Association between availability of heroin and methadone and fatal poisoning in England and Wales 1993–2004

Bridging the Macro-micro Divide: A Qualitative Meta-synthesis on the Perspectives and Experiences of Health Care Providers on the Extramedical Use and Diversion of Buprenorphine

OBJECTIVES

Opioid agonist therapy using buprenorphine is one of the most effective treatments for opioid use disorder. However, concerns regarding its extramedical use and diversion, such as adverse patient outcomes and damage to the legitimacy of addictions practice, are persistent. The aim of this review is to synthesize the perspectives and experiences of health care providers around the extramedical use of buprenorphine.

METHODS

A qualitative meta-synthesis was conducted based on a systematic search of 8 databases. All primary qualitative and mixed-methods studies relating to the views of health care providers on the extramedical use of buprenorphine were included. A qualitative analysis informed by the constant comparative method was conducted, using NVivo for data management.

RESULTS

Sixteen studies were included in this review. Findings were organizedunder 2 key themes: (1) Harm-producing versus harm-reducing effects of extramedical buprenorphine use and (2) driving forces of and responses to extramedical buprenorphine use.

CONCLUSIONS

The studies included in our review identified a disconnect-health care providers noted that macro, health care system-level challenges drove extramedical use whereas the recommended solutions for prevention and management were primarily aimed at the micro, individual level. This study emphasizes the critical role that health care providers can play, in partnership with patients, in informing appropriate policies and health care system design to optimize the care for people with opioid use disorder.

Non-prescribed use of methadone and buprenorphine prior to opioid substitution treatment: lifetime prevalence, motives, and drug sources among people with opioid dependence in five Swedish cities

BACKGROUND

Opioid substitution treatment (OST) with methadone or buprenorphine is the most effective means of treating opioid dependence. If these substances are used by people who are not undergoing OST, they can however carry serious risks. This article examines the lifetime prevalence, motives, and drug sources for such use, as well as geographical differences in these variables.

METHODS

Structured interviews were conducted with 411 patients from 11 OST clinics in five Swedish cities. The researchers carried out 280 interviews on-site, while 131 interviews were conducted by specially trained patients through privileged access interviewing. Data were analyzed by frequency and average calculations, cross-tabulations, and χ2 tests.

RESULTS

The lifetime prevalence of non-prescribed use was 87.8% for methadone, 80.5% for buprenorphine, and 50.6% for buprenorphine/naloxone. Pseudo-therapeutic motives-avoiding withdrawal symptoms, staying clean from heroin, detoxification, or taking care of one's own OST-were commonly cited as driving the use, while using the drugs for euphoric purposes was a less common motive. Most respondents had bought or received the substances from patients in OST, but dealers were also a significant source of non-prescribed methadone and buprenorphine. Geographical differences of use, motives, and sources suggest that prescription practices in OST have a great impact on which substances are used outside of the treatment.

CONCLUSIONS

Experiences of non-prescribed use of methadone and buprenorphine are extremely common among those in OST in southern Sweden. As the use is typically driven by pseudo-therapeutic motives, increased access to OST might decrease the illicit demand for these substances. Buprenorphine/naloxone has a lower abuse potential than buprenorphine and should therefore be prioritized as the prescribed drug. Supervised dosage and other control measures are important provisions in the prevention of drug diversion and non-prescribed use among people not undergoing OST.

Methadone's effects on pentylenetetrazole-induced seizure threshold in mice: NMDA/opioid receptors and nitric oxide signaling

Methadone is a synthetic opioid used to treat opiate withdrawal and addiction. Studies have demonstrated the impact of methadone on seizure susceptibility. This study investigated the modulatory impacts of acute and subchronic (three times daily for 5 days) intraperitoneal methadone treatment on pentylenetetrazole-induced clonic seizure threshold (CST) in mice, as well as the involvement of the nitric oxide, N-methyl-d-aspartate (NMDA), and µ-opioid pathways. Acute administration of different doses of methadone (0.1, 0.3, 1, and 3 mg/kg) 45 min before CST significantly decreased the seizure threshold. Additionally, pretreatment with noneffective doses of an opioid receptor antagonist (naltrexone) and NMDA receptor antagonists (ketamine and MK-801) inhibited methadone's proconvulsive activity in the acute phase, while l-NAME (a nonspecific nitric oxide synthase (NOS) inhibitor) did not affect that activity. In the subchronic phase, methadone (3 mg/kg) demonstrated an anticonvulsive effect. Although subchronic pretreatment with noneffective doses of l-NAME and 7-nitroindazole (a specific neuronal NOS inhibitor) reversed methadone's anticonvulsive activity, aminoguanidine (a specific inducible NOS inhibitor), naltrexone, MK-801, and ketamine did not change methadone's anticonvulsive characteristic. Our results suggest that NMDA and µ-opioid receptors may be involved in methadone's proconvulsive activity in the acute phase, while methadone's anticonvulsive activity may be modulated by neuronal NOS in the subchronic phase.

The impact of opiate substitution treatment on mortality risk in drug addicts: a natural experiment study

Background

Opiate substitution treatment (OST) is the main treatment for people addicted to heroin and other opioid drugs. However, there is limited information on how the delivery of this treatment affects mortality risk.

Objectives

To investigate the associations of mortality risk with periods during treatment and following cessation of treatment, medication type, co-prescription of other medication and dosing regimens during titration and detoxification. The trends with time of prescribed medication, dose and treatment duration were also explored.

Design

Prospective longitudinal observational study.

Setting

UK primary care between 1998 and 2014.

Participants

A total of 12,780 patients receiving methadone, buprenorphine or dihydrocodeine.

Main outcome measures

All-cause mortality relating to 657 deaths and drug-related poisoning relating to 113 deaths.

Data sources

Clinical Practice Research Datalink with linked information on cause of death from the Office for National Statistics.

Results

For both outcomes, the lowest mortality risk was observed after 4 weeks of treatment and the highest risk was observed in the first 4 weeks following cessation of treatment [e.g. for drug-related poisoning, incidence rate ratio (IRR) 8.15, 95% confidence interval (CI) 5.45 to 12.19]. There was evidence that the treatment period risks varied with OST medication. The largest difference in risk was for the first 4 weeks of treatment for both outcomes, with patients on buprenorphine being at lower risk than those on methadone (e.g. for drug-related poisoning, IRR 0.08, 95% CI 0.01 to 0.48). The co-prescription of benzodiazepines was associated with linearly increasing the risk of drug-related deaths by dose (IRR 2.02, 95% CI 1.66 to 2.47), whereas z-drugs (zolpidem, zopiclone and zaleplon) were associated with increased risk of both all-cause (IRR 1.83, 95% CI 1.59 to 2.12) and drug-related (IRR 3.31, 95% CI 2.45 to 4.47) mortality. There was weak evidence that higher initial and final doses were associated with increased all-cause mortality risk. In the first 4 weeks of treatment, the risk increased by 4% for each 5-mg increment in methadone dose (1-mg increase in buprenorphine) (hazard ratio 1.04, 95% CI 1.00 to 1.09). In the first 4 weeks after treatment ceased, a similar increment in final dose increased the risk by 3% (hazard ratio 1.03, 95% CI 0.99 to 1.07). There were too few deaths to evaluate the effects on drug-related poisoning. The proportion of OST patients receiving buprenorphine increased between 1998 and 2006. Median treatment duration was consistently shorter for buprenorphine than for methadone for each year studied (overall median duration of 48 and 106 days, respectively).

Limitations

As this was an observational study, the possibility remains of bias from unmeasured factors, which covariate adjustment and inverse probability weighting can eliminate only partially.

Conclusions

Using buprenorphine as an alternative to methadone may not reduce mortality overall despite resulting in lower IRRs from shorter treatment duration. Clinical guidance needs to consider strengthening warnings about the co-prescription of a range of drugs for OST patients.

Future work

Our analyses need to be replicated using other clinical data sets in the UK and in other countries. New interventions and trials are required to investigate improving the retention of OST patients in primary care.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Delay-Dependent Impairments in Memory and Motor Functions After Acute Methadone Overdose in Rats

Methadone is used as a substitution drug for the treatment of opioid dependence and chronic pain. Despite its widespread use and availability, there is a serious concern with respect to the relative safety of methadone. The purpose of this study was to characterize how acute methadone overdose affects the cognitive and motor performance of naïve healthy rats. The methadone overdose was induced by administering an acute toxic dose of methadone (15 mg/kg; ip; the equivalent dose of 80% of LD50) to adolescent rats. Resuscitation using a ventilator pump along with a single dose of naloxone (2 mg/kg; ip) was administered following the occurrence of apnea. The animals which were successfully resuscitated divided randomly into three apnea groups that evaluated either on day 1, 5, or 10 post-resuscitation (M/N-Day 1, M/N-Day 5, and M/N-Day 10 groups) in the Y-maze and novel object memory recognition tasks as well as pole and rotarod tests. The data revealed that a single toxic dose of methadone had an adverse effect on spontaneous behavior. In addition, Recognition memory impairment was observed in the M/N-Day 1, 5, and 10 groups after methadone-induced apnea. Further, descending time in the M/N-Day 5 group increased significantly in comparison with its respective Saline control group. The overall results indicate that acute methadone-overdose-induced apnea produced delay-dependent cognitive and motor impairment. We suggest that methadone poisoning should be considered as a possible cause of delayed neurological disorders, which might be transient, in some types of memory or motor performance in naïve healthy rats.

Increasing diversion of methadone in Vancouver, Canada, 2005-2015

BACKGROUND AND AIM

Although methadone, an opioid agonist, has been an effective medication used to treat opioid use disorder for over 40years, recent studies have found that methadone was identified in more than a quarter of prescription opioid-related deaths among people who use illicit drugs in Vancouver, Canada. Thus, we sought to longitudinally examine the availability of diverted methadone among people who inject drugs (PWID).

DESIGN AND METHODS

Data were collected from three prospective cohorts of PWID in Vancouver, Canada between December 2005 and May 2015. Multivariable generalized estimating equation logistic regression was used to identify temporal trends in the immediate availability of diverted methadone (defined as the ability to acquire illicit methadone in <10min).

RESULTS

A total of 2092 participants, including 727 (34.8%) women, were included in the present study. In the multivariable analyses after adjusting for a range of potential confounders, later calendar year (adjusted odds ratio [AOR]=1.21 per year; 95% confidence interval [CI]: 1.19-1.23) was independently and positively associated with reporting immediate availability of diverted methadone.

CONCLUSIONS

We observed a significant increase in the reported availability of diverted methadone among PWID over a ten-year follow-up period. Further research is needed to identify strategies to limit methadone diversion and assess the impact of alternative medications that are equally effective but safer, such as buprenorphine/naloxone.

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.

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.

The relationship between US heroin market dynamics and heroin-related overdose, 1992-2008

BACKGROUND AND AIMS

Heroin-related overdose is linked to polydrug use, changes in physiological tolerance and social factors. Individual risk can also be influenced by the structural risk environment including the illicit drug market. We hypothesized that components of the US illicit drug market, specifically heroin source/type, price and purity, will have independent effects on the number of heroin-related overdose hospital admissions.

METHODS

Yearly, from 1992 to 2008, Metropolitan Statistical Area (MSA) price and purity series were estimated from the US Drug Enforcement Administration data. Yearly heroin overdose hospitalizations were constructed from the Nationwide Inpatient Sample. Socio-demographic variables were constructed using several databases. Negative binomial models were used to estimate the effect of price, purity and source region of heroin on yearly hospital counts of heroin overdoses controlling for poverty, unemployment, crime, MSA socio-demographic characteristics and population size.

RESULTS

Purity was not associated with heroin overdose, but each $100 decrease in the price per pure gram of heroin resulted in a 2.9% [95% confidence interval (CI) = 4.8%, 1.0%] increase in the number of heroin overdose hospitalizations (P = 0.003). Each 10% increase in the market share of Colombian-sourced heroin was associated with a 4.1% (95% CI = 1.7%, 6.6%) increase in number of overdoses reported in hospitals (P = 0.001) independent of heroin quality.

CONCLUSIONS

Decreases in the price of pure heroin in the United States are associated with increased heroin-related overdose hospital admissions. Increases in market concentration of Colombian-source/type heroin is also associated with an increase in heroin-related overdose hospital admissions. Increases in US heroin-related overdose admissions appear to be related to structural changes in the US heroin market.

Using textual cause-of-death data to study drug poisoning deaths

Death certificate data are often used to study the epidemiology of poisoning deaths, but the International Classification of Diseases (ICD) codes used to tabulate death data do not convey all of the available information about the drugs and other substances named on death certificates. In the United States and some other countries, the SuperMICAR computer system is used to assign ICD codes to deaths. The SuperMICAR system also stores a verbatim record of the text entered for the cause of death. We used the SuperMICAR text entries to study the 7,817 poisoning deaths that occurred among Washington State residents between 2003 and 2010. We tabulated the drugs named on death certificates and computed age-adjusted and age-specific death rates for the top-named drugs and for prescription and illicit drugs. Methadone was named on 2,149 death certificates and was the most frequently named substance, followed by alcohol, opiate, cocaine, oxycodone, and methamphetamine. For both men and women and at all ages, prescription drugs were involved in more deaths than were illicit drugs. Among the 25 drugs named most frequently, only 4 have unique ICD codes; the other 21 can be identified only by using the SuperMICAR data.

Trends in the population prevalence of people who inject drugs in US metropolitan areas 1992-2007

BACKGROUND

People who inject drugs (PWID) have increased risk of morbidity and mortality. We update and present estimates and trends of the prevalence of current PWID and PWID subpopulations in 96 US metropolitan statistical areas (MSAs) for 1992-2007. Current estimates of PWID and PWID subpopulations will help target services and help to understand long-term health trends among PWID populations.

METHODOLOGY

We calculated the number of PWID in the US annually from 1992-2007 and apportioned estimates to MSAs using multiplier methods. We used four types of data indicating drug injection to allocate national annual totals to MSAs, creating four distinct series of component estimates of PWID in each MSA and year. The four component estimates are averaged to create the best estimate of PWID for each MSA and year. We estimated PWID prevalence rates for three subpopulations defined by gender, age, and race/ethnicity. We evaluated trends using multi-level polynomial models.

RESULTS

PWID per 10,000 persons aged 15-64 years varied across MSAs from 31 to 345 in 1992 (median 104.4) to 34 to 324 in 2007 (median 91.5). Trend analysis indicates that this rate declined during the early period and then was relatively stable in 2002-2007. Overall prevalence rates for non-Hispanic black PWID increased in 2005 as compared to other racial/ethnic groups. Hispanic prevalence, in contrast, declined across time. Importantly, results show a worrisome trend in young PWID prevalence since HAART was initiated--the mean prevalence was 90 to 100 per 10,000 youth in 1992-1996, but increased to >120 PWID per 10,000 youth in 2006-2007.

CONCLUSIONS

Overall, PWID rates remained constant since 2002, but increased for two subpopulations: non-Hispanic black PWID and young PWID. Estimates of PWID are important for planning and evaluating public health programs to reduce harm among PWID and for understanding related trends in social and health outcomes.

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.

Risk of drug-related mortality during periods of transition in methadone maintenance treatment: a cohort study

This study aims to identify periods of elevated risk of drug-related mortality during methadone maintenance treatment (MMT) in primary care using a cohort of 3,162 Scottish drug users between January 1993 and February 2004. Deaths occurring during treatment or within 3 days after last methadone prescription expired were considered as cases "on treatment." Fatalities occurring 4 days or more after leaving treatment were cases "off treatment." Sixty-four drug-related deaths were identified. The greatest risk of drug-related death was in the first 2 weeks of treatment (adjusted hazard ratio 2.60, 95% confidence interval 1.03-6.56). Risk of drug-related death was lower after the first 30 days following treatment cessation, relative to the first 30 days off treatment. History of psychiatric admission was associated with increased risk of drug-related death in treatment. Increasing numbers of treatment episodes and urine testing were protective. History of psychiatric admission, increasing numbers of urine tests, and coprescriptions of benzodiazepines increased the risk of mortality out of treatment. The risk of drug-related mortality in MMT is elevated during periods of treatment transition, specifically treatment initiation and the first 30 days following treatment dropout or discharge.

Risk of death during and after opiate substitution treatment in primary care: prospective observational study in UK General Practice Research Database

OBJECTIVE

To investigate the effect of opiate substitution treatment at the beginning and end of treatment and according to duration of treatment.

DESIGN

Prospective cohort study. Setting UK General Practice Research Database.

PARTICIPANTS

Primary care patients with a diagnosis of substance misuse prescribed methadone or buprenorphine during 1990-2005. 5577 patients with 267 003 prescriptions for opiate substitution treatment followed-up (17 732 years) until one year after the expiry of their last prescription, the date of death before this time had elapsed, or the date of transfer away from the practice.

MAIN OUTCOME MEASURES

Mortality rates and rate ratios comparing periods in and out of treatment adjusted for sex, age, calendar year, and comorbidity; standardised mortality ratios comparing opiate users' mortality with general population mortality rates.

RESULTS

Crude mortality rates were 0.7 per 100 person years on opiate substitution treatment and 1.3 per 100 person years off treatment; standardised mortality ratios were 5.3 (95% confidence interval 4.0 to 6.8) on treatment and 10.9 (9.0 to 13.1) off treatment. Men using opiates had approximately twice the risk of death of women (morality rate ratio 2.0, 1.4 to 2.9). In the first two weeks of opiate substitution treatment the crude mortality rate was 1.7 per 100 person years: 3.1 (1.5 to 6.6) times higher (after adjustment for sex, age group, calendar period, and comorbidity) than the rate during the rest of time on treatment. The crude mortality rate was 4.8 per 100 person years in weeks 1-2 after treatment stopped, 4.3 in weeks 3-4, and 0.95 during the rest of time off treatment: 9 (5.4 to 14.9), 8 (4.7 to 13.7), and 1.9 (1.3 to 2.8) times higher than the baseline risk of mortality during treatment. Opiate substitution treatment has a greater than 85% chance of reducing overall mortality among opiate users if the average duration approaches or exceeds 12 months.

CONCLUSIONS

Clinicians and patients should be aware of the increased mortality risk at the start of opiate substitution treatment and immediately after stopping treatment. Further research is needed to investigate the effect of average duration of opiate substitution treatment on drug related mortality.

Persistence of low drug treatment coverage for injection drug users in large US metropolitan areas

OBJECTIVES

Injection drug users (IDUs) are at high risk for HIV, hepatitis, overdose and other harms. Greater drug treatment availability has been shown to reduce these harms among IDUs. Yet, little is known about changes in drug treatment availability for IDUs in the U.S. This paper investigates change in drug treatment coverage for IDUs in 90 metropolitan statistical areas (MSAs) during 1993-2002.

METHODS

We define treatment coverage as the percent of IDUs who are in treatment. The number of IDUs in drug treatment is calculated from treatment entry data and treatment census data acquired from the Substance Abuse and Mental Health Service Administration, divided by our estimated number of IDUs in each MSA.

RESULTS

Treatment coverage was low in 1993 (mean 6.7%; median 6.0%) and only increased to a mean of 8.3% and median of 8.0% coverage in 2002.

CONCLUSIONS

Although some MSAs experienced increases in treatment coverage over time, overall levels of coverage were low. The persistence of low drug treatment coverage for IDUs represents a failure by the U.S. health care system to prevent avoidable harms and unnecessary deaths in this population. Policy makers should expand drug treatment for IDUs to reduce blood-borne infections and community harms associated with untreated injection drug use.

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

OBJECTIVE

To evaluate the impact of introduction of supervision of methadone dosing on deaths related to overdose of methadone in Scotland and England between 1993 and 2008 while controlling for increased prescribing of methadone.

DESIGN

Analysis of annual trends in deaths related to overdose of methadone in relation to defined daily doses of methadone prescribed.

SETTING

Scotland and England. Population Deaths in which methadone was coded as the only drug involved or as one of the drugs implicated.

MAIN OUTCOME MEASURE

Annual OD4-methadone index (number of deaths with methadone implicated per million defined daily doses of methadone prescribed in that year).

RESULTS

OD4-methadone declined substantially over the four epochs of four years between 1993 and 2008. It decreased significantly (P<0.05) in 10 of 12 epoch changes: in Scotland from 19.3 (95% confidence interval 15 to 24) to 4.1 (2.8 to 5.4) and finally to 3.0 (2.4 to 3.5) for methadone only deaths (and from 58 to 29 to 14 for deaths with any mention of methadone); in England from 27.1 (25 to 29) to 24.8 (23 to 27) and finally to 5.8 (5.3 to 6.3) for methadone only deaths (and from 46 to 42 to 12 for deaths with any mention of methadone). The decreases in OD4-methadone were closely related to the introduction of supervised dosing of methadone in both countries, first in Scotland (1995-2000) and later in England (1999-2005). These declines occurred over periods of substantial increases in prescribing of methadone (18-fold increase in defined daily doses per million population annually in Scotland and sevenfold increase in England).

CONCLUSIONS

Introduction of supervised methadone dosing was followed by substantial declines in deaths related to overdose of methadone in both Scotland and England. OD4-methadone index analyses, controlled for substantial increases in methadone prescribing in both countries, identified at least a fourfold reduction in deaths due to methadone related overdose per defined daily dose (OD4-methadone) over this period.

The global diversion of pharmaceutical drugs: opiate treatment and the diversion of pharmaceutical opiates: a clinician's perspective

AIM

To provide a clinician's perspective on the problem of diversion of prescribed pharmaceuticals.

METHODS

The paper provides a personal account of working in a treatment context where diversion from opioid substitution treatment (OST) became a political issue potentially compromising the continued delivery of OST. It summarizes evidence on the impact of diversion, and measures to contain it, from the United Kingdom 1986-2006, Australia 1996-2008 and the United States and France from the mid-1990s.

RESULTS

Opioid diversion to the black market occurs in proportion to the amount of opioids prescribed to be taken without supervision, and in inverse proportion to the availability of heroin. Diversion for OST programmes using supervision of dosing is less than diversion of opioids prescribed for pain, which is now a growing public health problem. Adverse consequences of diversion include opioid overdose fatalities, an increased incidence of addiction (particularly in jurisdictions where heroin is scarce) and compromising the public acceptance of long-term opioid prescribing. All long-term opioid prescribing requires monitoring of risk and appropriate dispensing arrangements--including dilution of methadone take-aways, supervision of administration for high-risk patients and random urine testing. Clinical guidelines influence practice, although prescribing often deviates from guidelines.

CONCLUSION

Clinical guidelines and clinical audit to enhance compliance with guidelines are helpful in maintaining the quality and integrity of the treatment system, and can contribute to keeping diversion within acceptable levels.

Drug poisoning deaths in Sweden show a predominance of ethanol in mono-intoxications, adverse drug-alcohol interactions and poly-drug use

Over a 10-year period (1998-2007) all deaths in Sweden classified by forensic pathologists as fatal drug poisonings (N = 6894) were retrieved from a toxicology database (TOXBASE) belonging to the National Board of Forensic Medicine. The deaths were further classified as suicides N = 2288 (33%), undetermined N = 2260 (33%) and accidental N = 2346 (34%). The average age (± SD) of all victims was 49.1 ± 15.9 years and men 47.4 ± 15.6 years were 5-year younger than women 52.2 ± 15.8 years (p < 0.01). Most of the deceased (78%) were poly-drug users although a single drug (mono-intoxications) was found in 22% of all poisoning deaths (p < 0.001). The number of drugs in blood samples varied from 1 to 12 with a median of 3-4 per case. Mono-intoxication deaths were mostly ethanol-related (N = 976) and the mean and median blood-alcohol concentration (BAC) was 3.06 g/L and 3.10 g/L, respectively. The BAC decreased as the number of additional drugs in blood increased from 2.15 g/L with one drug to 1.25 g/L with 6 or more drugs. The mean (median) concentrations of non-alcohol drugs in mono-intoxication deaths were morphine (N = 93) 0.5mg/L (0.2mg/L), amphetamine (N = 39) 2.0mg/L (1.2mg/L), dextropropoxyphene (N = 33) 3.9 mg/L (2.9 mg/L), dihydro-propiomazine (N = 32) 1.6 mg/L (1.0mg/L) and 7-amino-flunitrazepam (N = 28), 0.4 mg/L (0.3mg/L). Elevated blood morphine in these poisoning deaths mostly reflected abuse of heroin as verified by finding 6-monoacetyl morphine (6-MAM) in the blood samples. When investigating drug poisoning deaths a comprehensive toxicological analysis is essential although the results do not reveal the extent of prior exposure to drugs or the development of pharmacological tolerance. The concentrations of drugs determined in post-mortem blood are one element in the case. The autopsy report, the police investigation, the findings at the scene and eye-witness statements should all be carefully considered when the cause and manner of death are determined.

Hepatitis C infection among injecting drug users in England and Wales (1992-2006): there and back again?

Changes in hepatitis C virus (HCV) prevalence from 1992 to 2006 were examined by using 24,311 records from unlinked anonymous surveillance of injecting drug users in England and Wales. Bayesian logistic regression was used to estimate annual prevalence, accounting for changing recruitment patterns (age, gender, injecting duration, geographic region, interactions) and the sensitivity and specificity of different oral fluid testing devices. After controlling for these differences, the authors found that the adjusted HCV prevalence decreased from 70% (95% credible interval: 62, 78) in 1992 to 47% (95% credible interval: 43, 51) in 1998 before rising again to 53% (95% credible interval: 48, 58) in 2006. Women injecting drug users had a higher HCV risk than did men (odds ratio = 1.50, 95% credible interval: 1.31, 1.73). Two regions (London and North West) had a markedly higher HCV prevalence than did the rest of England and Wales. Among individuals who had injected for less than 1 year, the adjusted HCV prevalence in 2006 was higher than that in 1992 (28% vs. 19%, respectively). HCV infection can be prevented. The public health challenge in England and Wales is to increase action in order to regain a downward trend in HCV risk and the benefit that has been lost since 1998.

Assessing IDU prevalence and health consequences (HCV, overdose and drug-related mortality) in a primary care trust: implications for public health action

BACKGROUND

We report on an exercise to estimate the prevalence of injecting drug use (IDU) and associated harms in a single primary care trust.

METHODS

Covariate capture-recapture methods to estimate (i) IDU prevalence; respondent driven sampling to measure (ii) prevalence of HCV and HIV and record linkage to measure (iii) mortality risk.

RESULTS

(i) The overall estimated number of IDU was 5540 (95% confidence interval, CI: 4710-6780) for all cases and 3280 (95% CI: 1940-4610) for cases matched to primary care register, i.e. a prevalence of 2.2 and 1.3% aged 15-54, respectively. (ii) The prevalence of HCV, hepatitis B and HIV was: 53, 32 and 0.7%. Over 70% of IDU in Bristol reported having at least one vaccination for HBV; more than half of those who were HCV positive were undiagnosed. (iii) The all-cause and overdose mortality rates for IDU were 0.75 and 0.4% respectively; and the standardized mortality ratio was 7.8 (95% CI: 5.4-10.8).

CONCLUSION

Locally specific and useful intelligence on injecting and its health consequence can be generated to inform local public health action, and may contribute information to validate national prevalence estimates.

Factors associated with mortality in Scottish patients receiving methadone in primary care: retrospective cohort study

OBJECTIVE

To assess predictors of mortality in a population of people prescribed methadone.

DESIGN

Retrospective cohort study.

SETTING

Geographically defined population in Tayside, Scotland.

PARTICIPANTS

2378 people prescribed and dispensed liquid methadone between January 1993 and February 2004.

MAIN OUTCOME MEASURES

All cause mortality (primary outcome) and drug dependent cause specific mortality (secondary outcome) by means of Cox proportional hazards models during 12 years of follow-up.

RESULTS

Overall, 181 (8%) people died. Overuse of methadone (adjusted hazard ratio 1.67, 95% confidence interval 1.05 to 2.67), history of psychiatric admission (2.47, 1.67 to 3.66), and increasing comorbidity measured as Charlson index >or=3 (1.20, 1.15 to 1.26) were all associated with an increase in all cause mortality. Longer duration of use (adjusted hazard ratio 0.95, 0.94 to 0.96), history of having urine tested (0.33, 0.22 to 0.49), and increasing time since last filled prescription were protective in relation to all cause mortality. Drug dependence was identified as the principal cause of death in 60 (33%) people. History of psychiatric admission was significantly associated with drug dependent death (adjusted hazard ratio 2.41, 1.25 to 4.64), as was history of prescription of benzodiazepines (4.35, 1.32 to 14.30).

CONCLUSIONS

Important elements of care in provision of methadone maintenance treatment are likely to influence, or be a marker for, a person's risk of death.

Hospitalizations for opioid poisoning: a nation-wide population-based study in Denmark, 1998-2004

AIMS

To assess hospitalization rates (HR) for poisoning with heroin, methadone or strong analgesics and relate them to quantities of prescribed methadone and strong analgesics in Denmark between 1998 and 2004.

DESIGN

Population-based ecological study.

SETTINGS

We extracted data on all emergency department visits and hospital admissions registered in the Danish National Patient Registry with a diagnosis of poisoning with heroin (n = 1688), methadone (n = 173) or strong analgesics (n = 384). To ascertain sale of prescribed medications we used data from the Danish Medicines Agency.

MEASUREMENTS

Age- and gender-standardized HR and defined daily doses (DDD) per 1000 people per day.

FINDINGS

HR for heroin poisoning was 4.4 [95% confidence interval (CI): 3.8-4.9] per 100,000 person-years (p-y) in 1998 and 4.6 (CI: 4.0-5.2) per 100,000 p-y in 2004. HR for methadone poisoning increased from 0.1 (CI: 0.0-0.2) per 100,000 p-y in 1998 to 1.1 (CI: 0.8-1.4) per 100,000 p-y in 2004. HR for poisoning with strong analgesics increased from 0.6 (CI: 0.4-0.9) per 100,000 p-y in 1998 to 2.1 (CI: 1.8-2.6) per 100,000 p-y in 2004. The sale of prescribed strong analgesics (5.0 DDD per 1000 people per day in 1998 to 5.9 DDD in 2004) and methadone (3.0 DDD per 1000 people per day in 1998 to 3.4 DDD in 2004) increased slightly between 1998 and 2004.

CONCLUSION

Increasing sale of prescribed methadone and strong analgesics coincided with increasing HRs of poisoning with these drugs, whereas HR of heroin poisoning varied. Further longitudinal studies are important for the guidance of future policy making.

Overdose training and take-home naloxone for opiate users: prospective cohort study of impact on knowledge and attitudes and subsequent management of overdoses

AIM

To examine the impact of training in overdose management and naloxone provision on the knowledge and confidence of current opiate users; and to record subsequent management of overdoses that occur during a 3-month follow-up period.

DESIGN

Repeated-measures design to examine changes in knowledge and confidence immediately after overdose management training; retention of knowledge and confidence at 3 months; and prospective cohort study design to document actual interventions applied at post-training overdose situations.

METHOD

A total of 239 opiate users in treatment completed a pre-training questionnaire on overdose management and naloxone administration and were re-assessed immediately post-training, at which point they were provided with the take-home emergency supply of naloxone. Three months later they were re-interviewed.

RESULTS

Significant improvements were seen in knowledge of risks of overdose, characteristics of overdose and appropriate actions to be taken; and in confidence in the administration of naloxone. A 78% follow-up rate was achieved (186 of 239) among whom knowledge of both the risks and physical/behavioural characteristics of overdose and also of recommended management actions was well retained. Eighteen overdoses (either experienced or witnessed) had occurred during the 3 months between the training and the follow-up. Naloxone was used on 12 occasions (a trained client's own supply on 10 occasions). One death occurred in one of the six overdoses where naloxone was not used. Where naloxone was used, all 12 resulted in successful reversal.

CONCLUSIONS

With overdose management training, opiate users can be trained to execute appropriate actions to assist the successful reversal of potentially fatal overdose. Wider provision may reduce drug-related deaths further. Future studies should examine whether public policy of wider overdose management training and naloxone provision could reduce the extent of opiate overdose fatalities, particularly at times of recognized increased risk.

Awareness of the need for safe storage of methadone at home is not improved by the use of protocols on recording information giving

BACKGROUND

Methadone is a synthetic, narcotic analgesic used in the treatment of drug misuse. Tragedies involving children being poisoned by the accidental ingestion of methadone are no longer a rare occurrence. Following an audit of the effectiveness of the provision and recall of information to patients attending an NHS Methadone Clinic a protocol was introduced to ensure that staff documented the provision of such information and patients gave a written confirmation that they had received the information.

METHODS

The study was undertaken in the setting of an NHS methadone clinic with the aim of re- auditing the storage of methadone at home following the introduction of the new protocols. 174 patients completed an anonymous questionnaire regarding where they store methadone at home and whether they recall being given advice about safe storage. Community pharmacists were contacted by telephone to assess the level of advice given to methadone patients regarding safety.

RESULTS

Only 49 (28.2%) patients recalled being given advice about safe storage, 24 (13.8%) recalled that information was provided by clinic staff. 170 (97.7%) patients regard methadone as being dangerous. (28.2%). Methadone is most commonly stored in a cupboard (37.9%). All methadone is dispensed in a bottle with a child resistant cap on it. All patients reported they stored their methadone in the original bottle provided by the pharmacist.

CONCLUSION

Recall of information on safety issues is very poor. Provision of written as well as verbal information is needed. The use of printed safety information cards which patients can take away for future reference may be of use. It is the responsibility of health professionals to ensure they provide information and advice to methadone users on the safe storage of their methadone at home.

Endogenous opiates and behavior: 2006

This paper is the 29th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning 30 years of research. It summarizes papers published during 2006 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurological disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).

Community pharmacies and the provision of opioid substitution services for drug misusers: changes in activity and attitudes of community pharmacists across England 1995-2005

AIMS

In England, the role of community pharmacy in service provision to drug misusers was studied in 1995. Extensive involvement was identified, and considerable underused capacity was noted. This study explores these and potential new roles 10 years on.

DESIGN

Cross-sectional national study. Postal survey (three mailshots), plus a fourth telephone follow-up using a structured questionnaire based on the 1995 questionnaire.

SETTING

Community pharmacies in England.

MEASUREMENTS

Involvement in opioid substitution therapy services (e.g. methadone, buprenorphine) and related activities. Attitudes towards service provision and novel services.

FINDINGS

A 95% response rate was obtained. This was higher than in 1995, due largely to the use of a telephone follow-up. There had been an increase in the proportion providing substitution therapy dispensing services from 51% to 63% and in the average current case-load (from 5.9 to 9.2); and consequently a large increase in the numbers being treated (approximately x 1.9). Similarly, supervised consumption of methadone and buprenorphine was being provided more widely (increasing from 0 to 59% of all responding pharmacists). Attitudes towards existing roles were more positive than in 1995, and providers tended to be more positive than non-providers. For newer roles (e.g. supervise medications for comorbidity; provide hepatitis B vaccination), there was support from around one-quarter of respondents.

CONCLUSION

Community pharmacy continues to play an important role in delivering treatment, including prescribing services, to drug misusers. There still appears to be untapped capacity, and moderate support for newer roles.

Changes to the daily pattern of methadone-related deaths in England and Wales, 1993–2003

Previous studies suggest that fatal poisoning deaths involving methadone occur more frequently on the weekends. We assessed changes in the daily pattern of mortality because of methadone poisoning following a review of drug misuse services in 1996 and publication of revised clinical guidelines in 1999. We also compared this to the daily pattern of deaths involving heroin/morphine. The Office for National Statistics provided data on all deaths in England and Wales between 1993 and 2003 for which methadone and heroin/morphine were mentioned on the coroner's certificate of death registration after inquest, with or without alcohol or other drugs. There were 3098 deaths involving methadone. The death rate increased up to 1997 and then declined. Initially, there was a marked excess of deaths occurring on Saturdays. The rate of decline was greatest for deaths occurring on Saturdays. As a result, the Saturday peak disappeared (P = 0.006). There were 6328 deaths involving heroin/morphine. No change in the daily pattern of heroin/morphine deaths was observed during the study period. Although the marked change in the epidemiology of methadone deaths coincided with recommendations for service redevelopment and clinical management of methadone treatment, the contribution of improved prescribing practice or treatment services is unclear.