Naltrexone in the treatment of heroin dependence: a literature review

Medication Treatment of Opioid Use Disorder

Opioid use disorder (OUD) is a chronic, relapsing condition, often associated with legal, interpersonal, and employment problems. Medications demonstrated to be effective for OUD are methadone (a full opioid agonist), buprenorphine (a partial agonist), and naltrexone (an opioid antagonist). Methadone and buprenorphine act by suppressing opioid withdrawal symptoms and attenuating the effects of other opioids. Naltrexone blocks the effects of opioid agonists. Oral methadone has the strongest evidence for effectiveness. Longer duration of treatment allows restoration of social connections and is associated with better outcomes. Treatments for OUD may be limited by poor adherence to treatment recommendations and by high rates of relapse and increased risk of overdose after leaving treatment. Treatment with methadone and buprenorphine has the additional risk of diversion and misuse of medication. New depot and implant formulations of buprenorphine and naltrexone have been developed to address issues of safety and problems of poor treatment adherence. For people with OUD who do not respond to these treatments, there is accumulating evidence for supervised injectable opioid treatment (prescribing pharmaceutical heroin). Another medication mode of minimizing risk of overdose is take-home naloxone. Naloxone is an opioid antagonist used to reverse opioid overdose, and take-home naloxone programs aim to prevent fatal overdose. All medication-assisted treatment is limited by lack of access and by stigma. In seeking to stem the rising toll from OUD, expanding access to approved treatment such as methadone, for which there remains the best evidence of efficacy, may be the most useful approach.

Opioid antagonists with minimal sedation for opioid withdrawal

BACKGROUND

Managed withdrawal is a necessary step prior to drug-free treatment or as the endpoint of long-term substitution treatment.

OBJECTIVES

To assess the effects of opioid antagonists plus minimal sedation for opioid withdrawal. Comparators were placebo as well as more established approaches to detoxification, such as tapered doses of methadone, adrenergic agonists, buprenorphine and symptomatic medications.

SEARCH METHODS

We updated our searches of the following databases to December 2016: CENTRAL, MEDLINE, Embase, PsycINFO and Web of Science. We also searched two trials registers and checked the reference lists of included studies for further references to relevant studies.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled clinical trials along with prospective controlled cohort studies comparing opioid antagonists plus minimal sedation versus other approaches or different opioid antagonist regimens for withdrawal in opioid-dependent participants.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

Ten studies (6 randomised controlled trials and 4 prospective cohort studies, involving 955 participants) met the inclusion criteria for the review. We considered 7 of the 10 studies to be at high risk of bias in at least one of the domains we assessed.Nine studies compared an opioid antagonist-adrenergic agonist combination versus a treatment regimen based primarily on an alpha2-adrenergic agonist (clonidine or lofexidine). Other comparisons (placebo, tapered doses of methadone, buprenorphine) made by included studies were too diverse for any meaningful analysis. This review therefore focuses on the nine studies comparing an opioid antagonist (naltrexone or naloxone) plus clonidine or lofexidine versus treatment primarily based on clonidine or lofexidine.Five studies took place in an inpatient setting, two studies were in outpatients with day care, two used day care only for the first day of opioid antagonist administration, and one study described the setting as outpatient without indicating the level of care provided.The included studies were heterogeneous in terms of the type of opioid antagonist treatment regimen, the comparator, the outcome measures assessed, and the means of assessing outcomes. As a result, the validity of any estimates of overall effect is doubtful, therefore we did not calculate pooled results for any of the analyses.The quality of the evidence for treatment with an opioid antagonist-adrenergic agonist combination versus an alpha2-adrenergic agonist is very low. Two studies reported data on peak withdrawal severity, and four studies reported data on the average severity over the period of withdrawal. Peak withdrawal induced by opioid antagonists in combination with an adrenergic agonist appears to be more severe than withdrawal managed with clonidine or lofexidine alone, but the average severity over the withdrawal period is less. In some situations antagonist-induced withdrawal may be associated with significantly higher rates of treatment completion compared to withdrawal managed with adrenergic agonists. However, this result was not consistent across studies, and the extent of any benefit is highly uncertain.We could not extract any data on the occurrence of adverse events, but two studies reported delirium or confusion following the first dose of naltrexone. Delirium may be more likely with higher initial doses and with naltrexone rather than naloxone (which has a shorter half-life), but we could not confirm this from the available evidence.Insufficient data were available to make any conclusions on the best duration of treatment.

AUTHORS' CONCLUSIONS

Using opioid antagonists plus alpha2-adrenergic agonists is a feasible approach for managing opioid withdrawal. However, it is unclear whether this approach reduces the duration of withdrawal or facilitates transfer to naltrexone treatment to a greater extent than withdrawal managed primarily with an adrenergic agonist.A high level of monitoring and support is desirable for several hours following administration of opioid antagonists because of the possibility of vomiting, diarrhoea and delirium.Using opioid antagonists to induce and accelerate opioid withdrawal is not currently an active area of research or clinical practice, and the research community should give greater priority to investigating approaches, such as those based on buprenorphine, that facilitate the transition to sustained-release preparations of naltrexone.

A sudden and unprecedented increase in low dose naltrexone (LDN) prescribing in Norway. Patient and prescriber characteristics, and dispense patterns. A drug utilization cohort study

Purpose

Following a TV documentary in 2013, there was a tremendous increase in low dose naltrexone (LDN) use in a wide range of unapproved indications in Norway. We aim to describe the extent of this sudden and unprecedented increase in LDN prescribing, to characterize patients and LDN prescribers, and to estimate LDN dose sizes.

Methods

LDN prescriptions recorded in the Norwegian Prescription Database (NorPD) in 2013 and 2014, and sales data not recorded in NorPD from the only Norwegian LDN manufacturer were included in the study.

Results

According to NorPD, 15 297 patients (0.3% of population) collected at least one LDN prescription. The actual number of users was higher as at least 23% of total sales were not recorded in NorPD. After an initial wave, there was a steady stream of new and persistent users throughout the study period. Median patient age was 52 years, and 74% of patients were female. Median daily dose was 3.7 mg. Twenty percent of all doctors and 71% of general medicine practitioners registered in Norway in 2014 prescribed LDN at least once.

Conclusions

The TV documentary on LDN in Norway was followed by a large increase in LDN prescribing, and the proportion of LDN users went from an insignificant number to 0.3% of the population. There was a high willingness to use and prescribe off label despite limited evidence. Observed median LDN dose, and age and gender distribution were as expected in typical LDN using patients. © 2016 The Authors. Pharmacoepidemiology and Drug Safety Published by John Wiley & Sons Ltd.

'Miracle cure' or 'liquid handcuffs': reporting on naltrexone and methadone in the Australian print media

INTRODUCTION AND AIMS

The news media is an important source of information regarding new developments in medicine and public health interventions. Previous research has indicated that in many cases, reporting on new treatments can be inaccurate or sensationalist. This paper presents analysis of Australian print media reporting on two treatment options for heroin dependence (naltrexone and methadone). The aim of this study was to quantitatively compare the volume and content of Australian print media reporting on these two treatments, one of which had a long history of use in Australia, and the other which was comparatively newer.

DESIGN AND METHODS

The study constituted a quantitative content analysis of a sample of 859 Australian newspaper articles, published over a 10-year period (1997-2007). Each article paragraph was coded for positive outcomes/benefits of treatment, as well as negative outcomes associated with treatment.

RESULTS

The analysis revealed that during this period, the Australian print media was significantly more likely to report the potential positive outcomes of naltrexone treatment, compared with the negative outcomes. In contrast, reporting on methadone focused more on the negative outcomes and side effects.

DISCUSSION AND CONCLUSIONS

The relative frequency by which the benefits of naltrexone were mentioned in this sample of news content is somewhat at odds with the extant efficacy and effectiveness research evidence. The findings suggest that reporting on these treatments in the Australian print media has not been balanced. This type of reporting has potential implications for public attitudes, as well as policy decisions.

Opioid antagonists with minimal sedation for opioid withdrawal

BACKGROUND

Managed withdrawal is a necessary step prior to drug-free treatment or as the end point of long-term substitution treatment.

OBJECTIVES

To assess the effectiveness of opioid antagonists in combination with minimal sedation to manage opioid withdrawal.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3, 2008), MEDLINE (January 1966-July 2008), EMBASE (January 1985-2008 Week 31), PsycINFO (1967 to 7 August 2008) and reference lists of articles.

SELECTION CRITERIA

Controlled studies of interventions involving the use of opioid antagonists in combination with minimal sedation to manage withdrawal in opioid-dependent participants compared with other approaches or different opioid antagonist regimes.

DATA COLLECTION AND ANALYSIS

One author assessed studies for inclusion and undertook data extraction. Inclusion decisions and the overall process were confirmed by consultation between all authors.

MAIN RESULTS

Nine studies (6 randomised controlled trials), involving 837 participants, met the inclusion criteria for the review.The quality of the evidence is low, but suggests that withdrawal induced by opioid antagonists in combination with an adrenergic agonist is more intense than withdrawal managed with clonidine or lofexidine alone, while the overall severity is less. Delirium may occur following the first dose of opioid antagonist, particularly with higher doses (> 25mg naltrexone).In some situations antagonist-induced withdrawal may be associated with significantly higher rates of completion of treatment, comp[ared to withdrawal managed primarily with adrenergic agonists. However, this outcome has not been produced consistently, and the extent of any benefit is highly uncertain.

AUTHORS' CONCLUSIONS

The use of opioid antagonists combined with alpha(2)-adrenergic agonists is a feasible approach to the management of opioid withdrawal. However, it is unclear whether this approach reduces the duration of withdrawal or facilitates transfer to naltrexone treatment to a greater extent than withdrawal managed primarily with an adrenergic agonist.A high level of monitoring and support is desirable for several hours following administration of opioid antagonists because of the possibility of vomiting, diarrhoea and delirium.Further research is required to confirm the relative effectiveness of antagonist-induced regimes, as well as variables influencing the severity of withdrawal, adverse effects, the most effective antagonist-based treatment regime, and approaches that might increase retention in subsequent naltrexone maintenance treatment.

Naltrexone maintenance for heroin dependence: uptake, attrition and retention

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

Economic evaluation of interventions to treat opiate dependence : a review of the evidence

Opiate dependence imposes a significant economic burden on society in terms of treatment-related costs and prevention services, other healthcare costs, the work absenteeism of patients, productivity loss arising from premature death of patients, costs associated with crime, and social welfare expenditure. The objective of this research is to review the literature on economic evaluation of treatment of opiate dependence (including detoxification, maintenance and psychosocial support).A literature review was performed on several electronic databases, including MEDLINE (Ovid), Cochrane Database of Systematic Reviews, NHS Economic Evaluation Library Database (via Cochrane Library), Web of Science, Social Science Citations Index, EMBASE and PsycINFO. A sensitive approach was used in order to maximize the number of articles retrieved; no language or publication year limitations were applied to the searches. A combination of subject heading term searches and natural word searches were used. The Drummond checklist was applied to assess the quality of economic evaluations.A total of 259 articles were considered relevant, with eight review studies identified. The treatment spectrum ranged from detoxification to maintenance treatments involving the use of agonist and/or antagonist treatments. The evidence suggests that, although the quality of economic evaluations is reasonably good, there is a dearth of knowledge about the cost effectiveness of treatments for opiate dependence. The majority of the literature reporting the results of cost-effectiveness analyses used surrogate outcome measures and adopted a narrow treatment provider perspective. Studies that have conducted cost-benefit analyses, in spite of methodological divergences, generally adopted a societal perspective and consistently demonstrated positive economic returns from opiate treatment. A paucity of research examined the extent to which psychosocial or behavioural interventions support or replace conventional pharmacological approaches. Economic evaluation provides a useful framework to assist policy makers in allocating resources across competing needs. Opiate dependence is a considerable burden on society's resources, and treatment provides a cost-beneficial solution to address these consequences. However, to better inform the decision-making process, researchers must continue to produce high-quality, methodological, comparable and scientifically credible economic evaluations.

Post-treatment outcomes of buprenorphine detoxification in community settings: a systematic review

A systematic review was undertaken to examine studies of buprenorphine detoxification that has included post-treatment outcomes as well as more immediate aspects of progress. Studies were required to report details of buprenorphine withdrawal regime and post-treatment outcomes including abstinence rates. Only five studies met these criteria, with buprenorphine regimes lasting 3 days to several weeks, and with variable follow-up. Detoxification completion rates were 65-100%, but relatively few treatment completers were then drug free at their follow-up appointments. In subsequent prescribing, more patients had returned to opioid maintenance than complied with naltrexone. Our preliminary review indicates that buprenorphine is a suitable medication for the process of opiate detoxification but that this newer treatment option has not led to higher rates of abstinence following withdrawal. Further studies are required to more substantially examine abstinence outcomes, as well as characteristics which predict success.

Release of naltrexone on buccal mucosa: Permeation studies, histological aspects and matrix system design

Transbuccal drug delivery has got several well-known advantages especially with respect to peroral way. Since a major limitation in buccal drug delivery could be the low permeability of the epithelium, the aptitude of NLX to penetrate the mucosal barrier was assessed. Ex vivo permeation across porcine buccal mucosa 800 microm thick was investigated using Franz type diffusion cells and compared with in vitro data previously obtained by reconstituted human oral epithelium 100 microm thick. Both fluxes (Js) and permeability coefficients (K(p)) are in accordance, using either buffer solution simulating saliva or natural human saliva. Permeation was evaluated also in presence of chemical enhancers or iontophoresis. No significant differences in penetration rate were observed using chemical enhancers; in contrast, Js and K(p) were extensively affected by application of electric fields. Tablets, designed for Naltrexone hydrochloride (NLX) administration on buccal mucosa, were developed and prepared by direct compression of drug loaded (56%) poly-octylcyanocrylate (poly-OCA) matrices. NLX is slowly discharged from buccal tablets following Higuchian kinetic. Histologically, no signs of flogosis ascribable to NLX and/or poly-OCA were observed, while cytoarchitectural changes due to iontophoresis were detected. Buccal tablets containing NLX may represent a potential alternative dosage form in addiction management.

Opioid maintenance: a comparative review of pharmacological strategies

The use of opioids outside of medical practice is a significant health problem with important social and political implications. Although treatment of opioid dependence is traditionally focused on heroin users, there is increasing recognition that a large number of people become dependent through the use of prescription opioids. The necessity for long-term treatment has also been increasingly recognised. At present, there are several pharmacotherapies available for maintenance treatment, including drugs that are full agonists at the opioid receptor (e.g., methadone, slow-release oral morphine), a partial agonist (buprenorphine) and an opioid antagonist (naltrexone). This review examines the existing strategies, highlights problems associated with their use and discusses the opportunities for new treatment approaches, particularly the use of long-acting formulations.

Opioid antagonists with minimal sedation for opioid withdrawal

BACKGROUND

Managed withdrawal is necessary prior to drug-free treatment. It may also represent the end point of long-term opioid replacement treatment.

OBJECTIVES

To assess the effectiveness of opioid antagonists in combination with minimal sedation to induce withdrawal, in terms of intensity of withdrawal, adverse effects and completion of treatment.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3, 2005, which includes the Cochrane Drugs and Alcohol Group register), MEDLINE (January 1966 to August 2005), EMBASE (January 1985 to August 2005), PsycINFO (1967 to August 2005), and CINAHL (1982 to July 2005) and reference lists of articles.

SELECTION CRITERIA

Experimental interventions involved the use of opioid antagonists in combination with minimal sedation to manage withdrawal in opioid-dependent participants compared with other approaches or different opioid antagonist regime.

DATA COLLECTION AND ANALYSIS

One reviewer assessed studies for inclusion and undertook data extraction and trial quality. Study authors were contacted for additional information.

MAIN RESULTS

Nine studies (5 randomised controlled trials), involving 775 participants, met the inclusion criteria for the review. Withdrawal induced by opioid antagonists in combination with an adrenergic agonist is more intense than withdrawal managed with clonidine or lofexidine alone, but the overall severity is less. Limited data showed that antagonist-induced withdrawal may be more severe when the last opioid used was methadone rather than heroin or another short-acting opioid. Delirium may occur following the first dose of opioid antagonist, particularly with higher doses (> 25mg naltrexone). The studies included suggest there is no significant difference in rates of completion of treatment for withdrawal induced by opioid antagonists, in combination with an adrenergic agonist, compared with adrenergic agonist alone.

AUTHORS' CONCLUSIONS

The use of opioid antagonists combined with alpha2 adrenergic agonists is a feasible approach to the management of opioid withdrawal. However, it is unclear whether this approach reduces the duration of withdrawal or facilitates transfer to naltrexone treatment to a greater extent than withdrawal managed primarily with an adrenergic agonist.A high level of monitoring and support is desirable for several hours following administration of opioid antagonists because of the possibility of vomiting, diarrhoea and delirium. Further research is required to confirm the relative effectiveness of antagonist-induced regimes, as well as variables influencing the severity of withdrawal, adverse effects, the most effective antagonist-based treatment regime, and approaches that might increase retention in subsequent naltrexone maintenance treatment.

A randomized control trial of group counseling in a naltrexone treatment program

This study evaluated the additional effectiveness of a 12-week manualized group counseling program over a structured naltrexone treatment program. The randomized controlled trial, the first of its kind in Australia, was conducted at Turning Point Alcohol and Drug Centre, Melbourne, Australia. Ninety-seven participants received a 50 mg dose of naltrexone daily and were randomized to either the experimental (n = 52) or control (n = 45) conditions. The experimental group received a structured group counseling program, which used a cognitive-behavioral relapse prevention approach. Using intention-to-treat analyses, there was only one statistically significant difference between the groups, with the control group reporting a significantly higher level of physical functioning at Week 6. All participants improved significantly in their level of heroin use and in psychosocial functioning between Baseline and Weeks 6, 12, and 24. It is not possible to conclude from these results whether or not group counseling provides additional benefit to naltrexone treatment.

Serious adverse events in the Australian National Evaluation of Pharmacotherapies for Opioid Dependence (NEPOD)

AIMS

The study estimated serious adverse event (SAE) rates among entrants to pharmacotherapies for opioid dependence, during treatment and after leaving treatment.

DESIGN

A longitudinal study based on data from 12 trials included in the Australian National Evaluation of Pharmacotherapies for Opioid Dependence (NEPOD).

PARTICIPANTS AND SETTINGS

A total of 1244 heroin users and methadone patients treated in hospital, community and GP settings. Intervention Six trials included detoxification; all included treatment with methadone, buprenorphine, levo-alpha-acetyl-methadol (LAAM) or naltrexone.

FINDINGS

During 394 person-years of observation, 79 SAEs of 28 types were recorded. Naltrexone participants experienced 39 overdoses per 100 person-years after leaving treatment (44% occurred within 2 weeks after stopping naltrexone). This was eight times the rate recorded among participants who left agonist treatment. Rates of all other SAEs were similar during treatment versus out of treatment, for both naltrexone-treated and agonist-treated participants. Five deaths occurred, all among participants who had left treatment, at a rate of six per 100 person-years. Total SAE rates during naltrexone and agonist treatments were similar (20, 14 per 100 person-years, respectively). Total SAE and death rates observed among participants who had left treatment were three and 19 times the corresponding rates during treatment.

CONCLUSIONS

Individuals who leave pharmacotherapies for opioid dependence experience higher overdose and death rates compared with those in treatment. This may be due partly to a participant self-selection effect rather than entirely to pharmacotherapy being protective. Clinicians should alert naltrexone treatment patients in particular about heroin overdose risks. Duty of care may extend beyond cessation of dosing.

Antagonist-precipitated heroin withdrawal under anaesthetic prior to maintenance naltrexone treatment: determinants of withdrawal severity

This study sought to characterize antagonist-precipitated heroin withdrawal during and immediately following anaesthesia and to identify the determinants of withdrawal severity and duration in 48 dependent heroin users. Objective withdrawal signs decreased significantly with each naloxone bolus administered under anaesthetic. The cost (amount) of the final heroin administration and the number of hours between last heroin use and commencement of anaesthesia were significant, independent predictors of the severity of withdrawal symptomatology. While 83% (40/48) of participants completed withdrawal according to objective criteria and commenced maintenance naltrexone treatment, almost half (22/48) were unable to commence naltrexone on the day of the procedure due to residual withdrawal signs. Fourteen of these 22 participants subsequently commenced naltrexone (median number of days between admission and commencement of naltrexone was 2, range 1 - 6) while eight left treatment prior to initiation of naltrexone. Significantly fewer of those with more severe withdrawal signs during anaesthesia commenced naltrexone (40% vs. 60%). While the severity and duration of withdrawal symptomatology may be moderated by encouraging participants to reduce (or cease) heroin use close to the time of withdrawal, for a substantial proportion of participants in this study, heroin withdrawal by this antagonist-precipitated procedure was neither rapid nor painless. [Ali R, Thomas P, White J, McGregor C, Danz,C, Gowing L, Stegink A, Athanasos P. Antagonist-precipitated heroin withdrawal under anaesthetic prior to maintenance naltrexone treatment: determinants of withdrawal severity.

Blood morphine levels in naltrexone-exposed compared to non-naltrexone-exposed fatal heroin overdoses

The aim of this study was to investigate the association between prior exposure to naltrexone and increased risk of fatal heroin overdose using a review of toxicology reports for heroin-related fatalities between July 1997 to August 1999 for two groups: those treated with oral naltrexone and those who were not treated. Additional information for the oral naltrexone group was obtained from clinic files. Naltrexone-treated deaths were identified from the patient database at the Australian Medical Procedures Research Foundation (AMPRF), Perth, Western Australia (WA) through the Western Australian Department of Health, Data Linkage Project. Non-treated cases were identified from the database at the Forensic Science Laboratory, State Chemistry Centre (WA). We identified and investigated blood morphine concentrations following 21 fatal heroin overdoses with prior exposure to naltrexone and in 71 non-naltrexone-exposed cases over the same time period. The proportion of deaths where heroin use was a major contributing factor was little different in the non-naltrexone compared to the naltrexone-exposed group. Furthermore, in 'acute opiate toxicity' deaths, blood morphine levels were lower in non-naltrexone-exposed compared with naltrexone-exposed cases. Although there was a higher number of deaths designated as rapid (i.e. occurring within 20 minutes) in the naltrexone-exposed (89%) compared with the non-exposed group (72%) this was not statistically significant. Other drug use in relation to heroin-related fatalities is discussed. Findings do not support the hypothesis that prior exposure to naltrexone increases sensitivity to heroin toxicity.

Characteristics, retention and readmissions of opioid-dependent clients treated with oral naltrexone

The aims of this study were to examine the retention rates of opioid-dependent clients treated with oral naltrexone and identify factors that influence retention in treatment of 981 opioid-dependent clients at a public out-patient clinic in Perth, Western Australia. The average retention period for all clients was 9.0 weeks. The factors associated with longer retention were being employed and referral source. Clients who were employed stayed significantly longer in treatment than unemployed clients. Clients referred from a private clinic were retained in treatment significantly longer than those referred from other sources (X = 10.3 vs. 5.9 weeks). While the majority (80.8%) had one admission to naltrexone treatment, 19.2% presented for readmission, some on three or more occasions in the study period. The median period between the end of the first episode of treatment and commencement of the second was 15.6 weeks. The median period between the end of the second episode of treatment and commencement of the third was 11.4 weeks. Those employed had a higher probability of being retained longer in treatment than those who were unemployed in subsequent treatment episodes. Clinicians should expect that initial retention in naltrexone is likely to be relatively short, and that a substantial proportion of clients will represent for further treatment.

A randomized controlled trial of buprenorphine in the management of short-term ambulatory heroin withdrawal

AIM

To determine whether buprenorphine is more effective than clonidine and other symptomatic medications in managing ambulatory heroin withdrawal.

DESIGN

Open label, prospective randomized controlled trial examining withdrawal and 4-week postwithdrawal outcomes on intention-to-treat.

SETTING

Two specialist, out-patient drug treatment centres in inner city Melbourne and Sydney, Australia.

PARTICIPANTS

One hundred and fourteen dependent heroin users were recruited. Participants were 18 years or over, and with no significant other drug dependence, medical or psychiatric conditions or recent methadone treatment. One hundred and one (89%) participants completed a day 8 research interview examining withdrawal outcomes, and 92 (81%) completed day 35 research interview examining postwithdrawal outcomes.

INTERVENTIONS

Participants randomized to control (n = 56) (up to 8 days of clonidine and other symptomatic medications) or experimental (n = 58) (up to 5 days of buprenorphine) withdrawal groups. Following the 8-day withdrawal episode, participants could self-select from range of postwithdrawal options (naltrexone, substitution maintenance, or counselling).

MEASUREMENTS

Retention in withdrawal; heroin use during withdrawal; and retention in drug treatment 4 weeks after withdrawal.

SECONDARY OUTCOMES

Withdrawal severity; adverse events, and heroin use in the postwithdrawal period.

FINDINGS

The experimental group had better treatment retention at day 8 (86% versus 57%, P = 0.001, 95% CI for numbers needed to treat (NNT) = 3-8) and day 35 (62% versus 39%, P = 0.02, 95% CI for NNT = 4-18); used heroin on fewer days during the withdrawal programme (2.6 +/- 2.5 versus 4.5 +/- 2.3, P < 0.001, 95% CI = 1-2.5 days) and in the postwithdrawal period (9.0 +/- 8.2 versus 14.6 +/- 10, P < 0.01, 95% CI = 1.8-9.4); and reported less withdrawal severity. No severe adverse events reported.

CONCLUSIONS

Buprenorphine is effective for short-term ambulatory heroin withdrawal, with greater retention, less heroin use and less withdrawal discomfort during withdrawal; and increased postwithdrawal treatment retention than symptomatic medications.

A comparison of antagonist-precipitated withdrawal under anesthesia to standard inpatient withdrawal as a precursor to maintenance naltrexone treatment in heroin users: outcomes at 6 and 12 months

To compare two methods of heroin withdrawal, 51 heroin users were randomised to undergo a 1 day precipitated withdrawal procedure using naloxone under anaesthetic. About 50 participants were randomised to receive the current standard inpatient withdrawal treatment using clonidine plus symptomatic medication. Following withdrawal, both groups were offered 9 months of naltrexone treatment and supportive counselling. Outcome measures were: commencement of naltrexone, retention in treatment and heroin use at 6 and 12 months. Significantly more of the precipitated withdrawal group completed withdrawal, commenced naltrexone and stayed in treatment for the first 3 months. Overall, there was a significant reduction in both self-reported heroin use and morphine concentration in hair over the 12 month study period, with participants in the precipitated withdrawal group showing significantly lower morphine concentration at 6 months. Being younger and having a lower level of dependence were predictors of abstinence at 6 and 12 months. The advantage of precipitated withdrawal under anesthesia did not persist beyond 3 months with respect to retention in naltrexone treatment or beyond 6 months with respect to heroin use. Long-term follow-up is crucial in assessing the effects of treatment interventions for heroin dependence.

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

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSIONS

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