optimal number of clusters identified was three. Cluster 1, comprising eight definitions focused on detecting opioid-positive UDS, did not include missing UDS in outcome calculations, potentially resulting in inflated rates of treatment success. Cluster 2, with the highest variability, included 10 definitions characterized by strict criteria for treatment success, relying heavily on UDS results from either a brief period or a single study visit. The 43 definitions in Cluster 3 represented a diverse range of outcomes, conceptualized as measuring abstinence, use reduction and relapse. These definitions potentially offer more balanced measures of treatment success or failure, as they avoid the extreme methodologies characteristic of Clusters 1 and 2.

CONCLUSIONS

Clinical trials using urine drug screening (UDS) for objective substance use assessment in outcome definitions should consider (1) incorporating missing UDS data in outcome computation and (2) avoiding over-reliance on UDS data confined to a short time frame or the occurrence of a single positive urine test following a period of abstinence.

Treatment-Resistant Depression (TRD): Is the Opioid System Involved?

About 30% of major depression disorder patients fail to achieve remission, hence being diagnosed with treatment-resistant major depression (TRD). Opium had been largely used effectively to treat depression for centuries, but when other medications were introduced, its use was discounted due to addiction and other hazards. In a series of previous studies, we evaluated the antinociceptive effects of eight antidepressant medications and their interaction with the opioid system. Mice were tested with a hotplate or tail-flick after being injected with different doses of mianserin, mirtazapine, trazodone, venlafaxine, reboxetine, moclobemide, fluoxetine, or fluvoxamine to determine the effect of each drug in eliciting antinociception. When naloxone inhibited the antinociceptive effect, we further examined the effect of the specific opioid antagonists of each antidepressant drug. Mianserin and mirtazapine (separately) induced dose-dependent antinociception, each one yielding a biphasic dose-response curve, and they were antagonized by naloxone. Trazodone and venlafaxine (separately) induced a dose-dependent antinociceptive effect, antagonized by naloxone. Reboxetine induced a weak antinociceptive effect with no significant opioid involvement, while moclobemide, fluoxetine, and fluvoxamine had no opioid-involved antinociceptive effects. Controlled clinical studies are needed to establish the efficacy of the augmentation of opiate antidepressants in persons with treatment-resistant depression and the optimal dosage of drugs prescribed.

Relative effectiveness of medications for opioid-related disorders: A systematic review and network meta-analysis of randomized controlled trials

INTRODUCTION

Several pharmacotherapeutic interventions are available for maintenance treatment for opioid-related disorders. However, previous meta-analyses have been limited to pairwise comparisons of these interventions, and their efficacy relative to all others remains unclear. Our objective was to unify findings from different healthcare practices and generate evidence to strengthen clinical treatment protocols for the most widely prescribed medications for opioid-use disorders.

METHODS

We searched Medline, EMBASE, PsycINFO, CENTRAL, and ClinicalTrials.gov for all relevant randomized controlled trials (RCT) from database inception to February 12, 2022. Primary outcome was treatment retention, and secondary outcome was opioid use measured by urinalysis. We calculated risk ratios (RR) and 95% credible interval (CrI) using Bayesian network meta-analysis (NMA) for available evidence. We assessed the credibility of the NMA using the Confidence in Network Meta-Analysis tool.

RESULTS

Seventy-nine RCTs met the inclusion criteria. Due to heterogeneity in measuring opioid use and reporting format between studies, we conducted NMA only for treatment retention. Methadone was the highest ranked intervention (Surface Under the Cumulative Ranking [SUCRA] = 0.901) in the network with control being the lowest (SUCRA = 0.000). Methadone was superior to buprenorphine for treatment retention (RR = 1.22; 95% CrI = 1.06-1.40) and buprenorphine superior to naltrexone (RR = 1.39; 95% CrI = 1.10-1.80). However, due to a limited number of high-quality trials, confidence in the network estimates of other treatment pairs involving naltrexone and slow-release oral morphine (SROM) remains low.

CONCLUSION

All treatments had higher retention than the non-pharmacotherapeutic control group. However, additional high-quality RCTs are needed to estimate more accurately the extent of efficacy of naltrexone and SROM relative to other medications. For pharmacotherapies with established efficacy profiles, assessment of their long-term comparative effectiveness may be warranted.

TRIAL REGISTRATION

This systematic review has been registered with PROSPERO (https://www.crd.york.ac.uk/prospero) (identifier CRD42021256212).

The effects of naltrexone on retention in treatment and being opioid-free in opioid-dependent people: A systematic review and meta-analysis

BACKGROUND

Opioid dependency is a chronic relapsing disorder for which different therapeutically interventions have been developed. Naltrexone is a non-selective opioid antagonist that can be utilized for maintenance therapy in opioid dependency. In this systematic review, we aimed to evaluate the effects of naltrexone on retention in treatment and being opioid-free.

METHODS

We systematically searched PubMed and EMBASE databases up to February 5, 2022, using the following keywords: "Naltrexone," "Substance abuse," "Drug abuse," "Opiate-related disorder," and "Opioid dependence." Studies that included opiate-dependent individuals who were treated with naltrexone and assessed retention in treatment or being opioid-free were included. Two authors independently used the Cochrane risk-of-bias tool for quality assessment. A random effect model in Comprehensive Meta-Analysis software was used for the conduction of the meta-analysis. We performed subgroup analysis to evaluate the effects of naltrexone types on outcomes.

RESULTS

Eighteen studies, including 2,280 participants met our inclusion criteria. The duration of treatment ranged from 21 days to 24 months. The retention in treatment with naltrexone was 63% higher than controls (odds ratio (OR): 1.64 [95% confidence interval (CI), 0.78-3.44]. The OR for being opioid-free was 1.63 (95% CI, 0.57-4.72). Injectable naltrexone was significantly effective on retention in treatment (OR 1.86; 95% CI, 1.17-2.98).

CONCLUSIONS

We found that naltrexone could be useful for retention in treatment and being opioid-free, however, the findings were not significant. Further high-quality and large-scale observational studies are recommended.

Developmental Considerations for the Use of Naltrexone in Children and Adolescents

Naltrexone (NTX) is a well-tolerated drug with a wide safety margin and mechanism of action that affords use across a wide variety of indications in adults and children. By antagonizing the opioid reward system, NTX can modulate behaviors that involve compulsivity or impulsivity, such as substance use, obesity, and eating disorders. Evidence regarding the disposition and efficacy of NTX is mainly derived from adult studies of substance use disorders and considerable variability exists. Developmental changes, plausible disease-specific alterations and genetic polymorphisms in NTX disposition, and pharmacodynamic pathways should be taken into consideration when optimizing the use of NTX in the pediatric population. This review highlights the current state of the evidence and gaps in knowledge regarding NTX to facilitate evidence-based pharmacotherapy of mental health conditions, for which few pharmacologic options exist.

Screening for Unhealthy Drug Use: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Illicit drug use is among the most common causes of preventable morbidity and mortality in the US.

OBJECTIVE

To systematically review the literature on screening and interventions for drug use to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed, PsycINFO, Embase, and Cochrane Central Register of Controlled Trials through September 18, 2018; literature surveillance through September 21, 2019.

STUDY SELECTION

Test accuracy studies to detect drug misuse and randomized clinical trials of screening and interventions to reduce drug use.

DATA EXTRACTION AND SYNTHESIS

Critical appraisal and data abstraction by 2 reviewers and random-effects meta-analyses.

MAIN OUTCOMES AND MEASURES

Sensitivity, specificity, drug use and other health, social, and legal outcomes.

RESULTS

Ninety-nine studies (N = 84 206) were included. Twenty-eight studies (n = 65 720) addressed drug screening accuracy. Among adults, sensitivity and specificity of screening tools for detecting unhealthy drug use ranged from 0.71 to 0.94 and 0.87 to 0.97, respectively. Interventions to reduce drug use were evaluated in 52 trials (n = 15 659) of psychosocial interventions, 7 trials (n = 1109) of opioid agonist therapy, and 13 trials (n = 1718) of naltrexone. Psychosocial interventions were associated with increased likelihood of drug use abstinence (15 trials, n = 3636; relative risk [RR], 1.60 [95% CI, 1.24 to 2.13]; absolute risk difference [ARD], 9% [95% CI, 5% to 15%]) and reduced number of drug use days (19 trials, n = 5085; mean difference, -0.49 day in the last 7 days [95% CI, -0.85 to -0.13]) vs no psychosocial intervention at 3- to 4-month follow-up. In treatment-seeking populations, opioid agonist therapy and naltrexone were associated with decreased risk of drug use relapse (4 trials, n = 567; RR, 0.75 [95% CI, 0.59 to 0.82]; ARD, -35% [95% CI, -67% to -3%] and 12 trials, n = 1599; RR, 0.73 [95% CI, 0.62 to 0.85]; ARD, -18% [95% CI, -26% to -10%], respectively) vs placebo or no medication. While evidence on harms was limited, it indicated no increased risk of serious adverse events.

CONCLUSIONS AND RELEVANCE

Several screening instruments with acceptable sensitivity and specificity are available to screen for drug use, although there is no direct evidence on the benefits or harms of screening. Pharmacotherapy and psychosocial interventions are effective at improving drug use outcomes, but evidence of effectiveness remains primarily derived from trials conducted in treatment-seeking populations.

A call for consensus in defining efficacy in clinical trials for opioid addiction: combined results from a systematic review and qualitative study in patients receiving pharmacological assisted therapy for opioid use disorder

Background

Given the complex nature of opioid addiction treatment and the rising number of available opioid substitution and antagonist therapies (OSAT), there is no ‘gold standard’ measure of treatment effectiveness, and each successive trial measures a different set of outcomes which reflect success in arbitrary or opportune terms. We sought to describe the variation in current outcomes employed across clinical trials for opioid addiction, as well as determine whether a discrepancy exists between the treatment targets that patients consider important and how treatment effectiveness is measured in the literature.

Methods

We searched nine commonly used databases (e.g., EMBASE, MEDLINE) from inception to August 1, 2015. Outcomes used across trials were extracted and categorized according to previously established domains. To evaluate patient-reported goals of treatment, semi-structured interviews were conducted with 18 adults undergoing methadone treatment.

Results

We identified 60 trials eligible for inclusion. Once outcomes were categorized into eight broad domains (e.g., abstinence/substance abuse), we identified 21 specific outcomes with furthermore 53 subdomains and 118 measurements. Continued opioid use and treatment retention were the most commonly reported measures (46%, n = 28). The majority of patients agreed that abstinence from opioids was a primary goal in their treatment, although they also stressed goals under-reported in clinical trials.

Conclusions

There is inconsistency in the measures used to evaluate the effectiveness of OSATs. Individual and population level decision making is being guided by a standard of effect considered useful to researchers yet in direct conflict with what patients deem important.

Trial registration

PROSPERO, CRD42013006507.

Effect of ASF (a Compound of Traditional Chinese Medicine) on Behavioral Sensitization Induced by Ethanol and Conditioned Place Preference in Mice

ASF composed by semen and epimedium herbal is a traditional plant compound that is widely used in the treatment of insomnia. Studies have shown that saponins and flavonoids contained in semen can significantly decrease the content of excitatory neurotransmitter Glu in mice. And the total flavone of YinYangHuo can increase the release of GABA in the anterior periventricular system of rat and increase the affinity of GABA for the receptors GABAA. It can be inferred that their synergism may have effect on the neurotransmitter that causes behavioral sensitization and conditioned place preference in experimental animals and affects their drinking behaviors, which is the starting point of this research. The present study found that ASF can inhibit development and expression of behavioral sensitization induced by ethanol and the development of CPP in mice. We demonstrate the inhibition of ASF on behavioral sensitization partly due to its effect on the mesolimbic neurotransmitter system, including decreasing level of DA and Glu and increasing the content of GABA. It suggested that the ASF may have pharmacological effects in the treatment of alcohol addiction.

DSM IV axis II traits can influence compliance to treatment with oral naltrexone: a preliminary study on 30 opiate dependent patients

For many decades, health specialists have successfully used their clinical ingenuity to increase the efficiency of opiate detoxification protocols. However, even if drop-out rate has decreased significantly in today's protocols, relapse after opiate detoxification remains a major problem. Therefore, naltrexone hydrochloride, an opiate antagonist, has been considered by many as a potential tool to support abstinence in what has been called "antagonist-assisted abstinence" (AAA). Nevertheless, while naltrexone implants are becoming more accessible, a large majority of centers still use oral naltrexone and adherence to treatment remains a major obstacle to AAA's efficiency. As the personality profile could give an insight into compliance, we investigated the relationship between personality profiles and naltrexone adherence in a cohort of 30 patients. The results indicate that the Axis II profile influences the likely pattern of oral naltrexone compliance. As clinicians need to identify opiate dependent patients who are most likely to benefit from oral naltrexone treatment, it therefore carries important implications and could lead to a better adjustment of therapeutic strategies for opiate dependent patients.

Open label trial of naltrexone implants: measuring blood serum levels of naltrexone

The usefulness of oral naltrexone has been limited by compliance. Sub-cutaneous implants would seem to offer a solution to this problem and improve long-term outcomes. The aim of the present study was to compare levels of blood serum naltrexone of patients who had received a naltrexone implant after detoxification to a number of dependent variables of interest. These dependent variables included drug use including urine screens of each patient, any adverse response to the implant, subjective evaluation of self-esteem, quality of relationships, and changes in social functioning. Sixty six patients received an implant and were surveyed; urine and blood samples were taken at about 1, 3, and 6 months after implantation. Naltrexone levels were on average above 1 ng/mL at 6 months after insertion and patients showed significant improvements on all dependent variables. The preliminary evidence indicates that implants can improve compliance rates and outcomes.

Prediction of abstinence in opioid-dependent patients

OBJECTIVES

: Opioid detoxification with subsequent naltrexone is found to be an effective method as the first step in an abstinence-oriented approach. The aim of this study is to investigate the predictive value of variables for abstinence in opioid-dependent patients.

METHODS

: Opioid-dependent patients were followed up to 1 month after detoxification. Predictor variables were assessed at baseline, during detoxification, and at discharge. Primary outcome was abstinence assessed by analyzing urine samples and self-reports. Logistic regression was used to identify predictors of abstinence.

RESULTS

: Of 272 participants, 211 could be rated as abstinent (59.2%) or nonabstinent (40.8%) at 1 month follow-up. Significant baseline predictors were severity score of justice/police (ASI) and physical quality of life (SF-36); discharge predictors were general quality of health (SF-36) and sleeping problems (SCL-90); change in sleeping problems (SCL-90) during detoxification was also a predictor. The explained variance of these predictors was very low and clinical significance was limited.

CONCLUSIONS

: Considering the results it seems not possible to predict who will be abstinent or not 1 month after detoxification. Because rapid detoxification is found to be an effective detoxification method in selected patients, it seems warranted to recommend that patients with similar characteristics (ie, patients motivated for an abstinence-based treatment and low non-drug-related severity scores on the ASI) should be regarded as eligible for rapid detoxification.

Oral naltrexone maintenance treatment for opioid dependence

BACKGROUND

Research on clinical application of oral naltrexone agrees on several things. From a pharmacological perspective, naltrexone works. From an applied perspective, the medication compliance and the retention rates are poor.

OBJECTIVES

To evaluate the effects of naltrexone maintenance treatment versus placebo or other treatments in preventing relapse in opioid addicts after detoxification.

SEARCH STRATEGY

We searched: Cochrane Central Register of Controlled Trials (CENTRAL - The Cochrane Library issue 6 2010), PubMed (1973- June 2010), CINAHL (1982- June 2010). We inspected reference lists of relevant articles and contacted pharmaceutical producers of naltrexone, authors and other Cochrane review groups.

SELECTION CRITERIA

All randomised controlled clinical trials which focus on the use of naltrexone maintenance treatment versus placebo, or other treatments to reach sustained abstinence from opiate drugs

DATA COLLECTION AND ANALYSIS

Three reviewers independently assessed studies for inclusion and extracted data. One reviewer carried out the qualitative assessments of the methodology of eligible studies using validated checklists.

MAIN RESULTS

Thirteen studies, 1158 participants, met the criteria for inclusion in this review.Comparing naltrexone versus placebo or no pharmacological treatments, no statistically significant difference were noted for all the primary outcomes considered. The only outcome statistically significant in favour of naltrexone is re incarceration, RR 0.47 (95%CI 0.26-0.84), but results come only from two studies. Considering only studies were patients were forced to adherence a statistical significant difference in favour of naltrexone was found for retention and abstinence, RR 2.93 (95%CI 1.66-5.18).Comparing naltrexone versus psychotherapy, in the two considered outcomes, no statistically significant difference was found in the single study considered.Naltrexone was not superior to benzodiazepines and to buprenorphine for retention and abstinence and side effects. Results come from single studies.

AUTHORS' CONCLUSIONS

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.

Oral naltrexone maintenance treatment for opioid dependence

BACKGROUND

Research on the clinical application of oral naltrexone agrees on several things. From a pharmacological perspective, naltrexone works. From an applied perspective, however, the medication compliance and the retention rates are very poor.

OBJECTIVES

To evaluate the effects of naltrexone maintenance treatment versus placebo or other treatments in preventing relapse in opioid addicts after detoxification.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL - The Cochrane Library issue 6 2010), PubMed (1973- June 2010), CINAHL (1982- June 2010). We inspected reference lists of relevant articles and we contacted pharmaceutical producers of naltrexone, authors and other Cochrane review groups.

SELECTION CRITERIA

All randomised and controlled clinical trials which focus on the use of naltrexone maintenance treatment versus placebo, or other treatments to reach sustained abstinence from opiate drugs

DATA COLLECTION AND ANALYSIS

Three reviewers independently assessed studies for inclusion and extracted data. One reviewer carried out the qualitative assessments of the methodology of eligible studies using validated checklists.

MAIN RESULTS

Thirteen studies, 1158 participants, met the criteria for inclusion in this review.Comparing naltrexone versus placebo or no pharmacological treatments, no statistically significant difference were noted for all the primary outcomes considered. The only outcome statistically significant in favour of naltrexone is re incarceration, RR 0.47 (95%CI 0.26-0.84), but results come only from two studies.Comparing naltrexone versus psychotherapy, in the two considered outcomes, no statistically significant difference was found in the single study considered.Naltrexone was not superior to benzodiazepines and to buprenorphine for retention and abstinence and side effects. Results come from single studies.

AUTHORS' CONCLUSIONS

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.

Long-acting injectable naltrexone for the management of patients with opioid dependence

Opioid dependence is a condition with serious clinical ramifications. Treatment has focused on detoxification, agonist therapy with methadone or buprenorphine, or remission maintenance with the opioid antagonist, naltrexone. Treatment with oral naltrexone has been limited by poor treatment adherence and relapse. Studies with long-acting formulations have shown increased treatment adherence. Extended-release injectable naltrexone has been used for the treatment of alcohol dependence, and has recently received an indication for treatment of opioid dependence from the US Food and Drug Administration. Dosing occurs once monthly and existing data with long-acting naltrexone supports efficacy of treatment for opioid dependence; however published data is sparse. Treatment with long-acting naltrexone should be monitored for hepatotoxicity, and patients should be made aware of increased risk of overdose with administration of opioids during and immediately after discontinuation of long-acting naltrexone.

A randomized trial of oral naltrexone for treating opioid-dependent offenders

Offenders with a history of opioid dependence are a particularly difficult group to treat. A large proportion of offenders typically relapse shortly after release from prison, commit drug-related crimes, and then are arrested and eventually re-incarcerated. Previous research demonstrated that oral naltrexone was effective in reducing opioid use and preventing recidivism among offenders under federal supervision. The 111 opioid-dependent offenders in this study were under various levels of supervision that included county and federal probation/parole, a treatment court, an alternative disposition program, and an intermediate punishment program. Subjects were randomly assigned to receive 6 months of either 300 mg per week of oral naltrexone plus standard psychosocial treatment as usual (n = 56) or standard psychosocial treatment as usual (TAU) without naltrexone (n = 55). While the TAU subjects who remained in treatment used more opioids than the naltrexone subjects who remained, the high dropout rate for both groups made it difficult to assess the effectiveness of naltrexone. The study provides limited support for the use of oral naltrexone for offenders who are not closely monitored by the criminal justice system.

The pharmacological treatment of opioid addiction--a clinical perspective

This article reviews the main pharmacotherapies that are currently being used to treat opioid addiction. Treatments include detoxification using tapered methadone, buprenorphine, adrenergic agonists such as clonidine and lofexidine, and forms of rapid detoxification. In opioid maintenance treatment (OMT), methadone is most widely used. OMT with buprenorphine, buprenorphine-naloxone combination, or other opioid agonists is also discussed. The use of the opioid antagonists naloxone (for the treatment of intoxication and overdose) and oral and sustained-release formulations of naltrexone (for relapse prevention) is also considered. Although recent advances in the neurobiology of addictions may lead to the development of new pharmacotherapies for the treatment of addictive disorders, a major challenge lies in delivering existing treatments more effectively. Pharmacotherapy of opioid addiction alone is usually insufficient, and a complete treatment should also include effective psychosocial support or other interventions. Combining pharmacotherapies with psychosocial support strategies that are tailored to meet the patients' needs represents the best way to treat opioid addiction effectively.

Naltrexone maintenance for heroin dependence: uptake, attrition and retention

With naltrexone registered only recently in Australia in 1999, it is important to examine the rate of uptake of naltrexone treatment, early attrition and retention rates during treatment, in order to inform the way naltrexone is used in Australian practice. Of 317 people screened for the study, 97 participants were recruited post-withdrawal from opiates and were inducted to naltrexone after a period of at least 5 days of abstinence. While in treatment, participants received a 50-mg dose of naltrexone daily, with daily dispensing for the first 7 days, and weekly dispensing for the following 11 weeks. For the naltrexone-treated sample as a whole, the rate of uptake of naltrexone treatment was 30%, with 30% retained in treatment for the entire 12-week program. Attrition from treatment was found to be steady throughout the 12 weeks. The authors conclude that further research is required to improve withdrawal and naltrexone induction techniques and to improve medication compliance and treatment retention.

Effectiveness of low-dose naltrexone in the post-detoxification treatment of opioid dependence

BACKGROUND

The clinical use of naltrexone (NTX) in the treatment of opioid dependence has been limited because of poor compliance and inconsistent outcomes. In particular, the therapeutic benefit of extended treatment with NTX after opioid detoxification is unclear. The present study evaluated whether the augmentation with low-dose NTX during the post-detoxification treatment of opioid dependence would improve outcomes.

METHODS

In an open-label naturalistic design, 435 opioid-dependent patients who had completed inpatient detoxification were offered the choice of entering 1 of the 2 outpatient treatment arms: clonidine extended treatment (CET) (clonidine + psychosocial treatment), or enhanced extended treatment (EET) (oral NTX [1-10 mg/d] + CET) for 21 days. The primary outcome measure was retention in treatment. Secondary outcomes included abstinence from opioids, dropouts, and adherence to postdischarge care.

RESULTS

One hundred sixty-two patients (37.2%) accepted EET. Subjects receiving EET stayed longer in the program (F = 64.4; P = 0.000), were less likely to drop out, used less opioids, and followed through with referral to long-term outpatient treatment in a higher number, compared with patients in the CET arm (P = 0.000 in each case). The NTX + clonidine combination was safe and well tolerated.

CONCLUSIONS

This preliminary study indicates the potential benefit of augmentation with low-dose NTX to improve outcomes after opioid detoxification for a preferred group of patients. Randomized controlled trials are necessary to further evaluate the role of low-dose NTX in the outpatient treatment of opioid dependence.

Toward a model of drug relapse: an assessment of the validity of the reinstatement procedure

BACKGROUND AND RATIONALE

The reinstatement model is widely used to study relapse to drug addiction. However, the model's validity is open to question.

OBJECTIVE

We assess the reinstatement model in terms of criterion and construct validity.

RESEARCH HIGHLIGHTS AND CONCLUSIONS

We find that the reinstatement model has adequate criterion validity in the broad sense of the term, as evidenced by the fact that reinstatement in laboratory animals is induced by conditions reported to provoke relapse in humans. The model's criterion validity in the narrower sense, as a medication screen, seems promising for relapse to heroin, nicotine, and alcohol. For relapse to cocaine, criterion validity has not yet been established primarily because clinical studies have examined medication's effects on reductions in cocaine intake rather than relapse during abstinence. The model's construct validity faces more substantial challenges and is yet to be established, but we argue that some of the criticisms of the model in this regard may have been overstated.

Food intake and reward mechanisms in patients with schizophrenia: implications for metabolic disturbances and treatment with second-generation antipsychotic agents

Obesity is highly prevalent among patients with schizophrenia and is associated with detrimental health consequences. Although excessive consumption of fast food and pharmacotherapy with such second-generation antipsychotic agents (SGAs) as clozapine and olanzapine has been implicated in the schizophrenia/obesity comorbidity, the pathophysiology of this link remains unclear. Here, we propose a mechanism based on brain reward function, a relevant etiologic factor in both schizophrenia and overeating. A comprehensive literature search on neurobiology of schizophrenia and of eating behavior was performed. The collected articles were critically reviewed and relevant data were extracted and summarized within four key areas: (1) energy homeostasis, (2) food reward and hedonics, (3) reward function in schizophrenia, and (4) metabolic effects of the SGAs. A mesolimbic hyperdopaminergic state may render motivational/incentive reward system insensitive to low salience/palatability food. This, together with poor cognitive control from hypofunctional prefrontal cortex and enhanced hedonic impact of food, owing to exaggerated opioidergic drive (clinically manifested as pain insensitivity), may underlie unhealthy eating habits in patients with schizophrenia. Treatment with SGAs purportedly improves dopamine-mediated reward aspects, but at the cost of increased appetite and worsened or at least not improved opiodergic capacity. These effects can further deteriorate eating patterns. Pathophysiological and therapeutic implications of these insights need further validation via prospective clinical trials and neuroimaging studies.

Evidenced-based treatment of opioid-dependent patients

OBJECTIVE

To provide an overview of treatment options for opioid-dependent patients.

METHOD

We screened all published studies on the treatment of opioid dependence, with a special focus on systematic literature reviews, formal metaanalyses, and recent trials.

RESULTS

Both clinical experience and neurobiological evidence indicate that opioid dependence is a chronic relapsing disorder. Treatment objectives depend on the pursued goals: crisis intervention, abstinence-oriented treatment (detoxification and relapse prevention), or agonist maintenance treatment. The high quality of solid evidence in the literature demonstrates that there are numerous effective interventions available for the treatment of opioid dependence. Crisis intervention, frequently necessary owing to the high overdose rate, can be effectively handled with naloxone. Abstinence-oriented interventions are effective for only a few motivated patients with stable living conditions and adequate social support. Agonist maintenance treatment is considered the first line of treatment for opioid dependence. Numerous studies have shown efficacy for methadone and buprenorphine treatment, while maintenance with other agonists is also becoming available to a greater extent. Maintenance treatment with diamorphine should be made available for the small group of treatment-resistant, severely dependent addicts. Other harm-reduction measures can serve to engage individuals with opioid addiction who are not in treatment.

CONCLUSION

Opioid dependence is a chronic relapsing disease that is difficult to cure, but effective treatments are available to stabilize patients and reduce harm, thereby increasing life expectancy and quality of life.

A systematic review of the effectiveness of naltrexone in the maintenance treatment of opioid and alcohol dependence

This systematic review summarises evidence of the effectiveness of naltrexone (NTX) and the added value of psychosocial treatment in the maintenance treatment of opioid and alcohol dependence. Studies were selected through a literature search conducted in March 2004. Seven opioid and seventeen alcohol studies were identified. When possible, meta-(regression) analyses were performed. There is lack of evidence about the effectiveness of NTX in the maintenance treatment of opioid dependence. There is evidence for the effectiveness and applicability of NTX in the management of alcohol dependence. The opioid studies combined NTX with a variety of psychosocial interventions, which plagued the evaluation of their value. Concomitant psychosocial interventions used in the alcohol studies were mainly cognitive behavioural, which seems to be more effective than NTX combined with supportive therapy. Available data do not allow firm conclusions regarding the added effect of psychosocial interventions. However, the data suggest that a combination of naltrexone with cognitive behavioural relapse prevention therapy is beneficial in alcohol dependent patients.

Efficacy of maintenance treatment with naltrexone for opioid dependence: a meta-analytical review

AIMS

To determine the efficacy of naltrexone in reducing illicit opioid use and the potential moderating role of treatment retention.

DESIGN

First, randomized controlled trials (RCTs) comparing the regimens of treatment using the opioid antagonist, naltrexone, with controls were analysed by meta-analysis for treatment effect with regard to a range of outcome criteria. The degree of heterogeneity was also determined. The moderating effect of other interventions during naltrexone maintenance was then estimated, particularly with regard to their effect on treatment retention.

PARTICIPANTS

Fifteen studies involving 1,071 patients were found.

MEASUREMENTS

All available outcomes were analysed in 10 studies of naltrexone versus control (seven placebo) and six studies of randomized psychosocial/psychopharmacological interventions.

FINDINGS

Significant heterogeneity was found in the efficacy of naltrexone. Level of retention in treatment was found to be a moderator, explaining most of the heterogeneity found. Overall, naltrexone was significantly better than control conditions in reducing the number of opioid-positive urines. This effect was only present in the high retention subgroup for differences in retention. Contingency management (CM) increased retention and naltrexone use, resulting in a reduced number of opioid-positive urines.

CONCLUSION

Retention is important to the effect of naltrexone in treating opioid dependence. Contingency management is a promising method of increasing retention.

Oral naltrexone maintenance treatment for opioid dependence

BACKGROUND

Research on the clinical application of oral naltrexone agrees on several things. From a pharmacological perspective, naltrexone works. From an applied perspective, however, this medication is not used since the medication compliance and the retention rates are very poor.

OBJECTIVES

To evaluate the effects of naltrexone maintenance treatment versus placebo or other treatments in preventing relapse in opioid addicts after detoxification.

SEARCH STRATEGY

We searched the Cochrane Drugs and Alcohol Group Register of Trials (January 2005), Cochrane Central Register of Controlled Trials (CENTRAL - The Cochrane Library Issue 1, 2005), MEDLINE (1973-first year of naltrexone use in humans- January 2005), EMBASE (1974- January 2005), PsycINFO (OVID-January 1985 to January 2004). We inspected reference lists of relevant articles and we contacted pharmaceutical producers of naltrexone, authors and other Cochrane review groups.

SELECTION CRITERIA

All randomised and controlled clinical trials which focus on the use of naltrexone maintenance treatment versus placebo, or other treatments to reach sustained abstinence from opiate drugs

DATA COLLECTION AND ANALYSIS

Three reviewers independently assessed studies for inclusion and extracted data. One reviewer carried out the qualitative assessments of the methodology of eligible studies using validated checklists.

MAIN RESULTS

Ten studies, 696 participants, met the criteria for inclusion in this review. Only two studies described an adequate allocation concealment. The results show that naltrexone maintenance therapy alone or associated with psychosocial therapy is more efficacious that placebo alone or associated with psychosocial therapy in limiting the use of heroin during the treatment (RR 0,72 95% confidence interval 0.58 to 0.90). If we consider only the studies comparing naltrexone with placebo, the difference do not reach the statistical significancy, RR 0.79 (95%CI 0.59 to 1.06). With respect to the number of participants re incarcerated during the study period, the naltrexone associated with psychosocial therapy is more effective than the psychosocial treatment alone; RR 0.50 (95%CI 0.27 to 0.91). No statistically significant benefit was shown in terms of retention in treatment, side effects or relapse results at follow-up for any of the considered comparisons.

AUTHORS' CONCLUSIONS

Unfortunately the studies did not provide an objective evaluation of naltrexone treatment in the field of opioid dependence. The conclusions are also limited due to the heterogeneity of the trials both in the interventions and in the assessment of outcomes.

Combating opiate dependence: a comparison among the available pharmacological options

Pharmacotherapies for heroin addiction may target opiate withdrawal symptoms, facilitate initiation of abstinence and/or reduce relapse to heroin use either by maintenance on an agonist or antagonist agent. Available agents include opioid agonists, partial opioid agonists, opioid antagonists and alpha 2 -agonists for use during managed withdrawal and long-term maintenance. Experimental approaches combine alpha 2 -agonists with naltrexone to reduce the time of opiate withdrawal and to accelerate the transition to abstinence. Recently, buprenorphine has been introduced in the US for office-based maintenance, with the hope of replicating the success of this treatment in Europe and Australia. Naloxone has been added to buprenorphine in order to reduce its potential diversion to intravenous use, whilst facilitating the expansion of treatment. Although comprehensive substance abuse treatment is not limited to pharmacotherapy, this review will focus on the rationale, indications and limitations of the range of existing medications for detoxification and relapse prevention treatments. The two major goals of pharmacotherapy are to relieve the severity of opiate withdrawal symptoms during the managed withdrawal of the opioid and to prevent relapse to heroin use either after abstinence initiation or after being stabilised on a long-acting opiate agonist, such as methadone.

Narcotic antagonists in drug dependence: pilot study showing enhancement of compliance with SYN-10, amino-acid precursors and enkephalinase inhibition therapy

We decided to test the hypothesis that possibly by combining a narcotic antagonist and amino-acid therapy consisting of an enkephalinase inhibitor (D-phenylalanine) and neurotransmitter precursors (L-amino- acids) to promote neuronal dopamine release might enhance compliance in methadone patients rapidly detoxified with the narcotic antagonist Trexan (Dupont, Delaware). In this regard, Thanos et al. [J. Neurochem. 78 (2001) 1094] and associates found increases in the dopamine D2 receptors (DRD2) via adenoviral vector delivery of the DRD2 gene into the nucleus accumbens, significantly reduced both ethanol preference (43%) and alcohol intake (64%) of ethanol preferring rats, which recovered as the DRD2, returned to baseline levels. This DRD2 overexpression similarly produced significant reductions in ethanol non-preferring rats, in both alcohol preference (16%) and alcohol intake (75%). This work further suggests that high levels of DRD2 may be protective against alcohol abuse [JAMA 263 (1990) 2055; Arch, Gen. Psychiatr. 48 (1991) 648]. The DRD2 A1 allele has also been shown to associate with heroin addicts in a number of studies. In addition, other dopaminergic receptor gene polymorphisms have also associated with opioid dependence. For example, Kotler et al. [Mol. Phychiatr. 3 (1997) 251] showed that the 7 repeat allele of the DRD4 receptor is significantly overpresented in the opioid-dependent cohort and confers a relative risk of 2.46. This has been confirmed by Li et al. [Mol. Psychiatry 2 (1997) 413] for both the 5 and 7 repeat alleles in Han Chinese case control sample of heroin addicts. Similarly Duaux et al. [Mol. Psychiatry 3 (1998) 333] in French Heroin addicts, found a significant association with homozygotes alleles of the DRD3-Bal 1. A study from NIAAA, provided evidence which strongly suggests that DRD2 is a susceptibility gene for substance abusers across multiple populations (2003). Moreover, there are a number of studies utilizing amino-acid and enkephalinase inhibition therapy showing reduction of alcohol, opiate, cocaine and sugar craving behavior in human trials (see Table 1). Over the last decade, a new rapid method to detoxify either methadone or heroin addicts utilizing Trexan sparked interest in many treatment centers throughout the United States, Canada, as well as many countries on a worldwide basis. In using the combination of Trexan and amino-acids, results were dramatic in terms of significantly enhancing compliance to continue taking Trexan. The average number of days of compliance calculated on 1000 patients, without amino-acid therapy, using this rapid detoxification method is only 37 days. In contrast, the 12 subjects tested, receiving both the Trexan and amino-acid therapy was relapse-free or reported taking the combination for an average of 262 days (p < 0.0001F). Thus coupling amino-acid therapy and enkephalinase inhibition while blocking the delta-receptors with a pure narcotic antagonist may be quite promising as a novel method to induce rapid detox in chronic methadone patients. This may also have important ramifications in the treatment of both opiate and alcohol-dependent individuals, especially as a relapse prevention tool. It may also be interesting too further test this hypothesis with the sublingual combination of the partial opiate mu receptor agonist buprenorphrine.

Pharmacological treatments for heroin and cocaine addiction

AIMS

To provide an overview of the pharmacological options for the treatment of heroin- and cocaine-dependent patients based on known biochemical pathways to addiction and the chronic disease model as a starting point for treatment planning.

RESULTS

Recent pre-clinical and clinical studies indicate that different brain structures and different neurotransmitters are involved in different stages of the addiction process. In addition, clinical experience shows that heroin and cocaine addiction can best be conceptualised and treated as a chronic, relapsing disorder with the following treatment goals: crisis intervention, cure or recovery (detoxification, relapse prevention) and care or partial remission (stabilization and harm reduction). The various high-quality studies, systematic literature reviews and formal meta-analyses clearly demonstrate that today many proven effective interventions are available for crisis intervention, detoxification, stabilization and harm reduction for heroin-dependent patients. Interventions directed at relapse prevention are still problematic and only effective in a minority of motivated patients in stable living conditions and adequate social support. In contrast, no proven effective pharmacological interventions are available for the treatment of cocaine-dependent patients, maybe with the exception of some patient groups that seem to benefit from treatment with disulfiram or amantadine. Treatment innovations are primarily based on experimental animal studies. Newly developed cannabinoid receptor antagonists and cortisol synthesis inhibitors show great promise.

CONCLUSION

Heroin addiction is a chronic relapsing disease that is difficult to cure, but stabilization and harm reduction can greatly increase the life time expectancy and the quality of life of the patient, his direct environment and society as a whole. Currently, no proven effective pharmacological interventions are available for cocaine addiction, and treatment has to rely on existing cognitive behaviour therapies combined with contingency management strategies.

A systematic review on the efficacy of naltrexone maintenance treatment in opioid dependence

AIM

To evaluate the efficacy of naltrexone maintenance treatment in preventing relapse in opioid addicts after detoxification.

DESIGN

A systematic review according to the methodology developed by the Cochrane Collaboration based on either randomized controlled trials (RCTs) or controlled clinical trials (CCTs).

PARTICIPANTS

Seven hundred and seven heroin dependent in- and out-patients, or former heroin addicts dependent on methadone and participating in a naltrexone treatment programme; 89% were male.

INTERVENTION

Maintenance treatments on opiate dependent people after detoxification, comparing naltrexone with placebo, pharmacological or behavioural treatments.

MEASUREMENTS

The outcomes considered were successfully completed treatment, opioid use under treatment (re)-incarcerations during the study period, mean duration of treatment.

FINDINGS

The outcomes tended to be slightly although not significantly in favour of the naltrexone groups. Use of naltrexone in addition to behavioural treatment significantly decreased the probability of (re-)incarceration (OR=0.30; 95% CI 0.12, 0.76). The difficulties in producing a quantitative analysis were due mainly to the heterogeneity of the included studies.

CONCLUSIONS

From the available clinical trials performed up to this time, there is insufficient evidence to justify the use of naltrexone in maintenance treatment of opioid addicts.

Treatment of heroin (diamorphine) addiction: current approaches and future prospects

New pharmacological treatments for heroin (diamorphine) addiction include drugs that reduce opiate withdrawal symptoms and agents that are given during the maintenance phase of treatment. A variety of different types of pharmacological agents (opioid agonists, partial opioid agonists, opioid antagonists and alpha(2)-adrenoreceptor agonists) are reviewed and the evidence of their use during managed withdrawal and maintenance are presented. Experimental approaches attempting to reduce the time of opiate withdrawal and to accelerate the transition to abstinence are being developed. The combination tablet of buprenorphine and naloxone that is to be introduced for office-based maintenance is currently undergoing intense evaluation in the US. This new approach may facilitate the expansion of treatment while reducing the potential for medication diversion and intravenous use.

Naltrexone in the treatment of heroin dependence: relationship with depression and risk of overdose

OBJECTIVE

This article examines the use of naltrexone in the treatment of heroin dependence. The relationship between naltrexone and depression as well as risk of overdose is examined.

METHOD

The existing literature is reviewed along with recent interim data from clinical trials underway in Victoria.

RESULTS

Naltrexone is a recent addition to treatment for heroin dependence in Australia. The relationship between depression and naltrexone has been examined in previous literature. Underlying rates of depression in heroin users are high and treatment may resolve or exacerbate depression. Research to date demonstrates that the addition of naltrexone does not necessarily increase depression in patients. The risk of non-fatal heroin overdose is significantly elevated after naltrexone treatment as a result of reduced tolerance. Data from clinical trials underway in Victoria demonstrate a significantly elevated rate of non-fatal overdose in naltrexone patients compared to those in substitution maintenance treatment. The mortality rate subsequent to naltrexone treatment appears to be equivalent to or greater than that for untreated heroin users. Further research is required.

CONCLUSIONS

Clinicians need to carefully monitor depression in patients, and warn patients of the risks of reduced tolerance to opiates following naltrexone treatment. Agonist treatments such as methadone, LAAM and buprenorphine carry much less risk of overdose.

Depot naltrexone: long-lasting antagonism of the effects of heroin in humans

RATIONALE

Naltrexone, an opioid antagonist, is currently approved as a treatment for heroin dependence. However, naltrexone is generally not well accepted by patients, and medication non-compliance is a difficult obstacle to treatment. A sustained-release form of naltrexone may improve compliance.

OBJECTIVE

The present study was designed to evaluate the time course, safety, and effectiveness of a depot formulation of naltrexone (Depotrex).

METHODS

Twelve heroin-dependent individuals participated in an 8-week inpatient study. After a 1-week detoxification period, six participants received 192 mg naltrexone base and six participants received 384 mg naltrexone base. For safety, the low dose of depot naltrexone was tested before the high dose. The effects of heroin (0, 6.25, 12.5, 18.75, 25 mg, i.v.) were evaluated for the next 6 weeks. One dose of heroin was tested per day on Mondays through Fridays, and the entire dose range was tested each week. Active heroin doses were administered in ascending order during the week, while placebo could be administered on any day. Subjective, performance, and physiological effects were measured both before and after heroin administration. The hypotheses were that depot naltrexone would antagonize the effects of heroin, and that the high dose of depot naltrexone would produce a more effective and longer-lasting antagonism than the low dose.

RESULTS

The low and high doses of depot naltrexone antagonized heroin-induced subjective ratings for 3 and 5 weeks, respectively. Plasma levels of naltrexone remained above 1 ng/ml for approximately 3 and 4 weeks after administration of 192 mg and 384 mg naltrexone. Other than the initial discomfort associated with the injection of depot naltrexone, there were no untoward side-effects.

CONCLUSIONS

These results suggest that this depot formulation of naltrexone provides a safe, effective, long-lasting antagonism of the effects of heroin.

Naltrexone maintenance treatment for opioid dependence

BACKGROUND

Despite widespread use of naltrexone maintenance in many countries for more than a decade, the evidence of its effects has not yet been systematically evaluated.

OBJECTIVES

To evaluate the effects of naltrexone maintenance treatment in preventing relapse in opioid addicts after detoxification.

SEARCH STRATEGY

We searched MEDLINE (1973-first year of naltrexone use in humans-July 2000), EMBASE (1974-July 2000), Cochrane Controlled Trials Register (Cochrane Library issue 2001.4) and handsearched the "Bolletino per le Farmacodipendenze e l'Alcolismo" (1978 to 1997) and reference lists of relevant articles. We contacted pharmaceutical producers of naltrexone, authors and other Cochrane review groups. Date of most recent searches: December 2001.

SELECTION CRITERIA

All controlled studies of naltrexone; treatment of heroin addicts after detoxification.

DATA COLLECTION AND ANALYSIS

Reviewers evaluated data independently and analysed outcome measures taking into consideration adherence to and success of the study intervention. Data were extracted and analysed stratifying for the three categories of study quality. Where possible, meta-analysis was performed.

MAIN RESULTS

Eleven studies met the criteria for inclusion in this review, even if not all of them were randomised. The methodological quality of the included studies varied, but was generally poor. Meta-analysis could be performed to a very low degree only, because the studies and their outcome measures were very heterogeneous. A statistically significant reduction of (re-)incarcerations was found for patients treated with naltrexone and behaviour therapy in respect to those treated with behaviour therapy only. The other outcomes considered in the meta-analysis did not yield any significant results. Final conclusions on whether naltrexone treatment may be considered effective in maintenance therapy cannot be drawn from the clinical trials available so far.

REVIEWER'S CONCLUSIONS

The available trials do not allow a final evaluation of naltrexone maintenance treatment yet. A trend in favour of treatment with naltrexone was observed for certain target groups (particularly people who are highly motivated), as has been previously described in the literature.

Effect of nonnicotine pharmacotherapy on smoking behavior

Smoking-related disease is the single biggest preventable cause of morbidity and mortality in the United States, yet approximately 25% of Americans continue to smoke. Various dosage forms of nicotine replacement therapy increase smoking quit rates relative to placebo, but they generally do not result in 1-year quit rates of over 20%. To increase these rates, a number of nonnicotine agents have been investigated. Drugs that modulate noradrenergic neurotransmission (bupropion, nortriptyline, moclobemide) are more effective than those affecting serotonin (selective serotonin reuptake inhibitors, buspirone, ondansetron) or other neurotransmitters.

The impact of naloxone/lofexidine combination treatment on the opiate withdrawal syndrome

Clinical studies in opiate-dependent patients suggest that detoxification treatment with opiate antagonists may accelerate the resolution of the opiate withdrawal syndrome, permitting early induction onto naltrexone maintenance treatment. The present open study compared the clinical efficacy of daily naloxone injections in conjunction with lofexidine, with conventional lofexidine monotherapy, in 49 polysubstance-misusing opiate-dependent patients. Overall, the addition of naloxone did not confer substantial benefit over lofexidine monotherapy, although area-under-the-curve analysis showed that withdrawal severity in the naloxone/lofexidine combination group was significantly less than in the lofexidine monotherapy group, who experienced more severe withdrawal symptoms on days 4, 7, 9 and 13 of treatment. There were no significant differences in rates of completion of detoxification. Blood pressure remained within normal limits in both groups. Naltrexone maintenance treatment acceptability was low; only four patients continued with treatment for 5 or more days. The modest benefit of adding naloxone to lofexidine compared to the findings of previous opiate antagonist detoxification treatment studies is discussed in the context of the hypothesis that a critical level of opiate receptor occupancy is required to accelerate resolution of opiate withdrawal; the neurochemical mechanisms which may promote this are discussed.

Ultra rapid opiate detoxification as compared to 30-day inpatient detoxification program--a retrospective follow-up study

PURPOSE

Ultra rapid detoxification (URD) has recently gained significant media attention as a promising treatment for opiate addiction. URD combined with follow-up naltrexone was portrayed as a quick and painless initial detoxification, as well as a long-term cure for the addiction. Following the therapeutic initiation of URD, articles began to emerge in the scientific literature. URD was skeptically viewed by the substance addiction treatment community, skepticism initially based on the theoretical understanding of addiction as a bio-psycho-social problem and the belief that detoxification and medication alone cannot provide long-term abstinence. This initial response was later supported by some scientific studies. URD continues to stir controversy, leading to this study.

METHODS

We used available data to conduct a pilot study of URD, comparing it to traditional 30-day inpatient detoxification programs (IDP) used in Israel in achieving long-term abstinence. A sample of 226 men and women, 18 years or older, who entered detoxification in the IDP (N = 87) or in the URD (N = 139) were all clients who received treatment in either of these programs between March and September 1996. Eighty-one (92%) of the IDP subjects and eighty-two (60%) of the URD subjects were successfully interviewed by telephone 12 to 18 months after their participation in these programs.

RESULTS

The results provide preliminary evidence that URD may be much less effective and more expensive than traditional treatment. No specific subgroup of clients benefited more from URD, although a prospective study employing random assignment might be more successful in identifying such a group.

IMPLICATIONS

This study appears to offer justification for the current longer-term bio-psycho-social treatment alternatives for opiate addiction.

Ultrarapid opioid detoxification: effects on cardiopulmonary physiology, stress hormones and clinical outcomes

This study explored the acute and long-term consequences of ultrarapid opioid detoxification (URD) in individuals with opioid dependence. In an open case series, seven patients underwent URD and subsequent treatment with daily naltrexone. Structured interviews, integrated rehabilitation and hair sampling were employed in the 12-week course of longitudinal follow-up. Cardiac and pulmonary physiology did not change significantly during the anesthesia phase of URD, but plasma ACTH and cortisol levels increased 15- and 13-fold, respectively. Marked withdrawal and tachypnea in all patients and respiratory distress in one patient occurred during the acute post-anesthesia phase. Withdrawal scores were significantly elevated for 3 weeks compared with baseline in the face of minimal self-reported craving for opioids. Anxiety, depression and vegetative symptoms improved gradually. Four patients remained abstinent of opioid use, two reported a brief period of opioid intake and one relapsed into daily opioid consumption. Given its effect on breathing and stress hormones, this procedure should be conducted by experienced anesthesiologists. The fact that URD and subsequent naltrexone treatment appears to cause a dissociation effect in the usual relationship between withdrawal and craving has implications for behavioral pharmacology. Further research is needed on the efficacy, safety, mechanisms and neurobiological sequelae of the procedure.

Heroin use among adolescents in treatment for substance use disorders

OBJECTIVE

To clarify prevalence rates and describe patterns of adolescent heroin users who are in treatment for substance use disorders.

METHOD

The Treatment Episode Data Set (TEDS) was examined for trends in the number of adolescents admitted to substance abuse treatment centers and for changes in the routes of heroin administration. Thirteen adolescents who used heroin from one treatment program were compared with 536 adolescents who did not.

RESULTS

Between 1992 and 1996, heroin-using youths represented 2.0% of youths in treatment and in 1997 they represented 2.6%. Heroin-using youths represented 56% of those using injection drugs. Heroin-using youths from one treatment program had significantly more polysubstance dependence in comparison with adolescents who did not use heroin.

CONCLUSIONS

Nationally, there has been an increasing number, but not percentage, of heroin-using youths in treatment between 1992 and 1996. In 1997 there was an increase in both the number and percentage of heroin-using youths in treatment. Heroin-using adolescents have the highest rate of injection drug use when compared with youths using other substances. Because of their greater risk of contracting human immunodeficiency virus through injection drug use, treatment trials for these adolescents are needed.

A method of reducing the opioid withdrawal intensity using progressively increasing doses of naloxone

We assessed the withdrawal intensity in acutely morphine-dependent mice using a pretreatment with escalating doses of naloxone. All animals received a single dose of morphine (100 mg/kg) for the induction of acute opioid dependency. Group 1 (control) received three injections of normal saline and then naloxone 0.8 mg/kg. Group 2 received increasing pretreatment doses of naloxone (0.1, 0.2, and 0.4 mg/kg) and a challenge dose of 0.8 mg/kg. Group 3 received three injections of naloxone 0.1 mg/kg and a challenge dose of 0.8 mg/kg. Groups 4 and 5 were used to verify whether ED(50) found in previous studies was comparable with values obtained in the current experiments. The withdrawal intensity was determined by the number of jumps. The mice of group 1 exhibited significantly more jumps after 0.8 mg/kg of naloxone as compared with group 2. The number of jumps in response to naloxone between groups 1 and 2 and groups 2 and 3 was not significantly different. The results show that pretreatment with increasing naloxone doses significantly reduced the withdrawal intensity as compared with the control group; whereas pretreatment with repeated low antagonist did not reduce it significantly.

Naltrexone shortened opioid detoxification with buprenorphine

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.