Impact of supervision of methadone consumption on deaths related to methadone overdose (1993-2008): analyses using OD4 index in England and Scotland

Risk-factors for methadone-specific deaths in Scotland's methadone-prescription clients between 2009 and 2013

AIM

To quantify gender, age-group and quantity of methadone prescribed as risk factors for drugs-related deaths (DRDs), and for methadone-specific DRDs, in Scotland's methadone-prescription clients.

DESIGN

Linkage to death-records for Scotland's methadone-clients with one or more Community Health Index (CHI)-identified methadone prescriptions during July 2009 to June 2013.

SETTING

Scotland's Prescribing Information System and National Records of Scotland.

MEASUREMENTS

Covariates defined at first CHI-identified methadone prescription, and person-years at-risk (pys) thereafter until the earlier of death-date or 31 December 2013. Methadone-specific DRDs were defined as: methadone implicated but neither heroin nor buprenorphine. Hazard ratios (HRs) were assessed using proportional hazards regression.

FINDINGS

Scotland's CHI-identified methadone-prescription cohort comprised 33,128 clients, 121,254 pys, 1,171 non-DRDs and 760 DRDs (6.3 per 1,000 pys), of which 362 were methadone-specific. Irrespective of gender, methadone-specific DRD-rate, per 1,000 pys, was higher in the 35+ age-group (4.2; 95% CI: 3.6-4.7) than for younger clients (1.9; 95% CI: 1.5-2.2). For methadone-specific DRDs, age-related HRs (e.g., 2.9 at 45+ years; 95% CI: 2.1-3.9) were steeper than for all DRDs (1.9; 95% CI: 1.5-2.4); there was no hazard-reduction for females; no gender by age-group interaction; and, unlike for all DRDs, the highest quintile for quantity of prescribed methadone at cohort-entry (>1960mg) was associated with increased HR (1.8; 95% CI: 1.3-2.5).

CONCLUSION

Higher methadone-specific DRD rates in older clients, irrespective of gender, call for better understanding of methadone's pharmaco-dynamics in older, opioid-dependent clients, many with progressive physical or mental ill-health.

The Future of Opioid Agonist Therapies in Ukraine: A Qualitative Assessment of Multilevel Barriers and Ways Forward to Promote Retention in Treatment

Opioid agonist therapies (OAT) to treat opioid addiction in people who inject drugs (PWID) began in Ukraine in 2004. Scale-up of OAT, however, has been hampered by both low enrollment and high attrition. To better understand the factors influencing OAT retention among PWID in Ukraine, qualitative data from 199 PWIDs were collected during 25 focus groups conducted in five Ukrainian cities from February to April 2013. The experiences of PWID who were currently or previously on OAT or currently trying to access OAT were analyzed to identify entry and retention barriers encountered. Transcribed data were analyzed using a grounded theory approach. Individual beliefs about OAT, particularly misaligned treatment goals between clients and providers, influenced PWID's treatment seeking behaviors. Multiple programmatic and structural issues, including inconvenient hours and treatment site locations, complicated dosing regimens, inflexible medication dispensing guidelines, and mistreatment by clinic and medical staff also strongly influenced OAT retention. Findings suggest the need for both programmatic and policy-level structural changes such as revising legal regulations covering OAT dispensing, formalizing prescription dosing policies and making OAT more available through other sites, including primary care settings as a way to improve treatment retention. Quality improvement interventions that target treatment settings could also be deployed to overcome healthcare delivery barriers. Additional patient education and medical professional development around establishing realistic treatment goals as well as community awareness campaigns that address the myths and fears associated with OAT can be leveraged to overcome individual, family and community-level barriers.

Fatal toxicity index of medicinal drugs based on a comprehensive toxicology database

The fatal toxicity index (FTI) is the absolute number of fatal poisonings caused by a particular drug divided by its consumption figure. Consequently, it is a useful measure in evaluating toxicity of the drug and its relevance in fatal poisonings. In this study, we assessed the FTI of medicinal drugs in 3 years (2005, 2009, and 2013) in Finland. As the measure of drug consumption, we used the number of defined daily doses (DDD) per population in each year. There were 70 medicinal drugs in Finland for which the mean FTI expressed as the number of deaths per million DDD over the three study years was higher or equal to 0.1. The Anatomical Therapeutic Chemical (ATC) classification system was used for the classification of the active ingredients of medicinal drugs according to the organ or system which they act on. Of these 70 drugs, 55 drugs (78.6 %) acted on the nervous system (denoted by ATC code N), 11 (15.7 %) on the cardiovascular system (C), three (4.3 %) on the alimentary tract and metabolism (A), and one (1.4 %) on the musculoskeletal system (M). The nervous system drugs consisted of 20 psycholeptics, (ATC code N05), 20 psychoanaleptics (N06), eight analgesics (N02), six antiepileptics (N03), and one other nervous system drug (N07). The highest individual FTIs were associated with the opioids methadone, dextropropoxyphene, oxycodone, tramadol, and morphine; the antipsychotics levomepromazine and chlorprothixene; and the antidepressants doxepin, amitriptyline, trimipramine, and bupropion. Buprenorphine was not included in the study, because most of the fatal buprenorphine poisonings were due to smuggled tablets. A clearly increasing trend in FTI was observed with pregabalin and possibly with bupropion, both drugs emerging as abused substances.

How to overcome hurdles in opiate substitution treatment? A qualitative study with general practitioners in Belgium

BACKGROUND

Opiate substitution treatment (OST) is the administration of opioids (methadone or buprenorphine) under medical supervision for opiate addiction. Several studies indicate a large unmet need for OST in general practice in Antwerp, Belgium. Some hurdles remain before GPs engage in OST prescribing.

OBJECTIVES

Formulate recommendations to increase engagement of GPs in OST, applicable to Belgium and beyond.

METHODS

In 2009, an exploratory qualitative research was performed using focus group discussions and interviews with GPs. During data collection and analysis, purposive sampling, open and axial coding was applied. The script was composed around the advantages, disadvantages and conditions of engaging in OST in general practice.

RESULTS

We conducted six focus groups and two interviews, with GPs experienced in prescribing OST (n = 13), inexperienced GPs (n = 13), and physicians from addiction centres (n = 5). Overall, GPs did not seem very willing to prescribe OST for opiate users. A lack of knowledge about OST and misbehaving patients creates anxiety and makes the GPs reluctant to learn more about OST. The GPs refer to a lack of collaboration with the addiction centres and a need of support (from either addiction centres or experienced GP-colleagues for advice). Important conditions for OST are acceptance of only stable opiate users and more support in emergencies.

CONCLUSION

Increasing GPs' knowledge about OST and improving collaboration with addiction centres are essential to increase the uptake of OST in general practice. Special attention could be paid to the role of more experienced colleagues who can act as advising physicians for inexperienced GPs.

The Impact of Misuse and Diversion of Opioid Substitution Treatment Medicines: Evidence Review and Expert Consensus

BACKGROUND/AIMS

Opioid substitution treatment (OST) improves outcomes in opioid dependence. However, controlled drugs used in treatment may be misused or diverted, resulting in negative treatment outcomes. This review defines a framework to assess the impact of misuse and diversion.

METHODS

A systematic review of published studies of misuse and diversion of OST medicines was completed; this evidence was paired with expert real-world experience to better understand the impact of misuse and diversion on the individual and on society.

RESULTS

Direct impact to the individual includes failure to progress in recovery and negative effects on health (overdose, health risks associated with injecting behaviour). Diversion of OST has impacts on a community that is beyond the intended OST recipient. The direct impact includes risk to others (unsupervised use; unintended exposure of children to diverted medication) and drug-related criminal behavior. The indirect impact includes the economic costs of untreated opioid dependence, crime and loss of productivity.

CONCLUSION

While treatment for opioid dependence is essential and must be supported, it is vital to reduce misuse and diversion while ensuring the best possible care. Understanding the impact of OST misuse and diversion is key to defining strategies to address these issues.

Risk of mortality on and off methadone substitution treatment in primary care: a national cohort study

AIM

To assess whether risk of death increases during periods of treatment transition, and investigate the impact of supervised methadone consumption on drug-related and all-cause mortality.

DESIGN

National Irish cohort study.

SETTING

Primary care.

PARTICIPANTS

A total of 6983 patients on a national methadone treatment register aged 16-65 years between 2004 and 2010.

MEASUREMENT

Drug-related (primary outcome) and all-cause (secondary outcome) mortality rates and rate ratios for periods on and off treatment; and the impact of regular supervised methadone consumption.

RESULTS

Crude drug-related mortality rates were 0.24 per 100 person-years on treatment and 0.39 off treatment, adjusted mortality rate ratio 1.63 [95% confidence interval (CI) = 0.66-4.00]. Crude all-cause mortality rate per 100 person-years was 0.51 on treatment versus 1.57 off treatment, adjusted mortality rate ratio 3.64 (95% CI = 2.11-6.30). All-cause mortality off treatment was 6.36 (95% CI = 2.84-14.22) times higher in the first 2 weeks, 9.12 (95% CI = 3.17-26.28) times higher in weeks 3-4, compared with being 5 weeks or more in treatment. All-cause mortality was lower in those with regular supervision (crude mortality rate 0.60 versus 0.81 per 100 person-years) although, after adjustment, insufficient evidence exists to suggest that regular supervision is protective (mortality rate ratio = 1.23, 95% CI = 0.67-2.27).

CONCLUSIONS

Among primary care patients undergoing methadone treatment, continuing in methadone treatment is associated with a reduced risk of death. Patients' risk of all-cause mortality increases following treatment cessation, and is highest in the initial 4-week period.

Impact of opioid substitution therapy for Scotland's prisoners on drug-related deaths soon after prisoner release

AIM

To assess whether the introduction of a prison-based opioid substitution therapy (OST) policy was associated with a reduction in drug-related deaths (DRD) within 14 days after prison release.

DESIGN

Linkage of Scotland's prisoner database with death registrations to compare periods before (1996-2002) and after (2003-07) prison-based OST was introduced.

SETTING

All Scottish prisons.

PARTICIPANTS

People released from prison between 1 January 1996 and 8 October 2007 following an imprisonment of at least 14 days and at least 14 weeks after the preceding qualifying release.

MEASUREMENTS

Risk of DRD in the 12 weeks following release; percentage of these DRDs which occurred during the first 14 days.

FINDINGS

Before prison-based OST (1996-2002), 305 DRDs occurred in the 12 weeks after 80 200 qualifying releases, 3.8 per 1000 releases [95% confidence interval (CI) = 3.4-4.2]; of these, 175 (57%) occurred in the first 14 days. After the introduction of prison-based OST (2003-07), 154 DRDs occurred in the 12 weeks after 70 317 qualifying releases, a significantly reduced rate of 2.2 per 1000 releases (95% CI = 1.8-2.5). However, there was no change in the proportion which occurred in the first 14 days, either for all DRDs (87: 56%) or for opioid-related DRDs.

CONCLUSIONS

Following the introduction of a prison-based opioid substitution therapy (OST) policy in Scotland, the rate of drug-related deaths in the 12 weeks following release fell by two-fifths. However, the proportion of deaths that occurred in the first 14 days did not change appreciably, suggesting that in-prison OST does not reduce early deaths after release.

Factors associated with illicit methadone injecting in a Canadian setting

BACKGROUND AND OBJECTIVES

While methadone is well established as an evidence-based treatment for opioid use disorder, safety concerns persist regarding its diversion. The authors examine the prevalence of and risk factors associated with injection of methadone in an urban population.

METHODS

Between December 2005 and November 2013, data were derived from two open prospective studies of persons who inject drugs (PWID) in Vancouver, Canada. Generalized estimating equations (GEE) logistic regression was used to determine factors independently associated with illicit methadone injecting.

RESULTS

During the study, 1911 individuals (34% women) were recruited; 134 (7%) participants reported methadone injecting at least once. In multivariable analysis, Caucasian ethnicity [adjusted odds ratio (AOR) = 1.90, 95% confidence interval (CI) = 1.20-3.00]; homelessness (AOR = 1.46, 95% CI = 1.09-1.95); drug dealing (AOR = 2.10, 95% CI = 1.50-2.93); ≥daily heroin injection (AOR = 1.57, 95% CI = 1.08-2.26); ≥daily crack smoking (AOR = 2.06, 95% CI = 1.44-2.95); being a victim of violence (AOR = 1.48, 95% CI = 1.04-2.12); and non-fatal overdose (AOR = 1.67, 95% CI = 1.67 (1.00-2.79) were independently and positively associated with methadone injection; female gender (AOR = 0.47, 95% CI = 0.30-0.75) was negatively associated.

DISCUSSION AND CONCLUSIONS

The diversion of methadone for illicit injection in this urban setting was associated with several markers of addiction severity and other health and social vulnerabilities.

SCIENTIFIC SIGNIFICANCE

These findings underscore the need to ensure methadone accessibility while limiting diversion-related risk.

Death matters: understanding heroin/opiate overdose risk and testing potential to prevent deaths

AIMS

To describe work undertaken over a 20-year period, investigating overdose characteristics among survivors, effects of acute heroin administration, clustering of risk of overdose fatality and potential interventions to reduce this fatal outcome.

METHODS

Privileged-access interviewers obtained data from non-treatment as well as treatment samples; experimental study of drop in oxygen saturation following heroin/opiate injection; investigation of clusterings of death following prison release and treatment termination; and study of target populations as intervention work-force, including family as well as peers, and action research built into pilot implementation.

RESULTS

Overdose has been experienced by about half of heroin/opiate misusers, with even higher proportions having witnessed an overdose, and with high levels of willingness to intervene. Heroin/opiates are associated with the majority of drug-related deaths, despite relative scarcity of use. Heroin injection causes a rapid drop in oxygen saturation, recovering only slowly over the next half hour. Deaths from drug overdose are greatly more likely on prison release and post-discharge from detoxification and other in-patient or residential settings. High levels of declared willingness to intervene are matched by active interventions. Both drug-using peers and family members show ability to improve knowledge and gain confidence from training. Audit study of take-home schemes finds approximately 10% of dispensed naloxone is used in real-life emergency situations.

CONCLUSIONS

Overdose is experienced by most users, with heroin/opiates contributing disproportionately to drug overdose deaths. High-risk times (e.g. after prison release) are now clearly identified. Peers and family are a willing potential intervention work-force, but are rarely trained or given pre-supply of naloxone. Large-scale naloxone provision (e.g. national across Scotland and Wales) is now being delivered, while large-scale randomized trials (e.g. N-ALIVE prison-release trial) are finally under way. Better naloxone products and better-organized provision are needed. The area does not need more debate; it now needs proper implementation alongside good scientific study.

The relative risk of fatal poisoning by methadone or buprenorphine within the wider population of England and Wales

OBJECTIVE

To examine the population-wide overdose risk emerging from the prescription of methadone and buprenorphine for opioid substitution treatment in England and Wales.

DESIGN

Retrospective administrative data study.

SETTING

National databases for England and Wales.

PARTICIPANTS/CASES

Drug-related mortality data were drawn from the Office for National Statistics, and prescription data for methadone and buprenorphine were obtained from the National Health Service for the years 2007-2012. During this 6-year period, a total of 2366 methadone-related deaths and 52 buprenorphine-related deaths were registered, corresponding to 17,333,163 methadone and 2,602,374 buprenorphine prescriptions issued. The analysis encompassed poisoning deaths among members of the wider population of England and Wales who consumed, but were not prescribed these medications, in addition to patients prescribed methadone or buprenorphine.

MAIN OUTCOME MEASURES

Mortality risk: substance-specific overdose rate per 1000 prescriptions issued; relative risk ratio of methadone in relation to buprenorphine.

RESULTS

During the years 2007-2012, the pooled overdose death rate was 0.137/1000 prescriptions of methadone, compared to 0.022/1000 prescriptions of buprenorphine (including buprenorphine-naloxone). The analysis generated a relative risk ratio of 6.23 (95% CI 4.79 to 8.10) of methadone in relation to buprenorphine. UK Borders Agency data were taken into consideration and revealed that only negligible amounts of methadone and buprenorphine were seized on entering UK territory between 2007 and 2012, suggesting domestic diversion.

CONCLUSIONS

Our analysis of the relative safety of buprenorphine and methadone for opioid substitution treatment reveals that buprenorphine is six times safer than methadone with regard to overdose risk among the general population. Clinicians should be aware of the increased risk of prescribing methadone, and tighter regulations are needed to prevent its diversion.

Diversion of methadone and buprenorphine from opioid substitution treatment: the importance of patients' attitudes and norms

AIMS

Methadone and buprenorphine diversion by patients in opioid substitution treatment (OST) is a poorly understood phenomenon. We study the norms and attitudes on diversion among OST patients, including the role these norms and attitudes play as diversion risk factors. We also study whether perceived quality of care, social bonds to treatment staff, and deterrence can be associated with diversion.

METHODS

Structured interviews were conducted with 411 patients from eleven OST programs. In total, 280 interviews were done on site by the researchers, while 131 interviews were conducted through peer interviewing by specially trained patients. The data was analyzed through frequency- and averages-calculations, cross-tabulations, and logistic regression analysis.

RESULTS

Most patients consider diversion as mostly positive (83.7%), morally right (76.8%), and without any significant risk of detection (66.9%). Individual differences in norms and risk perceptions may play a role in explaining variations in diversion; patients who consider it right to share medication with friends report higher treatment-episode diversion than other patients (OR 1.455, p = 0.016). Patients who perceive control measures as effective report lower diversion than other patients (OR = 0.655, p = 0.013). Furthermore, data indicate that patients who are satisfied with the care and service are less prone to engage in diversion. Social bonds with treatment staff seem to be less importance.

CONCLUSIONS

The norm system described by patients resemble Bourgois' 'moral economy of sharing' concept-not sharing drugs with friends in withdrawal is considered unethical. Efforts to decrease diversion may focus on lifestyle-changing interventions, and reducing black market demand for illicit medications by expanding access to treatment.

Long-term self-treatment with methadone or buprenorphine as a response to barriers to opioid substitution treatment: the case of Sweden

Background

It is well known that illicit use of methadone and buprenorphine is common among people with an opioid dependence. Less notice has been taken of the fact that these substances are also used for extended periods of self-treatment, as a way of handling barriers to OST. In this study, motives for self-treatment are investigated, as well as attitudes and perceived barriers to OST among drug users with an opioid dependence in Sweden.

Method

The study is based on qualitative research interviews with 27 opioid users who have treated themselves with methadone or buprenorphine for a period of at least three months.

Results

The duration of self-treatment among the interviewees varied from 5 months to 7 years. Self-treatment often began as a result of a wish to change their life situation or to cut back on heroin, in conjunction with perceived barriers to OST. These barriers consisted of (1) difficulties in gaining access to OST due to strict inclusion criteria, limited access to treatment or a bureaucratic and arduous assessment process, (2) difficulties remaining in treatment, and (3) ambivalence toward or reluctance to seek OST, primarily due to a fear of stigmatization or disciplinary action. Self-treatment was described as an attractive alternative to OST, as a stepping stone to OST, and as a way of handling waiting lists, or as a saving resource in case of involuntary discharge.

Conclusion

Illicit use of methadone and buprenorphine involve risks but may also have important roles to play for users who are unwilling or not given the opportunity to enter OST. A restrictive and strict rehabilitation-oriented treatment model may force many to manage their own treatment. More generous inclusion criteria, a less complex admission process, fewer involuntary discharges, and less paternalistic treatment may lead to increasing numbers seeking OST. Control measures are necessary to prevent diversion and harmful drug use but must be designed in such a way that they impose as few restrictions as possible on the daily life of patients.

Illicit use of opioid substitution drugs: prevalence, user characteristics, and the association with non-fatal overdoses

BACKGROUND AND AIMS

Diversion of opioid substitution drugs (OSD) is of public concern. This study examined the prevalence, frequency, and predictors of illicit OSD use in a group of injecting drug users (IDUs) and assessed if such use was associated with non-fatal overdoses.

METHODS

Semi-annual cross-sectional interviews conducted in Oslo, Norway (2006-2013), from 1355 street-recruited IDUs. Hurdle, logistic, and multinomial regression models were employed.

RESULTS

Overall, 27% reported illicit OSD use in the past four weeks; 16.8% methadone, 12.5% buprenorphine, and 2.9% both drugs. Almost 1/10 reported at least one non-fatal overdose in the past four weeks, and roughly 1/3 reported such experience in the past year. Use of additional drugs tended to be equally, or more prevalent among illicit OSD users than other IDUs. In terms of illicit OSD use being a risk factor for non-lethal overdoses, our results showed significant associations only for infrequent buprenorphine use (using once or less than once per week). Other factors associated with non-fatal overdoses included age, education, homelessness, as well as the benzodiazepines, stimulants, and heroin use.

CONCLUSIONS

Users of diverted OSD may represent a high-risk population, as they used more additional drugs and used them more frequently than other IDUs. However, illicit OSD use may be less harmful than previously assumed. After accounting for an extensive set of covariates, only infrequent illicit buprenorphine use, but not methadone use, was associated with non-fatal overdoses.

Diversion of methadone and buprenorphine from opioid substitution treatment: a staff perspective

Opioid substitution treatment (OST) is still controversial, despite positive results. The issue of diversion to the illicit drug market is a cornerstone in the criticism typically voiced against the treatment. Little research is available concerning how professionals who work in OST view the issue of diversion. In this article, we discuss existing ideas and attitudes toward diversion of methadone and buprenorphine among OST staff in Sweden. The article is based on semi-structured interviews with 25 professionals working in eight OST-programs in southern Sweden. Diversion was seen as a deleterious phenomenon by the interviewees. Three problematic aspects were highlighted: medical risks in the form of overdose fatalities and the recruitment of new opiate/opioid users; negative consequences for the legitimacy of OST; and moral objections, since diversion means that the patients remain in a criminal environment. However, positive aspects were also highlighted. Illicit methadone or buprenorphine is perceived as safer than heroin. In this way, diversion can fulfill a positive function; for instance, if there is a shortage of access to regular treatment. Patients who share their medication with opioid-dependent friends are seen as less culpable than those who sell to anyone for money.

HIV risk reduction with buprenorphine-naloxone or methadone: findings from a randomized trial

OBJECTIVES

Compare HIV injecting and sex risk in patients being treated with methadone (MET) or buprenorphine-naloxone (BUP).

METHODS

Secondary analysis from a study of liver enzyme changes in patients randomized to MET or BUP who completed 24 weeks of treatment and had 4 or more blood draws. The initial 1:1 randomization was changed to 2:1 (BUP:MET) after 18 months due to higher dropout in BUP. The Risk Behavior Survey measured HIV risk before 30 days at baseline and weeks 12 and 24.

RESULTS

Among 529 patients randomized to MET, 391 (74%) were completers; among 740 randomized to BUP, 340 (46%) were completers; 700 completed the Risk Behavior Survey. There were significant reductions in injecting risk (P < 0.0008) with no differences between groups in mean number of times reported injecting heroin, speedball, other opiates, and number of injections; or percent who shared needles; did not clean shared needles with bleach; shared cookers; or engaged in front/back loading of syringes. The percent having multiple sex partners decreased equally in both groups (P < 0.03). For males on BUP, the sex risk composite increased; for males on MET, the sex risk decreased resulting in significant group differences over time (P < 0.03). For females, there was a significant reduction in sex risk (P < 0.02) with no group differences.

CONCLUSIONS

Among MET and BUP patients who remained in treatment, HIV injecting risk was equally and markedly reduced; however, MET retained more patients. Sex risk was equally and significantly reduced among females in both treatment conditions, but it increased for males on BUP and decreased for males on MET.

Ethnic and genetic factors in methadone pharmacokinetics: a population pharmacokinetic study

BACKGROUND

Treatment of opiate use disorders with methadone is complicated by wide interindividual variability in pharmacokinetics. To identify potentially contributing covariates in methadone pharmacokinetics, we used population pharmacokinetic modeling to estimate clearance (CL/F) and volume of distribution (V/F) for each methadone enantiomer in an ethnically diverse methadone maintained population.

METHODS

Plasma levels of the opiate-active R-methadone and opiate-inactive S-methadone were measured in 206 methadone maintained subjects approximately two and twenty-three hours after a daily oral dose of rac-methadone. A linear one-compartment population pharmacokinetic model with first-order conditional estimation with interaction (FOCE-I) was used to evaluate methadone CL/F and V/F. The influence of covariates on parameter estimates was evaluated using stepwise covariate modeling. Covariates included ethnicity, gender, weight, BMI, age, methadone dose, and 21 single nucleotide polymorphisms in genes implicated in methadone pharmacokinetics.

RESULTS

In the final model, for each enantiomer, Hmong ethnicity reduced CL/F by approximately 30% and the rs2032582 (ABCB1 2677G>T/A) GG genotype was associated with a 20% reduction in CL/F. The presence of the rs3745274 minor allele (CYP2B6 515G>T) reduced CL/F by up to 20% for S-methadone only. A smaller effect of age was noted on CL/F for R-methadone.

CONCLUSION

This is the first report showing the influence of the rs2032582 and rs3745274 variants on methadone pharmacokinetics rather than simply dose requirements or plasma levels. Population pharmacokinetics is a valuable method for identifying the influences on methadone pharmacokinetic variability.

Pharmacological maintenance treatments of opiate addiction

For people seeking treatment, the course of heroin addiction tends to be chronic and relapsing, and longer duration of treatment is associated with better outcomes. Heroin addiction is strongly associated with deviant behaviour and crime, and the objectives in treating heroin addiction have been a blend of humane support, rehabilitation, public health intervention and crime control. Reduction in street heroin use is the foundation on which all these outcomes are based. The pharmacological basis of maintenance treatment of dependent individuals is to minimize withdrawal symptoms and attenuate the reinforcing effects of street heroin, leading to reduction or cessation of street heroin use. Opioid maintenance treatment can be moderately effective in suppressing heroin use, although deviations from evidence-based approaches, particularly the use of suboptimal doses, have meant that treatment as delivered in practice may have resulted in poorer outcomes than predicted by research. Methadone treatment has been 'programmatic', with a one-size-fits-all approach that in part reflects the perceived need to impose discipline on deviant individuals. However, differences in pharmacokinetics and in side-effects mean that many patients do not respond optimally to methadone. Injectable diamorphine (heroin) provides a more reinforcing medication for some 'nonresponders' and can be a valuable option in the rehabilitation of demoralized, socially excluded individuals. Buprenorphine, a partial agonist, is a less reinforcing medication with different side-effects and less risk of overdose. Not only is it a different medication, but also it can be used in a different paradigm of treatment, office-based opioid treatment, with less structure and offering greater patient autonomy.

A latent class analysis of self-reported clinical indicators of psychosocial stability and adherence among opioid substitution therapy patients: do stable patients receive more unsupervised doses?

AIMS

To develop a stability typology among opioid substitution therapy patients using a range of adherence indicators derived from clinical guidelines, and determine whether stable patients receive more unsupervised doses.

METHODS

An interviewer-administered cross-sectional survey was used in opioid substitution therapy programmes in three Australian jurisdictions, totalling 768 patients in their current treatment episode for ≥4 weeks. A structured questionnaire collated data from patients about their demographics, treatment characteristics, past 6-month drug use and medication adherence, psychosocial stability, comorbidity, child welfare concerns and levels of supervised dosing. Latent class analysis (LCA) was used to derive a stability typology. Linear regression models examined predictors of unsupervised dosing in the past month.

RESULTS

LCA identified two classes: (i) a higher-adherence group (67%) who had low-moderate probabilities of endorsing the opioid substitution therapy stability indicators and (ii) a lower-adherence group (33%) who had moderate-high probabilities of endorsing the stability indicators. There was no association between adherence profile and the number of unsupervised doses. Significant predictors of receiving larger numbers of unsupervised doses included being older, living in New South Wales or South Australia (vs. Victoria), receiving methadone (vs. mono-buprenorphine), being prescribed in private clinic or general practice (vs. public clinic), reporting a longer current treatment episode, not receiving a urine drug screen in the past month, being currently employed and not having a prison history.

CONCLUSIONS

This study suggested that system-level factors and observable indicators of social functioning were more strongly associated with the receipt of less supervised treatment. Future research should examine this issue using prospectively collected data.

A call for evidence-based medical treatment of opioid dependence in the United States and Canada

Despite decades of experience treating heroin or prescription opioid dependence with methadone or buprenorphine--two forms of opioid substitution therapy--gaps remain between current practices and evidence-based standards in both Canada and the United States. This is largely because of regulatory constraints and pervasive suboptimal clinical practices. Fewer than 10 percent of all people dependent on opioids in the United States are receiving substitution treatment, although the proportion may increase with expanded health insurance coverage as a result of the Affordable Care Act. In light of the accumulated evidence, we recommend eliminating restrictions on office-based methadone prescribing in the United States; reducing financial barriers to treatment, such as varying levels of copayment in Canada and the United States; reducing reliance on less effective and potentially unsafe opioid detoxification; and evaluating and creating mechanisms to integrate emerging treatments. Taking these steps can greatly reduce the harms of opioid dependence by maximizing the individual and public health benefits of treatment.

High levels of opioid analgesic co-prescription among methadone maintenance treatment clients in British Columbia, Canada: results from a population-level retrospective cohort study

BACKGROUND AND OBJECTIVES

The non-medical use of prescription opioids (PO) has increased dramatically in North America. Special consideration for PO prescription is required for individuals in methadone maintenance treatment (MMT). Our objective is to describe the prevalence and correlates of PO use among British Columbia (BC) MMT clients from 1996 to 2007.

METHODS

This study was based on a linked, population-level medication dispensation database. All individuals receiving 30 days of continuous MMT for opioid dependence were included in the study. Key measurements included the proportion of clients receiving >7 days of a PO other than methadone during MMT from 1996 to 2007. Factors independently associated with PO co-prescription during MMT were assessed using generalized linear mixed effects regression.

RESULTS

16,248 individuals with 27,919 MMT episodes at least 30 days in duration were identified for the study period. Among them, 5,552 individuals (34.2%) received a total of 290,543 PO co-prescriptions during MMT. The majority (74.3%) of all PO dispensations >7 days originated from non-MMT physicians. The number of PO prescriptions per person-year nearly doubled between 1996 and 2006, driven by increases in morphine, hydromorphone and oxycodone dispensations. PO co-prescription was positively associated with female gender, older age, higher levels of medical co-morbidity as well as higher MMT dosage, adherence, and retention.

CONCLUSION AND SCIENTIFIC SIGNIFICANCE

A large proportion of MMT clients in BC received co-occurring PO prescriptions, often from physicians and pharmacies not delivering MMT. Experimental evidence for the treatment of pain in MMT clients is required to guide clinical practice.

Opioid-related mortality and filled prescriptions for buprenorphine and methadone

INTRODUCTION AND AIMS

To assess opioid-related mortality and correlation with filled prescriptions for buprenorphine and methadone.

DESIGN AND METHODS

A register study, including data from the Swedish Forensic Pathology and Forensic Toxicology databases 2003-2010, the Prescribed Drug Register and the National Patient Register.

RESULTS

A total of 1301 deaths, assessed as related to buprenorphine, methadone or heroin, or a combination of them, were studied. The largest number of fatalities was related to intake of heroin (n = 776), followed by methadone (n = 342) and buprenorphine (n = 168). The total annual number of fatal cases related to the studied drugs more than doubled (116 to 255) during the study period. There were increases in mortality related to both buprenorphine and methadone: from 1 to 49 cases for buprenorphine, and from 19 to 81 cases for methadone. Only one-fifth of the fatal cases had a filled prescription for the maintenance drug assessed as the cause of death.

DISCUSSION AND CONCLUSION

This study showed that most fatalities were not related to filled prescriptions of maintenance drugs, and a substantial illicit use of buprenorphine and methadone resulting in deaths was revealed. To prevent opioid toxicity deaths it is important to make efforts not only to reduce drug diversion from maintenance programs, but also to improve the control of drug trafficking and other illegal sources.

Treatment retention, drug use and social functioning outcomes in those receiving 3 months versus 1 month of supervised opioid maintenance treatment. Results from the Super C randomized controlled trial

AIM

Supervised consumption of opioid maintenance treatment (OMT) is standard in many drug centres reducing drug diversion, but is costly. We aimed to determine whether supervised consumption of OMT improved retention and other measures of drug use.

DESIGN

Pragmatic randomized controlled trial comparing 3 months of daily supervised consumption of OMT with 1 month or less of daily supervised OMT, then daily unsupervised consumption.

SETTING

Four community drug services in the United Kingdom.

PARTICIPANTS

A total of 293 opioid-dependent patients entering OMT.

PRIMARY OUTCOME

retention in treatment at 12 weeks. Secondary: retention at 6 months; illicit drug use [Maudsley Addiction Profile (MAP)]; quality of life (SF-12 and MAP); criminality (MAP); and social functioning.

FINDINGS

No significant between-group difference was observed for the primary outcome: 69% (100 of 145) supervised and 74% (109 of 148) unsupervised were retained [odds ratio (OR) = 0.74, 95% confidence interval (CI) = 0.43-1.27]. Per protocol survival analysis suggested that supervised patients were less well retained (hazard ratio for retention = 0.71, 95% CI = 0.51-1.00). Illicit opioid use reduced in both groups and, while not statistically significant by intention-to-treat analysis, favoured unsupervised patients in per protocol analysis (odds of positive opioid screen for supervised versus unsupervised = 2.07, 95% CI = 1.05-4.06). Data on criminal activity also favoured unsupervised patients with 21% supervised patients committing crime versus 9% unsupervised (OR = 3.37, 95% CI = 1.28-8.86).

CONCLUSIONS

There was no evidence of a difference in treatment retention or opioid use rates between patients whose consumption of opioid maintenance treatment was supervised for 3 months daily (except Saturdays) compared with supervision for 1 month. There was some evidence that longer periods of supervised consumption were associated with higher levels of criminality.

Prescribing controlled substances during a prescription drug epidemic

We are currently in the midst of an epidemic of deaths caused by the misuse of prescription medications. Opioids, benzodiazepines, and stimulants are among the most frequently misused controlled substances and are integral to the neurologist's armamentarium. Thus, the decision to prescribe a controlled substance and how to mitigate the associated risks of their misuse is often vexing to the clinician. This installment in the "Clinical Challenge" series provides a basic narrative overview of the epidemiology of prescription drug misuse, a summary of each of the major classes of misused drugs, and clinical recommendations regarding screening for misuse and reducing the risks associated with prescribing controlled substances.

'Diversion' of methadone or buprenorphine: 'harm' versus 'helping'

Background

'Non-compliant’ individuals in opioid maintenance treatment, OMT, are often met with tight control regimes to reduce the risk of 'diversion’, which may lead to harm or death among persons outside of OMT. This article explores reported practices of, and motivations for, diversion of methadone and buprenorphine, in a group of imprisoned individuals in OMT.

Findings

28 in-depths interviews were conducted among 12 OMT-enrolled, imprisoned individuals, most of whom were remand prisoners. All had experienced tight control regimes prior to imprisonment due to varying degrees of 'non-compliance’ and illicit drug use during treatment. Their acquired norm of sharing with others in a drug using community was maintained when entering OMT. Giving one’s prescription opioids to an individual in withdrawal was indeed seen as an act of helping, something that takes on particular significance for couples in which only one partner is included in OMT and the other is using illicit heroin. Individuals enrolled in OMT might thus be trapped between practicing norms of helping and sharing and adhering to treatment regulations. ’Diversion’, as this term is conventionally used, is not typically understood as practices of giving and helping, but may nevertheless be perceived as such by those who undertake them.

Conclusions

As we see it, the need to sustain oneself as a decent person in one’s own eyes and those of others through practices such as sharing and helping should be recognized. Treatment providers should consider including couples in which both individuals are motivated for starting OMT.

Methadone dose at the time of release from prison significantly influences retention in treatment: implications from a pilot study of HIV-infected prisoners transitioning to the community in Malaysia

OBJECTIVE

To evaluate the impact of methadone dose on post-release retention in treatment among HIV-infected prisoners initiating methadone maintenance treatment (MMT) within prison.

METHODS

Thirty HIV-infected prisoners meeting DSM-IV pre-incarceration criteria for opioid dependence were enrolled in a prison-based, pre-release MMT program in Klang Valley, Malaysia; 3 died before release from prison leaving 27 evaluable participants. Beginning 4 months before release, standardized methadone initiation and dose escalation procedures began with 5mg daily for the first week and 5mg/daily increases weekly until 80 mg/day or craving was satisfied. Participants were followed for 12 months post-release at a MMT clinic within 25 kilometers of the prison. Kaplan-Meier survival analysis was used to evaluate the impact of methadone dose on post-release retention in treatment.

FINDINGS

Methadone dose ≥80 mg/day at the time of release was significantly associated with retention in treatment. After 12 months of release, only 21.4% of participants on <80 mg were retained at 12 months compared to 61.5% of those on ≥80 mg (Log Rank χ(2)=(1,26) 7.6, p<0.01).

CONCLUSIONS

Higher doses of MMT at time of release are associated with greater retention on MMT after release to the community. Important attention should be given to monitoring and optimizing MMT doses to address cravings and side effects prior to community re-entry from prisons.

Injecting drug users in Scotland, 2006: Listing, number, demography, and opiate-related death-rates

Using Bayesian capture-recapture analysis, we estimated the number of current injecting drug users (IDUs) in Scotland in 2006 from the cross-counts of 5670 IDUs listed on four data-sources: social enquiry reports (901 IDUs listed), hospital records (953), drug treatment agencies (3504), and recent Hepatitis C virus (HCV) diagnoses (827 listed as IDU-risk). Further, we accessed exact numbers of opiate-related drugs-related deaths (DRDs) in 2006 and 2007 to improve estimation of Scotland's DRD rates per 100 current IDUs. Using all four data-sources, and model-averaging of standard hierarchical log-linear models to allow for pairwise interactions between data-sources and/or demographic classifications, Scotland had an estimated 31700 IDUs in 2006 (95% credible interval: 24900-38700); but 25000 IDUs (95% CI: 20700-35000) by excluding recent HCV diagnoses whose IDU-risk can refer to past injecting. Only in the younger age-group (15-34 years) were Scotland's opiate-related DRD rates significantly lower for females than males. Older males' opiate-related DRD rate was 1.9 (1.24-2.40) per 100 current IDUs without or 1.3 (0.94-1.64) with inclusion of recent HCV diagnoses. If, indeed, Scotland had only 25000 current IDUs in 2006, with only 8200 of them aged 35+ years, the opiate-related DRD rate is higher among this older age group than has been appreciated hitherto. There is counter-balancing good news for the public health: the hitherto sharp increase in older current IDUs had stalled by 2006.

A record-linkage study of drug-related death and suicide after hospital discharge among drug-treatment clients in Scotland, 1996-2006

AIMS

To investigate the relationship between time after hospital discharge and drug-related death (DRD) and suicide among drug users in Scotland, while controlling for potential confounders.

DESIGN

Cohort study.

SETTING AND PARTICIPANTS

The 69 457 individuals who registered for drug treatment in Scotland during 1 April 1996-31 March 2006.

MEASUREMENTS

Time-at-risk was from the date of an individual's first attendance at drug treatment services after 1 April 1996 until the earlier date of death or end-of-study, 31 March 2006, and was categorized according to time since the most recent hospitalization, as during hospitalization, within 28 days, 29-90 days, 91 days to 1 year and >1 year since discharge from most recent hospital stay versus 'never admitted' (reference).

FINDINGS

Time-periods soon after discharge were associated with increased risk of DRD. DRD rates per 1000 person-years were: 87 (95% CI: 72-103) during hospitalization, 21 (18-25) within 28 days, 12 (10-15) during 29-90 days and 8.5 (7.5-9.5) during 91 days to 1 year after discharge versus 4.2 (3.7-4.7) when >1 year after most recent hospitalization and 1.9 (1.7-2.1) for those never admitted. Adjusted hazard ratios by time since hospital discharge (versus never admitted) were: 9.6 (95% CI: 8-12) within 28 days, 5.6 (4.6-6.8) during days 29-90, thereafter 4.0 (3.5-4.7) and 2.3 (2.0-2.7) when >1 year. Non-drug-related suicides were less frequent than DRDs (269 versus 1383) but a similar risk pattern was observed.

CONCLUSIONS

In people receiving treatment for drug dependence, discharge from a period of hospitalization marks the start of a period of heightened vulnerability to drug-related death.

Methadone-related deaths in Norway

INTRODUCTION

The use of methadone in opioid maintenance treatment (OMT) is potentially associated with a number of adverse effects and the risk of fatal toxicity. Increased methadone availability may lead to an increase in methadone-related deaths. We have investigated methadone-related deaths in Norway over the period 2000-2006.

MATERIALS AND METHODS

Methadone-positive samples over the period 2000-2006 were identified from forensic toxicological investigations, and demographic and toxicological data were retrieved. The cases were cross-linked with the Norwegian Cause of Death Registry and regional OMT registers.

RESULTS

A total of 312 individuals had died after taking methadone over the period 2000-2006, predominantly men with a mean age of 36. In 85% of cases (n=264), the deceased had died of a methadone-related intoxication, most often in combination with other drugs, including benzodiazepines, cannabis and other opioids. Only 22% of the deceased had been in OMT at the time of death. A larger proportion of OMT patients had died of causes other than intoxications compared to those not in OMT (30% vs. 8%, respectively), most commonly related to disease.

CONCLUSIONS

One methadone-related death occurred, on average, every week over the time period investigated. Only 22% of the deceased were registered in opioid maintenance treatment (OMT) programs. The findings underline the need to control diversion of medication from OMT programs.

New systems of care for substance use disorders: treatment, finance, and technology under health care reform

This article outlined ways in which persons with addiction are currently underserved by our current health care system. However, with the coming broad scale reforms to our health care system, the access to and availability of high-quality care for substance use disorders will increase. Addiction treatments will continue to be offered through traditional substance abuse care systems, but these will be more integrated with primary care, and less separated as treatment facilities leverage opportunities to blend services, financing mechanisms, and health information systems under federally driven incentive programs. To further these reforms, vigilance will be needed by consumers, clinicians, and policy makers to assure that the unmet treatment needs of individuals with addiction are addressed. Embedded in this article are essential recommendations to facilitate the improvement of care for substance use disorders under health care reform. Ultimately, as addiction care acquires more of the “look and feel” of mainstream medicine, it is important to be mindful of preexisting trends in health care delivery overall that are reflected in recent health reform legislation. Within the world of addiction care, clinicians must move beyond their self-imposed “stigmatization” and sequestration of specialty addiction treatment. The problem for addiction care, as it becomes more “mainstream,” is to not comfortably feel that general slogans like “Treatment Works,” as promoted by Substance Abuse and Mental Health Services Administration’s Center for Substance Abuse Treatment during its annual Recovery Month celebrations, will meet the expectations of stakeholders outside the specialty addiction treatment community. Rather, the problem is to show exactly how addiction treatment works, and to what extent it works-there have to be metrics showing changes in symptom level or functional outcome, changes in health care utilization, improvements in workplace attendance and productivity, or other measures. At minimum, clinicians will be required to demonstrate that their new systems of care and future clinical activity are in conformance with overall standards of “best practice” in health care.

The nature of methadone diversion in England: a Merseyside case study

Background

Methadone maintenance treatment (MMT) is a key element in treatment for opiate addiction; however concerns about the diversion of methadone remain. More current empirical data on methadone diversion are required. This research investigated the market for diverted methadone in Merseyside, UK, in order to provide a case study which can be transferred to other areas undertaking methadone maintenance treatment on a large scale.

Methods

Questionnaires were completed (in interview format) with 886 past year users of methadone recruited both in and out of prescribing agencies. Topic areas covered included current prescribing, obtaining and providing methadone, reasons for using illicit methadone and other drug use.

Results

Large proportions of participants had obtained illicit methadone for use in the past year with smaller proportions doing so in the past month. Proportions of participants buying and being given methadone were similar. Exchange of methadone primarily took place between friends and associates, with 'dealers' rarely involved. Gender, age, whether participant's methadone consumption was supervised and whether the aims of their treatment had been explained to them fully, influenced the extent to which participants were involved in diverting or using diverted methadone.

Conclusion

Methadone diversion is widespread although drug users generally do not make use of illicit methadone regularly (every month). The degree of altruism involved in the exchange of methadone does not negate the potential role of this action in overdose or the possibility of criminal justice action against individuals. Treatment agencies need to emphasise these risks whilst ensuring that treatment aims are effectively shared with clients to ensure adherence to treatment.

Drug policy and the public good: evidence for effective interventions

Debates about which policy initiatives can prevent or reduce the damage that illicit drugs cause to the public good are rarely informed by scientific evidence. Fortunately, evidence-based interventions are increasingly being identified that are capable of making drugs less available, reducing violence in drug markets, lessening misuse of legal pharmaceuticals, preventing drug use initiation in young people, and reducing drug use and its consequences in established drug users. We review relevant evidence and outline the likely effects of fuller implementation of existing interventions. The reasoning behind the final decisions for action might be of a non-scientific nature, focused more on what the public and policy-makers deem of value. Nevertheless, important opportunities exist for science to inform these deliberations and guide the selection of policies that maximise the public good.

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.

A pilot randomised controlled trial of brief versus twice weekly versus standard supervised consumption in patients on opiate maintenance treatment

INTRODUCTION AND AIMS

Methadone maintenance remains the mainstay of treatment for opiate dependence in Scotland. Guidelines recommend supervised self-administration for at least 3 months, yet this is often interpreted as long-term supervision. However, there is no evidence base for deciding the optimal period of supervision. We tested the feasibility of conducting a randomised controlled trial (RCT) of different supervision models.

DESIGN AND METHODS

Three armed pilot RCT, set in three Scottish treatment areas, recruited opiate-dependent patients who had received methadone treatment for 3 months. Participants were randomised to: (i) no supervision; (ii) twice weekly supervision; or (iii) daily supervision for further 3 months. As a pilot, key process measures were: recruitment rates, follow-up rates and treatment fidelity. We also wanted to estimate effect sizes of two co-primary outcomes for a full RCT: treatment retention and illicit heroin use. The recruitment target was 60 participants.

RESULTS

One hundred and two eligible patients were identified, 60 (59%) participated, and 46 followed up (77%). Study fidelity was good with two participants moving group. Those randomised to no supervision were significantly happier with their group allocation. No significant differences were found in primary outcomes, although retention decreased with increased supervision, while illicit heroin use was least in those most supervised.

DISCUSSION AND CONCLUSIONS

It is possible to recruit and randomise participants to an RCT comparing different forms of supervised consumption. Pilot data suggest increased supervision may reduce illicit heroin use, but may decrease retention. This should now be tested in a large-scale multicentre RCT.

The impact of needle and syringe provision and opiate substitution therapy on the incidence of hepatitis C virus in injecting drug users: pooling of UK evidence

AIMS

To investigate whether opiate substitution therapy (OST) and needle and syringe programmes (NSP) can reduce hepatitis C virus (HCV) transmission among injecting drug users (IDUs).

DESIGN

Meta-analysis and pooled analysis, with logistic regression allowing adjustment for gender, injecting duration, crack injecting and homelessness.

SETTING

Six UK sites (Birmingham, Bristol, Glasgow, Leeds, London and Wales), community recruitment.

PARTICIPANTS

A total of 2986 IDUs surveyed during 2001-09.

MEASUREMENT

Questionnaire responses were used to define intervention categories for OST (on OST or not) and high NSP coverage (≥100% versus <100% needles per injection). The primary outcome was new HCV infection, measured as antibody seroconversion at follow-up or HCV antibody-negative/RNA-positive result in cross-sectional surveys.

FINDINGS

Preliminary meta-analysis showed little evidence of heterogeneity between the studies on the effects of OST (I2=48%, P=0.09) and NSP (I2=0%, P=0.75), allowing data pooling. The analysis of both interventions included 919 subjects with 40 new HCV infections. Both receiving OST and high NSP coverage were associated with a reduction in new HCV infection [adjusted odds ratios (AORs)=0.41, 95% confidence interval (CI): 0.21-0.82 and 0.48, 95% CI: 0.25-0.93, respectively]. Full harm reduction (on OST plus high NSP coverage) reduced the odds of new HCV infection by nearly 80% (AOR=0.21, 95% CI: 0.08-0.52). Full harm reduction was associated with a reduction in self-reported needle sharing by 48% (AOR 0.52, 95% CI: 0.32-0.83) and mean injecting frequency by 20.8 injections per month (95% CI: -27.3 to -14.4).

CONCLUSIONS

There is good evidence that uptake of opiate substitution therapy and high coverage of needle and syringe programmes can substantially reduce the risk of hepatitis C virus transmission among injecting drug users. Research is now required on whether the scaling-up of intervention exposure can reduce and limit hepatitis C virus prevalence in this population.