Intramuscular extended-release naltrexone: current evidence

Attitudes toward extended-release naltrexone treatment for opioid use disorder among African Americans

BACKGROUND

Extended-release naltrexone (XR-NTX; Vivitrol®) is a long-acting injectable form of naltrexone, which is a medication used to treat opioid use disorder (OUD). In 2010, XR-NTX received Food and Drug Administration approval to treat OUD, becoming the first non-addictive and non-psychoactive medication for this condition. Because uptake of XR-NTX has been relatively low, less is known regarding how persons with OUD view this form of treatment. And because previous studies tend to rely on samples that lack racial diversity or are conducted outside the United States, we know very little about how African Americans view XR-NTX. The objective of this study, therefore, was to identify/explain the most salient attitudes toward XR-NTX as a form of OUD treatment among African Americans.

METHODS

In-depth interviews (n = 30) were conducted with a sample of African American adults who used opioids in Southwest Florida between August 2021 and February 2022. Audiotapes of interviews were transcribed, coded, and thematically analyzed.

RESULTS

Analyses revealed that participants' attitudes toward XR-NTX were generally positive. Specifically, participants found XR-NTX's monthly injection administration, non-addictive and non-intoxicating properties, and perceived effectiveness (compared to other medications for OUD) most appealing.

CONCLUSIONS

Study findings suggest that African Americans who use opioids may have more favorable attitudes toward XR-NTX than other medications for OUD (e.g., methadone), which tend to be highly stigmatized. These data uniquely contribute to the literature by capturing the voices of African Americans who use opioids, a group with high rates of opioid-related deaths.

Machine-learning analysis of opioid use disorder informed by MOR, DOR, KOR, NOR and ZOR-based interactome networks

Opioid use disorder (OUD) continuously poses major public health challenges and social implications worldwide with dramatic rise of opioid dependence leading to potential abuse. Despite that a few pharmacological agents have been approved for OUD treatment, the efficacy of said agents for OUD requires further improvement in order to provide safer and more effective pharmacological and psychosocial treatments. Proteins including mu, delta, kappa, nociceptin, and zeta opioid receptors are the direct targets of opioids and play critical roles in therapeutic treatments. The protein-protein interaction (PPI) networks of the these receptors increase the complexity in the drug development process for an effective opioid addiction treatment. The report below presents a PPI-network informed machine-learning study of OUD. We have examined more than 500 proteins in the five opioid receptor networks and subsequently collected 74 inhibitor datasets. Machine learning models were constructed by pairing gradient boosting decision tree (GBDT) algorithm with two advanced natural language processing (NLP)-based autoencoder and Transformer fingerprints for molecules. With these models, we systematically carried out evaluations of screening and repurposing potential of more than 120,000 drug candidates for four opioid receptors. In addition, absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties were also considered in the screening of potential drug candidates. Our machine-learning tools determined a few inhibitor compounds with desired potency and ADMET properties for nociceptin opioid receptors. Our approach offers a valuable and promising tool for the pharmacological development of OUD treatments.

Sustained drug delivery strategies for treatment of common substance use disorders: Promises and challenges

Substance use disorders (SUDs) are a leading cause of death and other ill health effects in the United States and other countries in the world. Several approaches ranging from detoxification, behavioral therapy, and the use of antagonists or drugs with counter effects are currently being applied for its management. Amongst these, drug therapy is the mainstay for some drug abuse incidences, as is in place specifically for opioid abuse or alcohol dependence. The severity of the havocs observed with the SUDs has triggered constant interest in the discovery and development of novel medications as well as suitable or most appropriate methods for the delivery of these agents. The chronic need of such drugs in users warrants the need for their prolonged or sustained systemic availability. Further, the need to improve patient tolerance to medication, limit invasive drug use and overall treatment outcome are pertinent considerations for embracing sustained release designs for medications used in managing SUDs. This review aims to provide an overview on up-to-date advances made with regards to sustained delivery systems for the drugs for treatment of different types of SUDs such as opioid, alcohol, tobacco, cocaine, and cannabis use disorders. The clinical relevance, promises and the limitations of deployed sustained release approaches along with future opportunities are discussed.

Effectiveness, safety and feasibility of extended-release naltrexone for opioid dependence: a 9-month follow-up to a 3-month randomized trial

BACKGROUND AND AIM

This is a follow-up study of a previously published randomized clinical trial conducted in Norway that compared extended-release naltrexone (XR-NTX) to buprenorphine-naloxone (BP-NLX) over 3 months. At the conclusion of the trial, participants were offered their choice of study medication for an additional 9 months. While BP-NLX was available at no cost through opioid maintenance treatment programmes, XR-NTX was available only through study participation, accounting for why almost all participants chose XR-NTX in the follow-up. The aim of this follow-up study was to compare differences in outcome between adults with opioid dependence continuing XR-NTX and those inducted on XR-NTX for a 9-month period, on measures of effectiveness, safety and feasibility.

DESIGN

In this prospective cohort study, participants were either continuing XR-NTX, changed from BP-NLX to XR-NTX or re-included into the study and inducted on XR-NTX treatment.

SETTING

Five urban, out-patient addiction clinics in Norway.

PARTICIPANTS

Opioid-dependent adults continuing (n = 54) or inducted on (n = 63) XR-NTX.

INTERVENTION

XR-NTX administrated as intramuscular injections (380 mg) every fourth week.

MEASUREMENTS

Data on retention, use of heroin and other illicit substances, opioid craving, treatment satisfaction, addiction-related problems and adverse events were reported every fourth week.

FINDINGS

Nine-month follow-up completion rates were 51.9% among participants continuing XR-NTX in the follow-up and 47.6% among those inducted on XR-NTX. Opioid abstinence rates were, respectively, 53.7 and 44.4%. No significant group differences were found in use of heroin and other opioids.

CONCLUSIONS

Opioid-dependent individuals who elect to switch from buprenorphine-naltrexone treatment after 3 months to extended-release naltrexone treatment for 9 months appear to experience similar treatment completion and abstinence rates and similar adverse event profiles to individuals who had been on extended-release naltrexone from the start of treatment.

Perceptions of alcohol use in the context of HIV treatment: a qualitative study

Background

Alcohol use is associated with poor HIV treatment outcomes. This study aimed to understand patients’ perceptions of the impact of alcohol use in the context of HIV care.

Methods

The study design was a descriptive qualitative study of HIV positive individuals receiving antiretroviral treatment. The study involved four focus group discussions with male and female participants at a tertiary center, city clinic, and rural church. We employed convenience sampling and invited patients coming for their routine visits and medication refills to participate.

Results

Participants had an awareness of both the direct and indirect effects of alcohol use. The direct effects related to the incompatibility of HIV medication and alcohol. The indirect effects related to the negative impact of alcohol on treatment adherence. Participants proffered reasons why HIV infected individuals on HIV treatment drink and felt that patients had to make a deliberate choice to stop drinking. Participants displayed some knowledge of interventions for drinking cessation and highlighted the use of pharmacological interventions to stop drinking. Participants indicated that they preferred HIV counselors to provide counseling services in view of the existing relationships that patients had with counselors.

Conclusion

People living with HIV have adequate knowledge of the effects of alcohol use in the context of HIV treatment. Stigma and the time taken to engage in an alcohol use intervention appeared to be the main impediments to uptake. The current model of HIV treatment, based on trust with the HIV care team, and maintenance of this trust, could bolster the uptake of an intervention. Involvement of HIV patients in their treatment is necessary to improve treatment outcomes in the context of alcohol use.

Treatment and Prevention of Opioid Use Disorder: Challenges and Opportunities

Treatment for opioid use disorder in the United States evolved in response to changing federal policy and advances in science. Inpatient care began in 1935 with the US Public Health Service Hospitals in Lexington, Kentucky, and Fort Worth, Texas. Outpatient clinics emerged in the 1960s to provide aftercare. Research advances led to opioid agonist and opioid antagonist therapies. When patients complete opioid withdrawal, return to use is often rapid and frequently deadly. US and international authorities recommend opioid agonist therapy (i.e., methadone or buprenorphine). Opioid antagonist therapy (i.e., extended-release naltrexone) may also inhibit return to use. Prevention efforts emphasize public and prescriber education, use of prescription drug monitoring programs, and safe medication disposal options. Overdose education and naloxone distribution promote access to rescue medication and reduce opioid overdose fatalities. Opioid use disorder prevention and treatment must embrace evidence-based care and integrate with physical and mental health care.

Alcohol and Opioid Use, Co-Use, and Chronic Pain in the Context of the Opioid Epidemic: A Critical Review

The dramatic increase in opioid misuse, opioid use disorder (OUD), and opioid-related overdose deaths in the United States has led to public outcry, policy statements, and funding initiatives. Meanwhile, alcohol misuse and alcohol use disorder (AUD) are a highly prevalent public health problem associated with considerable individual and societal costs. This study provides a critical review of alcohol and opioid misuse, including issues of prevalence, morbidity, and societal costs. We also review research on interactions between alcohol and opioid use, the influence of opioids and alcohol on AUD and OUD treatment outcomes, respectively, the role of pain in the co-use of alcohol and opioids, and treatment of comorbid OUD and AUD. Heavy drinking, opioid misuse, and chronic pain individually represent significant public health problems. Few studies have examined co-use of alcohol and opioids, but available data suggest that co-use is common and likely contributes to opioid overdose-related morbidity and mortality. Co-use of opioids and alcohol is related to worse outcomes in treatment for either substance. Finally, chronic pain frequently co-occurs with use (and co-use) of alcohol and opioids. Opioid use and alcohol use are also likely to complicate the treatment of chronic pain. Research on the interactions between alcohol and opioids, as well as treatment of the comorbid disorders is lacking. Currently, most alcohol research excludes patients with OUD and there is lack of measurement in both AUD and OUD research in relation to pain-related functioning. Research in those with chronic pain often assesses opioid use, but rarely assesses alcohol use or AUD. New research to examine the nexus of alcohol, opioids, and pain, as well as their treatment, is critically needed.

Practical outpatient pharmacotherapy for alcohol use disorder

Alcohol use disorder (AUD) is commonly encountered in clinical practice. A combination of psychosocial intervention and pharmacotherapy is the cornerstone of AUD treatment. Despite their efficacy, safety and cost-effectiveness, clinicians are reluctant to prescribe medications to treat individuals with AUD. Given the high rate of relapse with psychosocial intervention alone, increasing patient access to this underutilized treatment has the potential to improve clinical outcome in this difficult-to-treat population. Herein, we provide practical pharmacotherapy strategies to improve treatment outcome for AUD. We review the efficacy and side effects of both on- and off-label agents with a particular focus on clinical applicability. Recommendations are supported by findings from randomized controlled trials (RCT) and meta-analyses selected to be representative, where possible, of current treatment guidelines. The goal of this paper is to help readers use pharmacotherapy with greater confidence when treating patients with AUD.

Open-label Study of Injectable Extended-release Naltrexone (XR-NTX) in Healthcare Professionals With Opioid Dependence

OBJECTIVES

Healthcare professionals (HCPs) with opioid dependence are at risk for relapse and death, particularly in the first year of recovery; however, maintenance treatment with opioid agonists is controversial in this safety-sensitive group. We evaluated long-term safety, tolerability, and treatment outcomes of injectable, intramuscular, extended-release naltrexone (XR-NTX) in opioid-dependent HCPs.

METHODS

This single-arm, multisite, open-label study was conducted in opioid-dependent HCPs who had been detoxified from opioids for at least 2 weeks. Subjects received monthly XR-NTX injections for up to 24 months, combined with counseling via intensive outpatient substance abuse treatment programs. Assessments included monthly urine opioid drug tests and routine safety assessments, along with a trimonthly short form (36) Health Survey, opioid craving questionnaire, and Treatment Satisfaction Questionnaire for Medication.

RESULTS

Of 49 opioid-dependent HCPs screened, 38 enrolled and received at least 1 XR-NTX injection. Most were female (n = 31) and nurses or nursing assistants (n = 30). More than half (n = 21; 55.3%) received at least 12 injections. Seven discontinued due to adverse events (3 anxiety, 2 headache, 1 injection-site mass, 1 derealization). None experienced relapses to opioid dependence necessitating detoxification, overdose, or death during treatment. At 24 months, mean opioid craving fell by 45.2%, and short form (36) mental component scores improved by 31.1% from baseline and approached normal levels. Of 22 unemployed subjects at baseline, 45.5% improved employment status at 24 months.

CONCLUSIONS

Long-term (2 years) XR-NTX was associated with no new safety concerns, and, compared with shorter-term studies in the general population, similar or better rates of retention, opioid-negative urines, opioid craving reduction, mental health functional quality of life improvement, and re-employment.

A delayed injection-site reaction in a patient receiving extended-release naltrexone

BACKGROUND

Pharmacotherapy, such as oral naltrexone, has proven effective in treating alcohol use disorder, although medication adherence has presented challenges. Although a formulation of extended-release naltrexone for intramuscular injection has been developed to counter daily adherence issues, injection-site reactions can occur within days of depot injection.

CASE

The authors report a case of an individual with alcohol use disorder who had a previously undescribed delayed injection-site reaction that occurred 11 days after injection. Subsequent challenge with the medication resulted in recurrence of the reaction.

DISCUSSION

Although extended-release naltrexone is generally well tolerated, injection-site reactions can complicate treatment and can appear more than 10 days after medication administration.

Medications for substance use disorders (SUD): emerging approaches

INTRODUCTION

Substance use disorders are a group of chronic relapsing disorders of the brain, which have massive public health and societal impact. In some disorders (e.g., heroin/prescription opioid addictions) approved medications have a major long-term benefit. For other substances (e.g., cocaine, amphetamines and cannabis) there are no approved medications, and for alcohol there are approved treatments, which are not in wide usage. Approved treatments for tobacco use disorders are available, and novel medications are also under study. Areas covered: Medication-based approaches which are in advanced preclinical stages, or which have reached proof-of concept clinical laboratory studies, as well as clinical trials. Expert opinion: Current challenges involve optimizing translation between preclinical and clinical development, and between clinical laboratory studies to therapeutic clinical trials. Comorbidities including depression or anxiety are challenges for study design and analysis. Improved pharmacogenomics, biomarker and phenotyping approaches are areas of interest. Pharmacological mechanisms currently under investigation include modulation of glutamatergic, GABA, vasopressin and κ-receptor function, as well as inhibition of monoamine re-uptake. Other factors that affect potential market size for emerging medications include stigma, availability of treatment settings, adoption by clinicians, and the prevalence of persons with SUD who are not actively treatment-seeking.

A novel non-opioid protocol for medically supervised opioid withdrawal and transition to antagonist treatment

BACKGROUND

The clinical feasibility of a novel non-opioid and benzodiazepine-free protocol was assessed for the treatment of medically supervised opioid withdrawal and transition to subsequent relapse prevention strategies.

METHODS

A retrospective chart review of DSM-IV diagnosed opioid-dependent patients admitted for inpatient medically supervised withdrawal examined 84 subjects (52 males, 32 females) treated with a 4-day protocol of scheduled tizanidine, hydroxyzine, and gabapentin. Subjects also received ancillary medications as needed, and routine counseling. Primary outcomes were completion of medically supervised withdrawal, and initiation of injectable extended release (ER) naltrexone treatment. Secondary outcomes included the length of hospital stay, Clinical Opiate Withdrawal Scale (COWS) scores, and facilitation to substance use disorder treatment intervention. Ancillary medication use and adverse effects were also assessed.

RESULTS

A total of 79 (94%) of subjects completed medically supervised withdrawal. A total of 27 (32%) subjects chose to pursue transition to ER naltrexone, and 24 of the 27 (89%) successfully received the injection prior to hospital discharge. The protocol subjects had a mean length of hospital stay of 3.6 days, and the mean COWS scores was 3.3, 3.4, 2.8, and 2.4 on Day 1, 2, 3, and 4, respectively. Furthermore, 71 (85%) engaged in an inpatient or outpatient substance use disorder (SUD) treatment program following protocol completion.

CONCLUSION

This retrospective chart review suggests the feasibility of a novel protocol for medically supervised opioid withdrawal and transition to relapse prevention strategies, including injectable ER naltrexone. This withdrawal protocol does not utilize opioid agonists or other controlled substances.‬‬‬‬.

Commercial Health Plan Coverage of Selected Treatments for Opioid Use Disorders from 2003 to 2014

Opioid use disorders (OUDs) are receiving significant attention in the U.S. as a public health crisis. Access to treatment for OUDs is essential and was expected to improve following implementation of the federal parity law and the Affordable Care Act. This study examines changes in coverage and management of treatments for OUDs (opioid treatment programs (OTPs) as a covered service benefit, buprenorphine as a pharmacy benefit) before, during, and after parity and ACA implementation. Data are from three rounds of a nationally representative survey conducted with commercial health plans regarding behavioral health services in benefit years 2003, 2010, and 2014. Data were weighted to be representative of health plans' commercial products in the continental United States (2003 weighted N = 7,469, 83% response rate; 2010 N = 8,431, 89% response rate; and 2014 N = 6,974, 80% response rate). Results showed treatment for OUDs was covered by nearly all health plan products in each year of the survey, but the types and patterns varied by year. Prior authorization requirements for OTPs have decreased over time. Despite the promise of expanded access to OUD treatment suggested by parity and the ACA, improved health plan coverage for treatment of OUDs, while essential, is not sufficient to address the opioid crisis.

The Los Angeles County hub-and-provider network for promoting the sustained use of extended-release naltrexone (XR-NTX) in Los Angeles County (2010-2015)

Extended-release naltrexone (XR-NTX) is a medication-assisted treatment (MAT) that is used in conjunction with psychosocial treatment for substance use disorder. It is associated with a reduction in the number of days that patients use alcohol or opioids, in cravings and drug-seeking behaviors, and in healthcare utilization costs, as well as improved medication adherence rates for patients in substance use disorder (SUD) treatment programs and improved quality of life. Despite the clinical effectiveness of XR-NTX, its clinical use has been slow to develop. There is little research describing the utilization of XR-NTX over time at the treatment-system level and few documented attempts to promote MAT by creating a system to explicitly promote and sustain MAT use. This study examines changes between April 1, 2010, and March 30, 2015, in the utilization patterns of XR-NTX for SUDs as promoted and delivered in a system of "medication hubs," comprised of community providers and a medication coordinating center, and training efforts. This system was implemented as part of a large demonstration project that was designed to provide access to XR-NTX in Los Angeles County. Our findings indicated an increase in the initiation of XR-NTX (59% increase) and subsequent doses (89% increase) from Year 1 to Year 5 of the project (p<0.001). These findings suggest that it is possible to improve MAT utilization (in this case XR-NTX) through the use of a system of care that minimizes MAT payment issues for providers and patients, provides an infrastructure (medication hubs and SUD treatment providers), promotes system coordination, and educates providers.

Naltrexone: Not Just for Opioids Anymore

Naltrexone is a semi-synthetic opioid with competitive antagonist activity at mu opioid receptors. Its efficacy has been demonstrated in the treatment of alcohol and opioid dependence, but adherence to daily dosing has been recognized as a factor limiting long-term effectiveness. Recently, a long-acting injectable formulation of naltrexone has received FDA-approval for treating alcohol and opioid dependence. This article reviews the pharmacology of naltrexone, the current evidence supporting the use of extended-release naltrexone, and the clinical challenges in the induction of patients to this medication.

Injectable formulations of poly(lactic acid) and its copolymers in clinical use

Poly(lactic acid) and its copolymers have revolutionized the field of drug delivery due to their excellent biocompatibility and tunable physico-chemical properties. These copolymers have served the healthcare sector by contributing many products to combat various diseases and for biomedical applications. This article provides a comprehensive overview of clinically used products of poly(lactic acid) and its copolymers. Multi-dimension information covering product approval, formulation aspects and clinical status is described to provide a panoramic overview of each product. Moreover, leading patented technologies and various clinical trials on these products for different applications are included. This review focuses on marketed injectable formulations of PLA and its copolymers.

Acceptability of Extended-Release Naltrexone by Heroin-Dependent Patients and Addiction Treatment Providers in the Netherlands

BACKGROUND

Extended-release naltrexone (XRNT) was developed to overcome poor treatment compliance with oral naltrexone in alcohol and opioid-dependent patients. XRNT injections are registered in the United States and Russia, but not in The Netherlands. However, XRNT can be obtained for individual patients, but it is expensive and not reimbursed by the health insurance.

OBJECTIVES

This study evaluates the support for abstinence oriented treatment among heroin-dependent patients and the acceptability of XRNT injections by heroin-dependent patients and treatment providers in The Netherlands.

METHODS

A sample of 261 patients in methadone maintenance treatment or heroin assisted treatment and a sample of 188 addiction treatment providers completed specially designed questionnaires.

RESULTS

The current study shows that many patients in opioid maintenance treatment (58%) report a desire to become abstinent from opioids and that 83% of the patients with a desire for abstinence are interested in XRNT. The majority of treatment providers (81%) are willing to support the prescription of XRNT injections in opioid-dependent patients to prevent relapse after detoxification.

CONCLUSIONS

The current practice of automatic and indefinite continuation of opioid substitution should therefore be reconsidered. However, XRNT injections are very expensive and currently not reimbursed by the health insurance agencies in The Netherlands and thus not really available to most patients.

Prescription drug monitoring program data tracking of opioid addiction treatment outcomes in integrated dual diagnosis care involving injectable naltrexone

BACKGROUND AND OBJECTIVES

Fourfold increases in opioid prescribing and dispensations over 2 decades in the U.S. has paralleled increases in opioid addictions and overdoses, requiring new preventative, diagnostic, and treatment strategies. This study examines Prescription Drug Monitoring Program (PDMP) tracking as a novel measure of opioid addiction treatment outcomes in a university-affiliated integrated mental health-addiction treatment clinic.

METHODS

Repeated measure parametrics examined PDMP and urine drug screening (UDS) data before and after first injection for all patients (N = 68) who received at least one long-acting naltrexone injection (380 mg/IM) according to diagnostic groupings of having either (i) alcohol (control); (ii) opioid; or (iii) combined alcohol and opioid use disorders.

RESULTS

There were no group differences post-injection in treatment days, injections delivered, or treatment service encounters. UDS and PDMP measures of opioid exposures were greater in opioid compared to alcohol-only patients. Post-first injection, UDS's positive for opioids declined (p < .05) along with PDMP measures of opioid prescriptions (p < .001), doses (p < .01), types (p < .001), numbers of dispensing prescribers (p < .001) and pharmacies (p < .001). Opioid patients without alcohol disorders showed the best outcomes with 50% to 80% reductions in PDMP-measures of opioids, down to levels of alcohol-only patients.

CONCLUSIONS

This study shows PDMP utility for measuring opioid addiction treatment outcomes, supporting the routine use of PDMPs in clinical and research settings.

SCIENTIFIC SIGNIFICANCE

These findings demonstrate that opioid addiction in patients with complex addictions and mental illnesses comorbidities can show effective treatment responses as measured by PDMP tracking of decreases in opioid prescriptions to those patients. (Am J Addict 2016;25:557-564).

Naltrexone: A Pan-Addiction Treatment?

Addiction is a major public health problem with few efficacious and safe treatments. The goal of this review is to provide an evidence-based assessment of the therapeutic role of the opioid antagonist naltrexone across the addiction spectrum-substance-based and behavioral. The PubMed database was searched for randomized, placebo-controlled clinical trials that investigated the oral or intramuscular long-acting formulation of naltrexone in substance use disorders or behavioral addictions such as pathological gambling, kleptomania, and trichotillomania. Thirty-nine efficacy studies were retrieved, covering alcohol use disorder (n = 22), opioid use disorder (n = 6), nicotine use disorder (n = 5), stimulant use disorder (n = 2), gambling disorder (n = 2), trichotillomania (n = 1), and kleptomania (n = 1). Despite the very different presentations within and between both addiction categories, the data, as a whole, show consistency in favor of naltrexone's relative efficacy and safety. Given the potential benefit and good tolerability revealed in the studies, the high morbidity associated with addiction, and the dearth of alternate treatments, naltrexone would seem like an underutilized treatment option. Further, naltrexone's seemingly broad anti-addiction efficacy supports a shared role for brain opioid pathways in the pathophysiology of addiction, broadly defined. More studies investigating the efficacy and tolerability of naltrexone and other opioid modulators are warranted. Studies should also further examine the effect of combining psychotherapy with naltrexone, as well as the potential role of naltrexone in treating comorbid addictions.

Access to Addiction Pharmacotherapy in Private Health Plans

BACKGROUND

An increasing number of medications are available to treat addictions. To understand access to addiction medications, it is essential to consider the role of private health plans. To contain medication expenditures, most U.S. health plans use cost-sharing and administrative controls, which may impact physicians' prescribing and patients' use of addiction medications. This study identified health plan approaches to manage access to and utilization of addiction medications (oral and injectable naltrexone, acamprosate, and buprenorphine).

METHODS

Data are from a nationally representative survey of private health plans in 2010 (n=385 plans, 935 products; response rate 89%), compared to the same survey in 2003. The study assessed formulary inclusion, prior authorization, step therapy, overall restrictiveness, and if and how health plans encourage pharmacotherapy.

RESULTS

Formulary exclusions were rare in 2010, with acamprosate excluded most often, by only 9% of products. Injectable naltrexone was covered by 96% of products. Prior authorization was common for injectable naltrexone (85%) and rare for acamprosate (3%). Step therapy policies were used only for injectable naltrexone (41%) and acamprosate (20%). Several medications were often on the most expensive tier. Changes since 2003 include fewer exclusions, yet increased use of other management approaches. Most health plans encourage use of addiction pharmacotherapy, and use a variety of methods to do so.

CONCLUSIONS

Management of addiction medications has increased over time but it is not ubiquitous. However, health plans now also include all medications on formularies and encourage providers to use them, indicating that they value addiction pharmacotherapy as an evidence-based practice.

From unwitnessed fatality to witnessed rescue: Pharmacologic intervention in sudden unexpected death in epilepsy

The mechanisms of sudden unexpected death in epilepsy (SUDEP) have been difficult to define, as most cases occur unwitnessed, and physiologic recordings have been obtained in only a handful of cases. However, recent data obtained from human cases and experimental studies in animal models have brought us closer to identifying potential mechanisms. Theories of SUDEP should be able to explain how a seizure starting in the forebrain can sometimes lead to changes in brainstem cardiorespiratory control mechanisms. Herein we focus on three major themes of work on the causes of SUDEP. First, evidence is reviewed identifying postictal hypoventilation as a major contributor to the cause of death. Second, data are discussed that brainstem serotonin and adenosine pathways may be involved, as well as how they may contribute. Finally, parallels are drawn between SIDS and SUDEP, and we highlight similarities pointing to the possibility of shared pathophysiology involving combined failure of respiratory and cardiovascular control mechanisms. Knowledge about the causes of SUDEP may lead to potential pharmacologic approaches for prevention. We end by describing how translation of this work may result in future applications to clinical care.

Correlates of retention on extended-release naltrexone among persons living with HIV infection transitioning to the community from the criminal justice system

BACKGROUND

The acceptability of and retention on extended-release naltrexone (XR-NTX), an FDA-approved medication for the treatment of alcohol and opioid use disorders, among persons living with HIV disease (PLH) under criminal justice setting (CJS) supervision has not been evaluated to date.

METHODS

Two double-blind placebo-controlled randomized trials of XR-NTX for inmates with HIV disease transitioning to the community with (1) alcohol use disorders (AUDs) or (2) opioid use disorders, are underway. Reasons for not accepting XR-NTX and an evaluation of differences in demographic features between those who were retained on study drug and those who did not return for their second injection post-release are discussed.

RESULTS

70% of eligible persons consented to participate; almost 90% received their first injection; and almost 60% returned for their first injection after release. Variables found to be associated (p<0.10) with returning for the second injection included: not meeting criteria for hazardous drinking (p=0.035; OR 0.424 (CI 0.191-0.941)); being prescribed antiretroviral therapy (p=0.068; OR 2.170 (CI 0.943-4.992)); expressing experiencing serious depression 30 days prior to incarceration (p=0.068; OR 1.889 (CI 0.955-3.737)); not having a positive cocaine urine screen on the day of release (DOR) (p=0.011; OR 0.258 (CI 0.091-0.729)); and not meeting criteria for an AUD plus any substance use disorder (p=0.068; OR 0.521 (CI 0.259-1.048)). Only positive cocaine urine test on DOR was statistically significant after multivariate regression analyses (p=0.005; OR 0.207 (CI 0.068-0.623)).

CONCLUSION

CJS based XR-NTX programs are highly acceptable among PLH, however retention on XR-NTX after release is negatively impacted by relapse to cocaine use.

The effects of continuing care on emerging adult outcomes following residential addiction treatment

BACKGROUND

Professional continuing care services enhance recovery rates among adults and adolescents, though less is known about emerging adults (18-25 years old). Despite benefit shown from emerging adults' participation in 12-step mutual-help organizations (MHOs), it is unclear whether participation offers benefit independent of professional continuing care services. Greater knowledge in this area would inform clinical referral and linkage efforts.

METHODS

Emerging adults (N=284; 74% male; 95% Caucasian) were assessed during the year after residential treatment on outpatient sessions per week, percent days in residential treatment and residing in a sober living environment, substance use disorder (SUD) medication use, active 12-step MHO involvement (e.g., having a sponsor, completing step work, contact with members outside meetings), and continuous abstinence (dichotomized yes/no). One generalized estimating equation (GEE) model tested the unique effect of each professional service on abstinence, and, in a separate GEE model, the unique effect of 12-step MHO involvement on abstinence over and above professional services, independent of individual covariates.

RESULTS

Apart from SUD medication, all professional continuing care services were significantly associated with abstinence over and above individual factors. In the more comprehensive model, relative to zero 12-step MHO activities, odds of abstinence were 1.3 times greater if patients were involved in one activity, and 3.2 times greater if involved in five activities (lowest mean number of activities in the sample across all follow-ups).

CONCLUSIONS

Both active involvement in 12-step MHOs and recovery-supportive, professional services that link patients with these community-based resources may enhance outcomes for emerging adults after residential treatment.

Treating Opioid Dependence With Injectable Extended-Release Naltrexone (XR-NTX): Who Will Respond?

OBJECTIVES

Once-monthly intramuscular extended-release naltrexone (XR-NTX) has demonstrated efficacy for the prevention of relapse in opioid dependence, providing an alternative to agonist or partial agonist maintenance (ie, methadone and buprenorphine). The question remains, for whom is this unique treatment most efficacious and can patient-treatment matching factors be identified?

METHODS

A moderator analysis was conducted on a previously reported 24-week, placebo-controlled, multisite, randomized controlled trial of XR-NTX (n = 126) versus placebo (n = 124) among recently detoxified opioid-dependent adults in Russia, which showed XR-NTX superior to placebo in proportion of opioid abstinent weeks. The moderator analysis examined a dichotomous indicator of good clinical response-achieving at least 90% of weeks abstinent over the 24-week trial. A series of logistic regression models were fit for this outcome as functions of treatment (XR-NTX vs placebo), each baseline moderator variable, and their interactions. The 25 baseline variables included demographics, clinical severity (Addiction Severity Index, SF-36, and Clinical Global Impression-Severity), functioning (EQ-5D), craving, and HIV serostatus (HIV+).

RESULTS

More XR-NTX patients achieved 90% abstinence (64/126, 51%) versus placebo (39/124, 31%; P = 0.002). There were no significant interactions between baseline variables and treatment. There was a significant main effect of Clinical Global Impression-Severity score (P = 0.02), such that higher severity score was associated with a lower rate of Good Clinical Response.

CONCLUSIONS

The absence of significant baseline by treatment interactions indicates that no patient-treatment matching variables could be identified. This suggests that XR-NTX was effective in promoting abstinence from opioids across a range of demographic and severity characteristics.

Extended-Release Naltrexone for Alcohol and Opioid Problems in Missouri Parolees and Probationers

The purpose of this study was to compare the naturalistic outcomes of parolees and probationers with alcohol and/or opioid problems who were treated with extended-release naltrexone (XR-NTX) to those treated with other medication-assisted therapies or psychosocial treatment only. Methods consisted of using intake and discharge data collected as part of SAMHSA's Treatment Episode Data Set (TEDS) assessments, controlling for group differences using propensity scores that were based on a range of intake variables. Results showed that patients receiving XR-NTX had longer durations of care (compared to oral naltrexone and psychosocial treatment only) and were more likely to become abstinent (compared to oral naltrexone, buprenorphine/naloxone, and psychosocial treatment only). Findings were similar for the total sample and those with opioid problems. These XR-NTX results were found in the absence of significant differences in rates of self-help participation. No differences were found in employment or arrests in this relatively short time frame. This study documents the real-world effectiveness study of current FDA-approved addiction medications in parolees/probationers and encourages the use of XR-NTX in such a criminal justice population.

Subchronic administration of short-acting naltrexone has no effect on striatal dopamine transporter availability, food intake or body weight gain in rats

The opioid receptor antagonist naltrexone is successfully used in the treatment of opioid and alcohol dependence. However, questions have been raised about possible anhedonic side effects, because the opioid system is directly involved in hedonic responses to natural rewarding activities, possibly due to its indirect effects on the striatal dopamine transporter (DAT). In order to test this hypothesis, 30 rats were randomized to either a 10-day treatment with 3 mg/kg short-acting naltrexone or vehicle. No significant differences between the groups were found in striatal DAT availability, cumulative food intake (for 48 or 72 h), body weight gain and abdominal fatpad weight. Thus, the results of this study suggest that (sub)chronic treatment with short-acting naltrexone does not induce possible anhedonic effects. However, it cannot be ruled out the anhedonic effect of naltrexone is only short-lived and thus not detected in the current study. Therefore, future studies are needed to study possible acute anhedonic effects at several time points shortly after short-acting naltrexone administration and to directly compare the possible anhedonic effects of long-acting with those of short-acting opioid antagonists.

Effect of extended-release naltrexone on striatal dopamine transporter availability, depression and anhedonia in heroin-dependent patients

RATIONALE

Extended-release naltrexone (XRNT), an opioid receptor antagonist, is successfully used in the treatment of opioid dependence. However, naltrexone treatment of opioid-dependent patients may reduce striatal dopamine transporter (DAT) availability and cause depression and anhedonia.

OBJECTIVES

The aim of this study is to investigate changes in striatal DAT availability and symptoms of depression (Beck Depression Inventory (BDI)) and anhedonia (Snaith Hamilton Pleasure Scale (SHAPS)) before and during XRNT treatment.

METHODS

At baseline, ten detoxified heroin-dependent patients and 11 matched healthy controls underwent [(123)I]FP-CIT single photon emission computed tomography (SPECT) imaging to assess striatal DAT binding. Patients underwent a second SPECT scan 2 weeks after an intramuscular injection with XRNT.

RESULTS

At baseline, the mean binding potential (BPND) in the putamen was at a trend level lower and the mean BDI score was significantly higher in heroin patients (n = 10) than in controls (n = 11) (3.45 ± 0.88 vs. 3.80 ± 0.61, p = 0.067, d = -0.48 and 12.75 ± 7.40 vs. 5.20 ± 4.83, p = 0.019, d = 1.24, respectively). Post hoc analyses in subgroups with negative urine analyses for opioids and cocaine showed significantly lower baseline putamen BPND in heroin patients (n = 8) than controls (n = 10) (3.19 ± 0.43 vs. 3.80 ± 0.64, p = 0.049, d = -1.03). XRNT treatment in heroin patients was not significantly associated with changes in striatal DAT availability (p = 0.348, d = 0.48), but the mean BDI score after XRNT treatment was significantly lower than before treatment (7.75 ± 7.21 vs. 12.75 ± 7.40, p = 0.004, d = -0.68).

CONCLUSIONS

The results of this study suggest that XRNT treatment does not reduce striatal DAT availability and has no significant effect on anhedonia, but is associated with a significant reduction of depressive symptoms.

Lost in translation? Moving contingency management and cognitive behavioral therapy into clinical practice

In the treatment of addictions, the gap between the availability of evidence-based therapies and their limited implementation in practice has not yet been bridged. Two empirically validated behavioral therapies, contingency management (CM) and cognitive behavioral therapy (CBT), exemplify this challenge. Both have a relatively strong level of empirical support but each has weak and uneven adoption in clinical practice. This review highlights examples of how barriers to their implementation in practice have been addressed systematically, using the Stage Model of Behavioral Therapies Development as an organizing framework. For CM, barriers such as cost and ideology have been addressed through the development of lower-cost and other adaptations to make it more community friendly. For CBT, barriers such as relative complexity, lack of trained providers, and need for supervision have been addressed via conversion to standardized computer-assisted versions that can serve as clinician extenders. Although these and other modifications have rendered both interventions more disseminable, diffusion of innovation remains a complex, often unpredictable process. The existing specialty addiction-treatment system may require significant reforms to fully implement CBT and CM, particularly greater focus on definable treatment goals and performance-based outcomes.

A pharmaceutical industry perspective on the economics of treatments for alcohol and opioid use disorders

Individuals with alcohol and/or drug use disorders often fail to receive care, or evidence-based care, yet the literature shows health economic benefits. Comparative effectiveness research is emerging that examines approved approaches in terms of real, total healthcare cost/utilization. Comprehensive retrospective insurance claims analyses are few but tend to be nationally distributed and large. The emerging pattern is that, while treatment in general is cost effective, specific therapeutics can yield different health economic outcomes. Cost/utilization data consistently show greater savings with pharmacotherapies (despite their costs) versus psychosocial treatment alone. All FDA-approved addiction pharmacotherapies (oral naltrexone, extended-release naltrexone, acamprosate, disulfiram, buprenorphine, buprenorphine/naloxone, and methadone) are intended for use in conjunction with psychosocial management, not as stand-alone therapeutics; hence, pharmacotherapy costs must offer benefits in addition to abstinence alone or psychological therapy. Patient persistence is problematic, and (despite its cost) extended-release pharmacotherapy may be associated with lower or no greater total healthcare cost, mostly due to reduced hospitalization. The reviewed studies use rigorous case-mix adjustment to balance treatment cohorts but lack the randomization that clinical trials use to protect against confounding. Unlike trials, however, these studies can offer generalizability to diverse populations, providers, and payment models--and are of particular salience to payers.

Design and methods of a double blind randomized placebo-controlled trial of extended-release naltrexone for HIV-infected, opioid dependent prisoners and jail detainees who are transitioning to the community

BACKGROUND

People with opioid dependence and HIV are concentrated within criminal justice settings (CJS). Upon release, however, drug relapse is common and contributes to poor HIV treatment outcomes, increased HIV transmission risk, reincarceration and mortality. Extended-release naltrexone (XR-NTX) is an evidence-based treatment for opioid dependence, yet is not routinely available for CJS populations.

METHODS

A randomized, double-blind, placebo-controlled trial of XR-NTX for HIV-infected inmates transitioning from correctional to community settings is underway to assess its impact on HIV and opioid-relapse outcomes.

RESULTS

We describe the methods and early acceptability of this trial. In addition we provide protocol details to safely administer XR-NTX near community release and describe logistical implementation issues identified. Study acceptability was modest, with 132 (66%) persons who consented to participate from 199 total referrals. Overall, 79% of the participants had previously received opioid agonist treatment before this incarceration. Thus far, 65 (49%) of those agreeing to participate in the trial have initiated XR-NTX or placebo. Of the 134 referred patients who ultimately did not receive a first injection, the main reasons included a preference for an alternative opioid agonist treatment (37%), being ineligible (32%), not yet released (10%), and lost upon release before receiving their injection (14%).

CONCLUSIONS

Study findings should provide high internal validity about HIV and opioid treatment outcomes for HIV-infected prisoners transitioning to the community. The large number of patients who ultimately did not receive the study medication may raise external validity concerns due to XR-NTX acceptability and interest in opioid agonist treatments.

CLINICAL TRIAL NUMBER

NCT01246401.

Extended-release naltrexone for alcohol and opioid dependence: a meta-analysis of healthcare utilization studies

Through improved adherence, once-monthly injectable extended-release naltrexone (XR-NTX) may provide an advantage over other oral agents approved for alcohol and opioid dependence treatment. The objective of this study was to evaluate cost and utilization outcomes between XR-NTX and other pharmacotherapies for treatment of alcohol and opioid dependence. Published studies were identified through comprehensive search of two electronic databases. Studies were included if they compared XR-NTX to other approved medicines and reported economic and healthcare utilization outcomes in patients with opioid or alcohol dependence. We identified five observational studies comparing 1,565 patients using XR-NTX to other therapies over 6 months. Alcohol dependent XR-NTX patients had longer medication refill persistence versus acamprosate and oral naltrexone. Healthcare utilization and costs was generally lower or as low for XR-NTX-treated patients relative to other alcohol dependence agents. Opioid dependent XR-NTX patients had lower inpatient substance abuse-related utilization versus other agents and $8170 lower total cost versus methadone.

Naltrexone implant treatment for buprenorphine dependence--Mauritian case series

Although substitution therapy with opiate agonist treatments such as methadone and buprenorphine has resulted in a reduction of illicit drug use related harm, such treatment has also resulted in severe problems in some countries where opioid-dependent individuals now inject illicitly sold buprenorphine or buprenorphine-naloxone instead of heroin. There is no approved treatment for buprenorphine dependence. Naltrexone is an opioid antagonist which has been used for the treatment of both alcohol and opioid dependencies. Although both buprenorphine and heroin resemble each other concerning their effects, buprenorphine has a higher affinity to opioid receptors than heroin. Therefore, it is not known if naltrexone can block the psychoactive effects of buprenorphine as it does for heroin. This paper presents observational case series data on the use of a sustained-release naltrexone implant for the treatment of buprenorphine dependence. To the authors' knowledge this is the first use of sustained-release naltrexone for this indication.

Pharmacotherapies for treating opioid use disorder

Opioid use disorder (OUD) is a major public health problem in the United States. It has resulted in devastating consequences for people with this condition, including psychosocial and legal problems, in addition to contraction of infectious diseases such as HIV and hepatitis B and C. Furthermore, this disease can cause fatalities from drug overdoses and drug-drug interactions. OUD shatters families and destroys relationships. Effective treatment is crucial in order to curtail the consequences of this condition. The objective of this article is to provide a review of the pharmacotherapies currently being used to treat OUD.

Improving clinical outcomes for naltrexone as a management of problem alcohol use

Despite being a relatively effective and safe treatment, the clinical management of alcohol abuse/dependence by oral naltrexone can be compromised due to the patient's non-compliance with daily use of this medication. Over the past decade an increasing body of research has suggested that the use of sustained release depot naltrexone preparations can overcome this issue and deliver improved clinical outcomes. However, at the same time, research findings from diverse areas of pharmacogenetics, neurobiology and behavioural psychology have also been converging to identify variables including genetic markers, patient psychosocial characteristics and drug use history differences, or clusters of these variables that play a major role in mediating the response of alcohol abuse/dependent persons to treatment by naltrexone. While this article does not attempt to review all available data pertaining to an individual alcohol dependent patient's response to treatment by naltrexone, it does identify relevant research areas and highlights the importance of data arising from them. The characterization of clinical markers, to identify those patients who are most likely to benefit from naltrexone and to tailor a more individual naltrexone treatment, will ultimately provide significant benefit to both patients and clinicians by optimizing treatment outcome.

Perceived relapse risk and desire for medication assisted treatment among persons seeking inpatient opiate detoxification

Most patients with opioid addiction do not receive medication at the time of discharge from brief inpatient detoxification programs despite the high risk of relapse and the availability of three FDA-approved medications. We surveyed 164 inpatient opioid detoxification patients to assess desire for pharmacotherapy following detoxification program discharge. Participants were predominantly male (71.3%) and 80% had detoxed in the past. Reporting on their most recent previous inpatient detoxification, 27% had relapsed the day they were discharged, 65% within a month of discharge, and 90% within a year of discharge. 63% reported they wanted medication-assisted treatment (MAT) after discharge from the current admission. The odds of desiring a treatment medication increased by a factor of 1.02 for every 1% increase in perceived relapse risk (p<.01). These data suggest patient preference discussions including relapse risk could increase post-detox abstinence.

Extended-release naltrexone (XR-NTX) attenuates brain responses to alcohol cues in alcohol-dependent volunteers: a bold FMRI study

Oral naltrexone reduces heavy drinking, but is less consistent as an abstinence promoter, whereas once-monthly extended-release naltrexone (XR-NTX) also maintains abstinence. The present study sought to determine if alcohol cue reactivity is attenuated by XR-NTX. Twenty-eight detoxified alcohol-dependent adult male and female volunteers received a single i.m. injection of either XR-NTX or placebo under double-blind conditions. An fMRI/cue reactivity procedure was conducted immediately before and two weeks after injection. At baseline, alcohol-related visual and olfactory cues elicited significant increases in orbital and cingulate gyri, inferior frontal and middle frontal gyri. Subsequently, brain activation was significantly altered in XR-NTX-treated individuals. These affected brain regions are associated with the integration of emotion, cognition, reward, punishment, and learning/memory, suggesting that XR-NTX attenuates the salience of alcohol-related cues. Such an effect on brain function may interrupt the processes associated with "slips" and relapse, which may account for XR-NTX's ability to maintain abstinence.

Medications for substance use disorders

In this article, the authors briefly review the pharmacotherapeutic agents that are currently available for the treatment of substance use disorders. Nicotine replacement therapies are most effective for tobacco cessation. Naltrexone, acamprosate, and disulfiram are effective for reducing alcohol use. The most effective pharmacotherapies for opiate use disorders are agonist therapies, including methadone and buprenorphine. The authors also examine recent advances in medication development for other substance use disorders such as stimulant addiction. The role of medication adherence and behavioral treatments and the integration of behavioral and pharmacotherapeutic interventions are also discussed.

Long-acting Preparations in Substance Abuse Management: A Review and Update

Many pharmacological approaches have been used in managing substance use disorders. Conventional pharmacological agents have relatively short durations of action which make them vulnerable to non-adherence and relapse to substance use disorder. To overcome this problem, long-acting preparations have been developed with the aim of reducing the frequency of use and hence improving adherence. This review takes a broad overview of the long-acting preparations available for the management of substance use disorders. The pharmacology, advantages and disadvantages of these preparations are discussed. Many of these preparations hold promise for improving patient outcomes.

Substance Abuse Treatment, HIV/AIDS, and the Continuum of Response for People Who Inject Drugs

The continuum of response (CoR) to HIV/AIDS is a framework for implementation of HIV prevention, care, and treatment programs based on a national strategic plan for HIV/AIDS services. The CoR for people who inject drugs (PWID) is an important extension of the developed CoR to HIV/AIDS. The CoR-PWID employs stakeholders who together plan, develop, pilot, and provide a full range of services that address the various prevention, care/support, and treatment needs of people, families, and communities infected or affected by HIV/AIDS and injection drug use. The CoR-PWID comprises a broad range of services that include but are not limited to the World Health Organization priority interventions for HIV/AIDS prevention, treatment, and care in the health sector and the package of essential interventions for the prevention, treatment, and care of HIV for people who inject drugs. Implementation of these well-defined, essential prevention, care/support, and treatment services, in addition to locally defined needed services, in a coordinated fashion is important to clients, their families, and communities. The CoR-PWID is, therefore, a necessary framework essential for service development for countries that address HIV/AIDS in populations of PWID.

Buprenorphine-mediated transition from opioid agonist to antagonist treatment: state of the art and new perspectives

Constant refinement of opioid dependence (OD) therapies is a condition to promote treatment access and delivery. Among other applications, the partial opioid agonist buprenorphine has been studied to improve evidence-based interventions for the transfer of patients from opioid agonist to antagonist medications. This paper summarizes PubMed-searched clinical investigations and conference papers on the transition from methadone maintenance to buprenorphine and from buprenorphine to naltrexone, discussing challenges and advances. The majority of the 26 studies we examined were uncontrolled investigations. Many small clinical trials have demonstrated the feasibility of in- or outpatient transfer to buprenorphine from low to moderate methadone doses (up to 60-70 mg). Results on the conversion from higher methadone doses, on the other hand, indicate significant withdrawal discomfort, and need for ancillary medications and inpatient treatment. Tapering high methadone doses before the transfer to buprenorphine is not without discomfort and the risk of relapse. The transition buprenorphine-naltrexone has been explored in several pilot studies, and a number of treatment methods to reduce withdrawal intensity warrant further investigation, including the co-administration of buprenorphine and naltrexone. Outpatient transfer protocols using buprenorphine, and direct comparisons with other modalities of transitioning from opioid agonist to antagonist medications are limited. Given its potential salience, the information gathered should be used in larger clinical trials on short and long-term outcomes of opioid agonist-antagonist transition treatments. Future studies should also test new pharmacological mechanisms to help reduce physical dependence, and identify individualized approaches, including the use of pharmacogenetics and long-acting opioid agonist and antagonist formulations.

New medications for substance use disorders: challenges and opportunities

An increased understanding of the biological mechanisms underlying the process of addiction has led to unique molecular targets and strategies for pharmacotherapies against addiction. However, the successful translation of these discoveries will require: 1) a more active engagement of the pharmaceutical sector, 2) partnership with regulatory agencies to arrive at meaningful outcomes for medication approval and 3) a greater involvement of the healthcare system in the screening and treatment of substance use disorders.

Maintenance medication for opiate addiction: the foundation of recovery

Illicit use of opiates is the fastest growing substance use problem in the United States, and the main reason for seeking addiction treatment services for illicit drug use throughout the world. It is associated with significant morbidity and mortality related to human immunodeficiency virus, hepatitis C, and overdose. Treatment for opiate addiction requires long-term management. Behavioral interventions alone have extremely poor outcomes, with more than 80% of patients returning to drug use. Similarly poor results are seen with medication-assisted detoxification. This article provides a topical review of the three medications approved by the Food and Drug Administration for long-term treatment of opiate dependence: the opioid-agonist methadone, the partial opioid-agonist buprenorphine, and the opioid-antagonist naltrexone. Basic mechanisms of action and treatment outcomes are described for each medication. Results indicate that maintenance medication provides the best opportunity for patients to achieve recovery from opiate addiction. Extensive literature and systematic reviews show that maintenance treatment with either methadone or buprenorphine is associated with retention in treatment, reduction in illicit opiate use, decreased craving, and improved social function. Oral naltrexone is ineffective in treating opiate addiction, but recent studies using extended-release naltrexone injections have shown promise. Although no direct comparisons between extended-release naltrexone injections and either methadone or buprenorphine exist, indirect comparison of retention shows inferior outcome compared with methadone and buprenorphine. Further work is needed to directly compare each medication and determine individual factors that can assist in medication selection. Until such time, selection of medication should be based on informed choice following a discussion of outcomes, risks, and benefits of each medication.

Pharmacological enhancement of naltrexone treatment for opioid dependence: a review

PURPOSE: Opioid dependence (OD) is a serious and growing clinical condition with increasing social costs that requires expanding treatment beyond opioid agonist substitution. The opioid antagonist naltrexone has displayed a remarkable association of theoretical effectiveness and poor clinical utility in treating OD due to noncompliant behavior and low acceptability among patients, only partly modified by psychosocial interventions. We reviewed pharmacological studies, including naltrexone depot formulations and combination treatments. METHOD: We searched PubMed for clinical studies on the use of naltrexone implants and slow-release injections in OD, and investigations using adjunct medications to improve naltrexone maintenance therapy of OD. We discussed the results in view of their application to the clinical practice. RESULTS: Significant reduction in opioid use and improved retention in treatment have been found in several studies using depot naltrexone formulations, some of which are controlled clinical trials. Pilot investigations have gathered initial positive results on the use of naltrexone in combination with serotonin reuptake inhibitors, α-2 adrenergic, opioid, and γ-aminobutyric acid agonist medications. CONCLUSION: Current evidence suggests that more research on effectiveness and safety is needed in support of depot naltrexone treatment for OD. Further research comparing slow-release with oral naltrexone and opioid agonist medications will help characterize the role of opioid antagonist-mediated treatment of OD. Preliminary investigations on naltrexone combination treatments suggest the opportunity to continue study of new mixed receptor activities for the treatment of OD and other drug addictions.

Injectable extended-release naltrexone for opioid dependence: a double-blind, placebo-controlled, multicentre randomised trial

BACKGROUND

Opioid dependence is associated with low rates of treatment-seeking, poor adherence to treatment, frequent relapse, and major societal consequences. We aimed to assess the efficacy, safety, and patient-reported outcomes of an injectable, once monthly extended-release formulation of the opioid antagonist naltrexone (XR-NTX) for treatment of patients with opioid dependence after detoxification.

METHODS

We did a double-blind, placebo-controlled, randomised, 24-week trial of patients with opioid dependence disorder. Patients aged 18 years or over who had 30 days or less of inpatient detoxification and 7 days or more off all opioids were enrolled at 13 clinical sites in Russia. We randomly assigned patients (1:1) to either 380 mg XR-NTX or placebo by an interactive voice response system, stratified by site and gender in a centralised, permuted-block method. Participants also received 12 biweekly counselling sessions. Participants, investigators, staff , and the sponsor were masked to treatment allocation. The primary endpoint was the response profile for confirmed abstinence during weeks 5–24, assessed by urine drug tests and self report of non-use. Secondary endpoints were self-reported opioid-free days, opioid craving scores, number of days of retention, and relapse to physiological opioid dependence. Analyses were by intention to treat. This trial is registered at ClinicalTrials.gov, NCT00678418.

FINDINGS

Between July 3, 2008, and Oct 5, 2009, 250 patients were randomly assigned to XR-NTX (n=126) or placebo (n=124). The median proportion of weeks of confirmed abstinence was 90·0% (95% CI 69·9–92·4) in the XR-NTX group compared with 35·0% (11·4–63·8) in the placebo group (p=0·0002). Patients in the XR-NTX group self-reported a median of 99·2% (range 89·1–99·4) opioid-free days compared with 60·4% (46·2–94·0) for the placebo group (p=0·0004). The mean change in craving was –10·1 (95% CI –12·3 to –7·8) in the XR-NTX group compared with 0·7 (–3·1 to 4·4) in the placebo group (p<0·0001). Median retention was over 168 days in the XR-NTX group compared with 96 days (95% CI 63–165) in the placebo group (p=0·0042). Naloxone challenge confirmed relapse to physiological opioid dependence in 17 patients in the placebo group compared with one in the XR-NTX group (p<0·0001). XR-NTX was well tolerated. Two patients in each group discontinued owing to adverse events. No XR-NTX-treated patients died, overdosed, or discontinued owing to severe adverse events.

INTERPRETATION

XR-NTX represents a new treatment option that is distinct from opioid agonist maintenance treatment. XR-NTX in conjunction with psychosocial treatment might improve acceptance of opioid dependence pharmacotherapy and provide a useful treatment option for many patients.

FUNDING

Alkermes.