Psychosocial and treatment correlates of opiate free success in a clinical review of a naltrexone implant program

Types of Medication-Assisted Treatment for Opioid Use Disorder in Turkey: The Perceptions of Inpatients about Treatment Success

OBJECTIVE

The aim of this study was the following. When the different dynamics of agonist or antagonist treatments considered it is assumed that the eligible treatment to the individual may be maintained with high efficacy. Thus, we aimed to examine the difference between treatment methods, considering sociodemographics and positive perception for treatment success.

METHODS

The number of 136 individuals which their ages range between 19-50 and have been getting agonist (buprenorphine/naloxone) or antagonist (naltrexone) treatment because of opioid use disorder while resting in clinics have been evaluated to reveal the factors that may alter their perception about treatment and have been compared with sociodemographic variables and characteristics such as sociotropic and autonomic. Therefore, "Sociodemographic Data Evaluation Form," "Predictive Factors for The Addiction Treatment Success Scale," and "Sociotropy-Autonomy Scale" were used to assess the sociodemographic data, the perception towards factors which have been affected to the treatment and characteristics. The data of the individuals have been collected by the researcher via face-to-face interviews while patients were residential in the clinic.

RESULTS

According to results of our study, it has been detected that there are some differences in the perception of treatment success between individuals who have been getting agonist or antagonist treatments such as treatment method (p<0.05), treatment frequency (p<0.01) and parents' vital statuses (p<0.05).

CONCLUSION

At the end of the study it has been understood that medical and social benefits after the selection of eligible treatment methods which is suitable for individual's perception and characteristics have to be considered.

Serum ionic dysequilibria in clinical opioid dependence: Cross-sectional and longitudinal studies

INTRODUCTION

Despite an increasing awareness that the activity of excitable membranes is determined by the underlying ionic gradients across them, and their importance in drug dependency, we were not able to identify any reports of comparing the electrolyte composition of opioid-dependent and non-addicted controls.

METHODS

Linear regression was used to compare clinical pathology blood results taken from 2699 opioid-dependent patients (ODP) and 5307 medical control (MC) patients on a total of 21,734 occasions for the period 1995-2015. The presence of a hepatitis C antibody test was used to separate OPD and MC patients.

RESULTS

The mean age among ODP and MC was 33.51 ± 0.16 and 37.99 ± 0.23 years, respectively ( p < 0.0001). The groups were 71.5% and 54.2% male ( p < 0.0001). Drug use in this cohort has been reported previously. Analysis of sodium, haemoglobin and albumin were used to exclude marked effects of haemodilution/haemoconcentration. Repeated measures linear regression against age and time showed depressed levels of bicarbonate ( p < 0.0001) and potassium ( p < 0.05) and elevated levels of chloride ( p < 0.025) and anions ( p < 0.01) in ODP in both sexes. Multiple regression in mixed-effects models showed that these effects were all worse in females ( p = 0.0001).

CONCLUSION

This data shows that opioid dependence is associated with significant changes in chloride, potassium, bicarbonate and anions in both sexes, and worse in females. This likely has implications for the electrophysiological properties of excitable membranes. It is consistent with the reported impairment of potassium-chloride exchangers in opioid dependence. Explication of the mechanisms responsible must await further studies.

Precipitants of Substance Abuse Relapse in Ghana

Relapse to substance abuse is a global problem and is conceptualized as an integral component of the recovery process. Global statistics on rates of relapse after substance abuse treatment are disturbingly high, averaging about 75% within a 3- to 6-month duration after treatment. This study sought to gain full understanding of the factors that precipitate relapse among substance abusers in Ghana. Data were collected through in-depth interviews with 15 relapsed substance abusers who were previously treated for substance abuse, and three mental health professionals at a psychiatric rehabilitation unit in Ghana. Findings showed that seven factors, including positive/negative emotional reinforcements, sense of loss, interpersonal conflicts, peer influence, familial, religio-cultural, and treatment-based issues complot to instigate and maintain the relapse cycle. The findings provide valuable insights into the relapse phenomenon in Ghana. Clinicians should actively engage family members in the relapse prevention process, and provide insight into religio-cultural relapse precipitants.

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.

Impact of lifetime opioid exposure on arterial stiffness and vascular age: cross-sectional and longitudinal studies in men and women

OBJECTIVE

To characterise and compare the potentiation of arterial stiffness and vascular ageing by opioids in men and women.

DESIGN

Cross-sectional and longitudinal studies of 576 clinical controls and 687 opioid-dependent patients (ODP) on 710 and 1305 occasions, respectively, over a total of 2382 days (6.52 years), 2006-2011. Methodology Radial pulse wave analysis with Atcor SphygmoCor system (Sydney).

SETTING

Primary care.

CONTROLS

General practice patients with non-cardiovascular disorders, and university student controls. ODP: Patients undergoing clinical management of their opioid dependence. CONTROLS had lower chronological ages (CAs) than ODP (30.0±0.5 vs 34.5±0.3, mean±SEM, p<0.0001). 69.6% and 67.7% participants were men, and 16% and 92.3% were smokers (p<0.0001) for controls and ODP, respectively. 86.3%, 10.3% and 3.4% of ODP were treated with buprenorphine (6.98±0.21 mg), methadone (63.04±4.01 mg) or implant naltrexone, respectively. Body mass index (BMI) was depressed in ODP.

INTERVENTIONS

Nil.

PRIMARY OUTCOME MEASURES

Vascular Reference Age (RA) and the ratio of vascular age to chronological age (RA/CA).

SECONDARY OUTCOME MEASURES

Arterial stiffness including Augmentation Index.

RESULTS

After BMI adjustment, RA in ODP was higher as a function of CA and of time (both p<0.05). Modelled mean RA in control and ODP was 35.6 and 36.3 years (+1.97%) in men, and 34.5 and 39.2 years (+13.43%) in women, respectively. Changes in RA and major arterial stiffness indices were worse in women both as a factor (p = 0.0036) and in interaction with CA (p = 0.0040). Quadratic, cubic and quartic functions of opioid exposure duration outperformed linear models with RA/CA over CA and over time. The opioid dose-response relationship persisted longitudinally after multiple adjustments from p=0.0013 in men and p=0.0073 in women.

CONCLUSIONS

Data show that lifetime opioid exposure, an interactive cardiovascular risk factor, particularly in women, is related to linear, quadratic, cubic and quartic functions of treatment duration and is consistent with other literature of accelerated ageing in patients with OD.

Naltrexone: a review of existing sustained drug delivery systems and emerging nano-based systems

Narcotic antagonists such as naltrexone (NTX) have shown some efficiency in the treatment of both opiate addiction and alcohol dependence. A few review articles have focused on clinical findings and pharmacogenetics of NTX, advantages and limitations of sustained release systems as well as pharmacological studies of NTX depot formulations for the treatment of alcohol and opioid dependency. To date, three NTX implant systems have been developed and tested in humans. In this review, we summarize the latest clinical data on commercially available injectable and implantable NTX-sustained release systems and discuss their safety and tolerability aspects. Emphasis is also laid on recent developments in the area of nanodrug delivery such as NTX-loaded micelles and nanogels as well as related research avenues. Due to their ability to increase the therapeutic index and to improve the selectivity of drugs (targeted delivery), nanodrug delivery systems are considered as promising sustainable drug carriers for NTX in addressing opiate and alcohol dependence.

Impact of opioid pharmacotherapy on arterial stiffness and vascular ageing: cross-sectional and longitudinal studies

Whilst there is a small literature on the cardiovascular toxicity of opiates, there is no detailed antemortem data on non-cardiovascular patient populations. A cross-sectional and longitudinal naturalistic observational study was performed comparing methadone (N = 71)-, buprenorphine (N = 593)-, naltrexone (N = 23)-treated patients with controls (N = 576) on indices of arterial stiffness and vascular age by Pulse Wave Analysis in primary care, 2006-2011. Controls were younger 29.96 ± 0.45 (mean ± SEM) vs. 34.00 ± 0.34-39.22 ± 1.11 years (all P < 0.005) and had fewer smokers (15.9 % vs. 86.9 %-92.96 %, all P < 0.0001). The sex ratio was similar (69.6 vs. 67.7 % male, P = 0.46). These baseline differences were controlled for by multiple regression. Linear regression of vascular age, central augmentation pressure, central augmentation index and other measures against chronologic age showed significant protective effects by treatment group against the treatment standard of methadone, in both sexes in additive and interactive models (all P < 0.02). Interactive terms in treatment type remained significant including all conventional risk factors accounting for differing opiate exposures. The principal findings from multiple regression were confirmed in the time series analysis up to 5 years by repeated measures nonlinear regression. These studies show that the deleterious impact of chronic opiate pharmacotherapy on vascular age and arterial stiffness varies significantly by treatment type.

Duration of opiate exposure as a determinant of arterial stiffness and vascular age in male opiate dependence: a longitudinal study

WHAT IS KNOWN AND OBJECTIVE

Despite intriguing initial and associational studies, there remains little research on opiate-related arterial dysfunction and no longitudinal studies. As opiates act potently via P16INK4A/CDKN2A identified on GWAS screens, and as arterial ageing is a surrogate for organismal ageing, this area is of general concern.

METHODS

Thirty-eight male controls compared with 198 opiate-dependent male patients were studied longitudinally using SphygmoCor pulse wave analysis.

RESULTS AND DISCUSSION

Healthy male controls and opiate-dependent male patients were studied on 125 and 625 occasions, respectively. The mean (±SEM) chronological age (CA) was 42·32 ± 2·22 for controls and 35·04 ± 0·61 for opiate dependent (P = 0·0029). 94·4% and 13·2% smoked tobacco (P < 0·0001). Controlling for BMI and CA, there was a significant time: addictive status interaction for vascular age (P = 0·0127) and central augmentation pressure and index (both P < 0·02). Central systolic and diastolic pressures were also worse over time by addictive status (P < 0·005). At repeated measures multiple regression adjusted for classical risk factors, opiate dose and duration of opiate use remained significant. The dose-duration effect was significant in 8 terms and by time. A similar model quadratic in opiate duration was more powerfully predictive, suggesting the salience of the duration of opiate treatment (AIC 191·6898 and 191·5966, P = 0·0116).

WHAT IS NEW AND CONCLUSION

Data suggest that increased length of opiate dependence is associated with advanced vascular stiffness and ageing and are therefore consistent with accelerated ageing organismally. The superiority of power functions of the opiate duration of exposure underscores the significance of the duration of treatment and of putative senescence induction.

Elevation of central arterial stiffness and vascular ageing in opiate withdrawal: cross-sectional and longitudinal studies

The central cardiovascular impacts of clinical opiate withdrawal have not been explored in detail. Pulse Wave Analysis (SphygmoCor) was conducted in healthy controls and opiate-dependent populations. A total of 1,294 patients (69.2 % male) were studied in quintuplicate on 2,089 occasions. Four groups were studied: control (N = 576), buprenorphine stabilized (N = 592), withdrawal (N = 112) and severe withdrawal (N = 14). Control patients were younger than the other groups (29.96 ± 0.45 years v. 32.53 ± 0.74-39.28 ± 3.86) but had similar sex ratios. Multiple regression was used to correct for the effects of age, and significant exacerbations were found in withdrawal in the vascular age (RA), augmentation index, subendocardial perfusion ratio (SEVR <100; R.R. 2.07 95 % C.I. 1.17-3.68, P = 0.02) and central systolic pressure both as factors themselves and in interactions with age (all P < 0.01). The elevation of modelled RA at 60 years was from 69.66 in controls to 97.54 in withdrawal (40.02 %). The effects on RA were found in both sexes and confirmed on longitudinal analysis. The elevation of RA in withdrawal was most marked after 40 years of age (P = 0.027). These results show increased vascular stiffness and cardiovascular age but reduced subendocardial perfusion in opiate withdrawal. Given the daily recurrent nature of withdrawal, these effects are likely cumulative.

Lifetime opiate exposure as an independent and interactive cardiovascular risk factor in males: a cross-sectional clinical study

Introduction

While several studies have identified an increased incidence of cardiovascular disorders in opiate dependence, neither opiates as a cardiovascular risk factor nor their effect on central arterial function has been considered.

Methods

Pulse wave analysis (SphygmoCor, AtCorMedical Pty Limited, Sydney, NSW, Australia) was undertaken on a cohort of controls and opiate dependent patients and the results compared to their lifetime opiate exposure.

Results

Controls (N = 401) were compared with 465 opiate dependent men. The mean (log) ages were different and were found to be 28.80 ± 0.49 years versus 35.02 ± 0.39 years (P < 0.0001), respectively. Of the opiate dependent group, 87.7% were treated with buprenorphine, 8.8% with methadone, and 3.4% with naltrexone. Multiple regression analysis was used to adjust for chronologic age (CA). At CA of 60 years, the modeled age in the controls was 66.40 years, and that in the addicted group was 73.11 years, an advancement of 6.71 years, or 10.10%. Exacerbations of age dependent changes in central arterial stiffness, central pressures, pulse rate, ejection duration, diastolic duration, and subendocardial perfusion ratio by opiate dependence were all noted (P < 0.05). Current heroin dose, heroin duration, and the dose duration interaction were all significantly related to the vascular (or “reference”) age (RA)/CA ratio (all P < 0.006). After multivariate adjustment, the opiate dose duration was independently predictive of RA (P < 0.02). Opiate dose and/or duration were included in a further 25 terms.

Conclusion

These data show that opiate use is not benign for the male cardiovascular system, but has a dose response relationship to central arterial stiffness and thus cardiovascular aging, acting independently and interactively with established cardiovascular risk factors. These findings imply accelerated organismal aging.

Reduction in arterial stiffness and vascular age by naltrexone-induced interruption of opiate agonism: a cohort study

OBJECTIVE

To prospectively assess if opiate antagonist treatment or the opiate-free status could reverse opiate-related vasculopathy.

DESIGN

Longitudinal Open Observational, Serial 'N of One', over 6.5 years under various treatment conditions: opiate dependence, naltrexone and opiate-free.

SETTING

Primary care, Australia.

PARTICIPANTS

20 opiate-dependent patients (16 males: 16 cases of buprenorphine 4.11±1.17 mg, two of methadone 57.5±12.5 mg and two of heroin 0.75±0.25 g).

INTERVENTION

Studies of central arterial stiffness and vascular reference age (RA) were performed longitudinally by SphygmoCor Pulse Wave Analysis (AtCor, Sydney).

PRIMARY OUTCOMES

Primary outcome was vascular age and arterial stiffness accrual under different treatment conditions.

RESULTS

The mean chronological age (CA) was 33.62±2.03 years. The opiate-free condition was associated with a lower apparent vascular age both in itself (males: p=0.0402 and females: p=0.0360) and in interaction with time (males: p=0.0001 and females: p=0.0004), and confirmed with other measures of arterial stiffness. The mean modelled RA was 38.82, 37.73 and 35.05 years in the opiate, naltrexone and opiate-free conditions, respectively. The opiate-free condition was superior to opiate agonism after full multivariate adjustment (p=0.0131), with modelled RA/CA of 1.0173, 0.9563 and 0.8985 (reductions of 6.1% and 11.9%, respectively).

CONCLUSIONS

Data demonstrate that opiate-free status improves vascular age and arterial stiffness in previous chronic opiate users. The role of opiate antagonist treatment in achieving these outcomes requires future clarification and offers hope of novel therapeutic remediation.

High-sensitivity CRP in opiate addiction: relative and age-dependent elevations

High-sensitivity C-reactive protein (hs-CRP) has been shown to be linked with immune stimulation, but is not well studied over the lifetime in opiate addiction. hs-CRP was measured by standard laboratory methods in substance use disorder (SUD) patients and non-SUD (NSUD) aged 18-48 years. Data were log transformed to improve normality. 1231 SUD were compared with 326 NSUD patients of comparable ages. hs-CRP was 7.46 ± 14.24 versus 4.75 ± 13.40 mg/l (mean ± SD) significantly higher in the SUD group (P < 0.0001), a difference which persisted after exclusion of acutely elevated hs-CRP values (P < 0.0001). In multiple regression with age, addictive status was significant both by itself (P < 0.0001) and in interaction with age (P < 0.0001). At age 40 years, the SUD group had a mean hs-CRP of 3.68 which the NSUD group did not achieve till a modelled age of 157.09 years. In an interactive multivariate regression, interactions between age, addictive status, ALT and AST were significant. These data show that hs-CRP is elevated in opiate dependence both per se, and when controlled for age. Furthermore, they suggest that hs-CRP and immune stimulation seen in opiate addiction may underlie the acceleration of age-related multi-system chronic and coronary atherosclerotic disease well described in opiate dependence.

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.

Naltrexone depot formulations for opioid and alcohol dependence: a systematic review

Naltrexone is an opioid receptor antagonist that blocks the reinforcing effects of opioids and reduces alcohol consumption and craving. It has no abuse potential, mild and transient side effects, and thus appears an ideal pharmacotherapy for opioid dependence. Its effectiveness in alcohol dependence is less evident, but compliance with naltrexone combined with psychosocial support has been repeatedly shown to improve drinking outcomes. Limited compliance with oral naltrexone treatment is a known drawback. Several naltrexone implant and injectable depot formulations are being investigated and provide naltrexone release for at least 1 month. Studies among opioid-dependent patients indicate significant reductions in heroin use, but sample sizes are usually small. In alcohol dependence, two large multicenter trials report alcohol and craving reductions for naltrexone and placebo groups, indicating a significant but moderate effect. The pharmacokinetic profile of the injectable formulation indicates reliable naltrexone release over 1 month at therapeutic levels. Implant formulations releasing naltrexone up to 7 months are reported. Findings on safety and tolerability confirm the generally mild adverse effects described for naltrexone tablets. However, further research on therapeutic levels (i.e., opioid blocking) is warranted. The majority of naltrexone implants lacks approval for regular clinical use and larger longitudinal studies are needed. The available naltrexone depot formulations have the potential to significantly improve medication compliance in opioid and alcohol dependence. In certain circumstances, they may constitute a promising new treatment option.

Epidemiologic and Molecular Pathophysiology of Chronic Opioid Dependence and the Place of Naltrexone Extended-Release Formulations in its Clinical Management

Naltrexone implants and depot injections (NI) are a novel form of treatment for opiate dependence (OD). Major questions relate to their absolute and relative efficacy and safety. Opportunely, six recent clinical trial data from several continents have uniformly provided dramatic evidence of the potent, dose-related and highly significant efficacy of NI, with minimal or manageable accompanying toxicity and safety concerns. The opiate-free lifestyle is attained significantly more often with NI adjusted O.R. = 6.00 (95% C.I. 3.86–9.50), P < 10⁻¹⁰. Other drug use and drug craving are also rapidly reduced. The optimum manner in which to commence NI remains to be established. Of particular relevance is the relative safety of NI compared to the chronic opiate agonists (COA) usually employed, as the long-term toxicity of COA is only just being elucidated. Large population-based studies have found elevated rates of cardiovascular disease, six cancers, liver and respiratory disease, and all-cause mortality in COA. Whilst opiates have been shown to trigger numerous molecular pathways, the most interesting is the demonstration that the opiate morphinan’s nucleus binds to the endotoxin groove of the TLR4-MD2 heterodimer. This has the effect of triggering a low grade endotoxaemic-like state, which over time may account for these protean clinical findings, an effect which is reversed by opiate antagonists. This emerging evidence suggests an exciting new treatment paradigm for OD and a corresponding increase in the role of NI in treatment.

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.

The World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for the biological treatment of substance use and related disorders. Part 2: Opioid dependence

OBJECTIVES

To develop evidence-based practice guidelines for the pharmacological treatment of opioid abuse and dependence.

METHODS

An international task force of the World Federation of Societies of Biological Psychiatry (WFSBP) developed these practice guidelines after a systematic review of the available evidence pertaining to the treatment of opioid dependence. On the basis of the evidence, the Task Force reached a consensus on practice recommendations, which are intended to be clinically and scientifically meaningful for physicians who treat adults with opioid dependence. The data used to develop these guidelines were extracted primarily from national treatment guidelines for opioid use disorders, as well as from meta-analyses, reviews, and publications of randomized clinical trials on the efficacy of pharmacological and other biological treatments for these disorders. Publications were identified by searching the MEDLINE database and the Cochrane Library. The literature was evaluated with respect to the strength of evidence for efficacy, which was categorized into one of six levels (A-F).

RESULTS

There is an excellent evidence base supporting the efficacy of methadone and buprenorphine or the combination of buprenorphine and naloxone for the treatment of opioid withdrawal, with clonidine and lofexidine as secondary or adjunctive medications. Opioid maintenance with methadone and buprenorphine is the best-studied and most effective treatment for opioid dependence, with heroin and naltrexone as second-line medications.

CONCLUSIONS

There is enough high quality data to formulate evidence-based guidelines for the treatment of opioid abuse and dependence. This task force report provides evidence for the efficacy of a number of medications to treat opioid abuse and dependence, particularly the opioid agonists methadone or buprenorphine. These medications have great relevance for clinical practice.

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.

Long-acting injectable versus oral naltrexone maintenance therapy with psychosocial intervention for heroin dependence: a quasi-experiment

OBJECTIVE

To conduct a quasi-experimental comparison of early clinical outcomes between injectable, sustained-release, depot naltrexone formulation versus oral naltrexone maintenance therapy in individuals with opiate dependence.

METHOD

Early retention in treatment and urine-confirmed opiate use in the first 8 weeks postdetoxification were compared between patients (diagnosed as opiate-dependent according to DSM-IV criteria) participating in 2 concurrently run randomized clinical trials of oral (n = 69; patients treated from September 1999 to May 2002) and long-acting injectable (n = 42; patients treated from November 2000 to June 2003) naltrexone maintenance therapy with psychosocial therapy.

RESULTS

Long-acting injectable naltrexone produced significantly better outcome than oral naltrexone on days retained in treatment (F(1,106) = 6.49, P = .012) and for 1 measure of opiate use (F(1,106) = 5.26, P = .024); other measures were not significantly different, but differences were in the same direction. In subanalyses, there were interaction effects between baseline heroin use severity and type of treatment. In subanalyses, heroin users with more severe baseline use showed better retention with oral naltrexone maintenance therapy combined with intensive psychotherapy (behavioral naltrexone therapy) as compared to retention shown by severe heroin users treated with long-acting naltrexone injections combined with standard cognitive-behavioral therapy (χ²(1)= 9.31, P = .002); less severe heroin users evidenced better outcomes when treated with long-acting injectable naltrexone.

CONCLUSIONS

This quasi-experimental analysis provides tentative indications of superior outcomes for heroin-dependent patients treated with long-acting injectable naltrexone compared to oral naltrexone. The finding that heroin users with more severe baseline use achieved better outcomes with oral naltrexone is most probably attributable to the intensive nature of the psychosocial treatments provided and points to the opportunity for continued research in augmenting injectable naltrexone with psychosocial strategies to further improve outcome, especially in individuals with more severe use. The results should be considered exploratory given the quasi-experimental nature of the study.

Favorable mortality profile of naltrexone implants for opiate addiction

Several reports express concern at the mortality associated with the use of oral naltrexone for opiate dependency. Registry controlled follow-up of patients treated with naltrexone implant and buprenorphine was performed. In the study, 255 naltrexone implant patients were followed for a mean (+/- standard deviation) of 5.22 +/- 1.87 years and 2,518 buprenorphine patients were followed for a mean (+/- standard deviation) of 3.19 +/- 1.61 years, accruing 1,332.22 and 8,030.02 patient-years of follow-up, respectively. The crude mortality rates were 3.00 and 5.35 per 1,000 patient-years, respectively, and the age standardized mortality rate ratio for naltrexone compared to buprenorphine was 0.676 (95% confidence interval = 0.014 to 1.338). Most sex, treatment group, and age comparisons significantly favored the naltrexone implant group. Mortality rates were shown to be comparable to, and intermediate between, published mortality rates of an age-standardized methadone treated cohort and the Australian population. These data suggest that the mortality rate from naltrexone implant is comparable to that of buprenorphine, methadone, and the Australian population.

Clinical safety of 1500 mg oral naltrexone overdose

This case represents a clinical overdose of the largest known dose of oral naltrexone, equivalent to the taking of a whole bottle of the oral naltrexone preparation. The patient's intention was to control craving for alcohol and opiates. The patient quickly settled with expectant management. As such it demonstrates that earlier concerns that have been voiced in this area, particularly relating to naltrexone-related hepatotoxicity and depression, may have been overstated, at least in the experience of this patient. This patient's course was marked only by gastric irritation, of which she had some history. As such the present profile provides case report evidence consistent with more robust views of the patient safety of naltrexone itself, and opposing more cautious views. Her polydrug craving was suppressed for a period of 2 weeks, which raises the important question of the mechanism of action of naltrexone's generalised suppression of refractory hedonic consumptive addictive behaviours.

Long-acting depot formulations of naltrexone for heroin dependence: a review

PURPOSE OF REVIEW

The major problem with the oral formulation of naltrexone for heroin dependence is poor compliance (adherence). Long-acting sustained release formulations of naltrexone (implantable and injectable) might help to improve compliance and, thus, increase the efficacy of abstinence-oriented treatment of heroin dependence with naltrexone.

RECENT FINDINGS

There have been several implantable and injectable formulations of naltrexone developed within the last decade. It was demonstrated that some of them are effective and relatively well tolerated medications for relapse prevention in heroin addicts. However, advantages and disadvantages of these new medications have never been systematically analyzed.

SUMMARY

Long-acting sustained release formulations of naltrexone are well tolerated and more effective for relapse prevention in heroin addicts than the oral ones.

Buprenorphine medication versus voucher contingencies in promoting abstinence from opioids and cocaine

During a 12-week intervention, opioid dependent participants (N = 120) maintained on thrice-a-week (M, W, F) buprenorphine plus therapist and computer-based counseling were randomized to receive: (a) medication contingencies (MC = thrice weekly dosing schedule vs. daily attendance and single-day 50% dose reduction imposed upon submission of an opioid and/or cocaine positive urine sample); (b) voucher contingency (VC = escalating schedule for opioid and/or cocaine negative samples with reset for drug-positive samples); or (c) standard care (SC), with no programmed consequences for urinalysis results. VC resulted in better 12-week retention (85%) compared to MC (58%; p = 0.009), but neither differed from SC (76% retained). After adjusting for baseline differences in employment, and compared to SC, the MC group achieved 1.5 more continuous weeks of combined opioid/cocaine abstinence (p = 0.030), while the VC group had 2 more total weeks of abstinence (p = 0.048). Drug use results suggest that both the interventions were efficacious, with effects primarily in opioid rather than cocaine test results. Findings should be interpreted in light of the greater attrition associated with medication-based contingencies versus the greater monetary costs of voucher-based contingencies.

Naltrexone implants after in-patient treatment for opioid dependence: randomised controlled trial

BACKGROUND

Naltrexone has considerable potential in helping to prevent relapse in heroin dependency. A longer-lasting formulation for naltrexone treatment is desirable to further reduce non-adherence and relapse during treatment of opiate dependence.

AIMS

To evaluate the safety and effectiveness of a 6-month naltrexone implant in reducing opioid use after in-patient treatment.

METHOD

A group of 56 abstinence-oriented patients who completed in-patient treatment for opioid dependence were randomly and openly assigned to receive either a 6-month naltrexone implant or their usual aftercare. Drug use and other outcomes were assessed at 6-month follow-up.

RESULTS

Patients receiving naltrexone had on average 45 days less heroin use and 60 days less opioid use than controls in the 180-day period (both P<0.05). Blood tests showed naltrexone levels above 1 ng/ml for the duration of 6 months. Two patients died, neither of whom had received an implant.

CONCLUSIONS

Naltrexone implant treatment safely and significantly reduces opioid use in a motivated population of patients.

Comparative treatment and mortality correlates and adverse event profile of implant naltrexone and sublingual buprenorphine

There is increasing interest in the use of implantable naltrexone as a new treatment for opiate dependence. This center has been one of the leaders in this form of treatment in Australia and has recently completed a registry-controlled review of our mortality data. As part of the study of the safety profile of this therapy, we were interested to review both the treatment correlates of previously presented mortality data and of adverse events. A total of 255 naltrexone implant therapy (NIT) and 2,518 buprenorphine (BUP) patients were followed for 1,322.22 and 8,030.02 patient-years, respectively. NIT patients had significantly longer days in treatment per episode (mean +/- standard deviation, 238.32 +/- 110.11 vs. 46.96 +/- 109.79), total treatment duration (371.21 +/- 284.64 vs. 162.50 +/- 245.76), and mean treatment times but fewer treatment episodes than BUP (all p < .0001). Serious local tissue reaction or infection each occurred in 1% of 200 NIT episodes. These data show that NIT economizes treatment resources without compromising safety concerns.

Improved parameters of metabolic glycaemic and immune function and arterial stiffness with naltrexone implant therapy

Here the dramatic and rapid response of a 54-year-old obese hypertensive man with poorly controlled insulin-dependent diabetes with a 33 year history of high dose heroin use, a 1 year history of refractory ulceration of his hands, ankles and feet, treated coronary artery disease, and the metabolic syndrome, to implantation with long-acting naltrexone implants is presented. In particular his hyperlipidaemia, hyperglycaemia, proinflammatory state, evidence of hepatic and renal insufficiency, arterial stiffness, and extensive and chronic cutaneous ulceration all improved dramatically over just 13 weeks, in association with complete control of his heroin, benzodiazepine, tobacco and cannabis use. The metabolic and vascular benefits were all highly statistically significant. The case is the first to document dramatic and rapid metabolic, immune and vascular improvements in association with clinical naltrexone therapy and are consistent with its likely effects in restoring addiction-related stem cell and immunological deficits.

Endogenous opiates and behavior: 2007

This paper is the thirtieth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2007 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.

Sustained-release naltrexone for opioid dependence

BACKGROUND

Naltrexone is an opioid antagonist which effectively blocks heroin effects. Since opioid dependence treatment with naltrexone tablets suffers from high dropout rates, several depot injections and implants are under investigation. Sustained-release formulations are claimed to be effective, but a systematic review of the literature is lacking.

OBJECTIVES

To evaluate the effectiveness of sustained-release naltrexone for opioid dependence and its adverse effects in different study populations.

SEARCH STRATEGY

The following databases were searched from their inception to November 2007: Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL, LILACS, PsycINFO, ISI Web of Science, trial database at http://clinicaltrials.gov, available NIDA monographs, CPDD and AAAP conference proceedings. The reference lists of identified studies, published reviews and relevant web sides were searched manually. Study authors and drug companies were contacted to obtain any unpublished material or missing data.

SELECTION CRITERIA

To evaluate effectiveness only RCTs were included. To evaluate safety, any clinical trial reporting adverse effects was assessed. Treatment condition was extended to include alcohol dependent subjects and healthy volunteers.

DATA COLLECTION AND ANALYSIS

Reviewers independently evaluated the reports, rated methodological quality and extracted data. Analyses were performed separately for opioid dependent, alcohol dependent and healthy participants.

MAIN RESULTS

Foe effectiveness, one report met inclusion criteria. Two dosages of naltrexone depot injections (192 and 384 mg) were compared to placebo. High-dose significantly increased days in treatment compared to placebo (WMD 21.00, 95% CI 10.68 to 31.32, p<0.0001). High-dose compared to low-dose significantly increased days in treatment (WMD 12.00, 95% CI 1.69 to 22.31, p=0.02). Number of patients retained in treatment did not show significant differences between groups. For adverse effects, seventeen reports met inclusion criteria analyses, six were RCTs. Side effects were significantly more frequent in naltrexone depot groups compared to placebo. In alcohol dependent samples only, adverse effects appeared to be significantly more frequent in the low-dose naltrexone depot groups compared to placebo (RR 1.18, 95% CI 1.02 to 1.36, p=0.02). In the opioid dependent sample, group differences were not statistically significant. Reports on systematic assessment of side effects and adverse events were scarce.

AUTHORS' CONCLUSIONS

There is insufficient evidence to evaluate the effectiveness of sustained-release naltrexone for treatment of opioid dependence. For naltrexone injections, administration site-related adverse effects appear to be frequent, but of moderate intensity and time limited. For a harm-benefit evaluation of naltrexone implants, more data on side effects and adverse events are needed.