Mortality related to pharmacotherapies for opioid dependence: a comparative analysis of coronial records

Geographic variation in availability of opioid treatment programs across U.S. communities

Methadone for Opioid Use Disorder (OUD) treatment is only dispensed at Opioid Treatment Programs (OTPs). Little is known about the geographic variation in OTP availability and community characteristics associated with the availability across smaller geographic communities in the U.S. To (1) describe geographic distribution of OTPs and (2) examine OTP availability by community characteristics in the contiguous U.S. at Zip Code Area Tabulation (ZCTA) level. Logistic regression was used to examine community characteristics associated with OTP availability (N = 30,367). Chi-square and t-tests were conducted to examine statistically significant differences in OTP availability. Maps and descriptive statistics were used to examine geographic variation in OTP availability. Only 5% (1,417) of ZCTAs had at least one OTP for a total of 1,682 OTPs. Rural ZCTAs had 50% lower odds of having an OTP compared to urban ZCTAs [AOR 0.5; (95% CI: 0.41-0.60)]. ZCTAs in the lowest income quartile had higher odds of having an OTP compared to ZCTAs in the highest income quartile [AOR 3.4; (95% CI: 2.71-4.18)]. Further, ZCTAs with OTPs had a higher proportion of minority residents [Black: 17.5% vs. 7.2%; Hispanic: 19.2% vs. 9%] and a lower proportion of White residents [55.1% vs. 78.2%]. Nationally, OTPs are extremely scarce with notable regional and urban-rural disparities. Potential solutions to address these disparities are discussed.

Concomitant drugs with buprenorphine user deaths

BACKGROUND

Buprenorphine is abused in several countries notwithstanding its benefits as an analgesic and as an opioid agonist treatment medication. Benzodiazepines and alcohol have previously been associated with buprenorphine toxicity. This study elucidates the role of emerging concomitant drugs in different groups of buprenorphine user deaths.

METHODS

All cases in the Finnish national post-mortem toxicology database from 2016-2019 in which buprenorphine or norbuprenorphine was a laboratory finding in any post-mortem specimen and age at death of 15-64 years were investigated for cause and manner of death, concurrent drug and alcohol findings, age, and gender.

RESULTS

There were 792 deaths with a buprenorphine finding, of which buprenorphine was implicated in poisoning without other opioids in 271 cases (34 %). In this group of buprenorphine poisoning deaths, concomitant benzodiazepines were found in 94 % (clonazepam 53 %), illicit drugs in 63 %, gabapentinoids in 50 % (pregabalin 41 %), alcohol in 41 %, antidepressants in 32 %, and antipsychotics in 28 % of cases; only three deaths showed no benzodiazepines, alcohol, or gabapentinoids. Polydrug use was common regardless of the cause of death. In the age group 15 to 24 years, concomitant use of benzodiazepines and illicit drugs, and buprenorphine poisoning were more prevalent than in the age group 25-64 years.

CONCLUSIONS

The unprecedentedly high concomitant use of benzodiazepines in buprenorphine user deaths obscures other possible pharmacological risk factors for buprenorphine poisoning that could be relevant for prevention. Higher mortality in the younger age group suggests particularly unsafe drug use patterns that should be addressed.

Emerging Viral and Bacterial Infections: Within an Era of Opioid Epidemic

The opioid epidemic is a public health crisis that continues to impact healthcare in the United States of America (USA). While changes in opioid prescribing have curbed the medical use of opioids, the increase in nonmedical use, largely driven by injection drug use (IDU), has contributed to the escalating incidence of opioid use disorder (OUD). Furthermore, IDU is associated with high-risk injection practices that can increase the risk of acquiring viral and bacterial infections. Here in this comprehensive review, we aimed to summarize the epidemiology and management of OUD, along with the screening and antimicrobial treatment of associated infections, specifically focused on human immunodeficiency virus, hepatitis C virus, skin and soft tissue infections, endocarditis, and osteomyelitis. Medication-assisted therapy (MAT) and infection guidelines from the USA will be presented.

Optimizing the impact of medications for opioid use disorder at release from prison and jail settings: A microsimulation modeling study

BACKGROUND

We examined the impact of expanded access to medications for opioid use disorder (MOUD) in a unified prison and jail system on post-release, opioid-related overdose mortality.

METHODS

We developed a microsimulation model to simulate a population of 55,000 persons at risk of opioid-related overdose mortality in Rhode Island. The effect of an extended-release (XR) naltrexone only intervention and the effect of providing access to all three MOUD (i.e., methadone, buprenorphine, and XR-naltrexone) at release from incarceration on cumulative overdose death over eight years (2017-2024) were compared to the standard of care (i.e., limited access to MOUD).

RESULTS

In the standard of care scenario, the model predicted 2385 opioid-related overdose deaths between 2017 and 2024. An XR-naltrexone intervention averted 103 deaths (4.3% reduction), and access to all three MOUD averted 139 deaths (5.8% reduction). Among those with prior year incarceration, an XR-naltrexone only intervention and access to all three MOUD reduced overdose deaths by 22.8% and 31.6%, respectively.

CONCLUSIONS

Expanded access to MOUD in prison and jail settings can reduce overdose mortality in a general, at-risk population. However, the real-world impact of this approach will vary by levels of incarceration, treatment enrollment, and post-release retention.

Interventions for female drug-using offenders

BACKGROUND

This review represents one in a family of three reviews focusing on the effectiveness of interventions in reducing drug use and criminal activity for offenders.

OBJECTIVES

To assess the effectiveness of interventions for female drug-using offenders in reducing criminal activity, or drug use, or both.

SEARCH METHODS

We searched 12 electronic bibliographic databases up to February 2019.

SELECTION CRITERIA

We included randomised controlled trials (RCTs).

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 13 trials with 2560 participants. Interventions were delivered in prison (7/13 studies, 53%) and community (6/13 studies, 47%) settings. The rating of bias was affected by the lack of clear reporting by authors, and we rated many items as 'unclear'. In two studies (190 participants) collaborative case management in comparison to treatment as usual did not reduce drug use (risk ratio (RR) 0.65, 95% confidence interval (CI) 0.20 to 2.12; 1 study, 77 participants; low-certainty evidence), reincarceration at nine months (RR 0.71, 95% CI 0.32 to 1.57; 1 study, 77 participants; low-certainty evidence), and number of subsequent arrests at 12 months (RR 1.11, 95% CI 0.83 to 1.49; 1 study, 113 participants; low-certainty evidence). One study (36 participants) comparing buprenorphine to placebo showed no significant reduction in self-reported drug use at end of treatment (RR 0.57, 95% CI 0.27 to 1.20) and three months (RR 0.58, 95% CI 0.25 to 1.35); very low-certainty evidence. No adverse events were reported. One study (38 participants) comparing interpersonal psychotherapy to a psychoeducational intervention did not find reduction in drug use at three months (RR 0.67, 95% CI 0.30 to 1.50; low-certainty evidence). One study (31 participants) comparing acceptance and commitment therapy (ACT) to a waiting list showed no significant reduction in self-reported drug use using the Addiction Severity Index (mean difference (MD) -0.04, 95% CI -0.37 to 0.29) and abstinence from drug use at six months (RR 2.89, 95% CI 0.73 to 11.43); low-certainty evidence. One study (314 participants) comparing cognitive behavioural skills to a therapeutic community programme and aftercare showed no significant reduction in self-reported drug use (RR 0.86, 95% CI 0.58 to 1.27), re-arrest for any type of crime (RR 0.73, 95% CI 0.52 to 1.03); criminal activity (RR 0.80, 95% CI 0.63 to 1.03), or drug-related crime (RR 0.95, 95% CI 0.68 to 1.32). A significant reduction for arrested (not for parole) violations at six months follow-up was significantly in favour of cognitive behavioural skills (RR 0.43, 95% CI 0.25 to 0.77; very low-certainty evidence). A second study with 115 participants comparing cognitive behavioural skills to an alternative substance abuse treatment showed no significant reduction in reincarceration at 12 months (RR 0.70, 95% CI 0.43 to 1.12; low certainty-evidence. One study (44 participants) comparing cognitive behavioural skills and standard therapy versus treatment as usual showed no significant reduction in Addiction Severity Index (ASI) drug score at three months (MD 0.02, 95% CI -0.05 to 0.09) and six months (MD -0.02, 95% CI -0.09 to 0.05), and incarceration at three months (RR 0.46, 95% CI 0.04 to 4.68) and six months (RR 0.51, 95% CI 0.20 to 1.27); very low-certainty evidence. One study (171 participants) comparing a single computerised intervention versus case management showed no significant reduction in the number of days not using drugs at three months (MD -0.89, 95% CI -4.83 to 3.05; low certainty-evidence). One study (116 participants) comparing dialectic behavioural therapy and case management (DBT-CM) versus a health promotion intervention showed no significant reduction at six months follow-up in positive drug testing (RR 0.67, 95% CI 0.43 to 1.03), number of people not using marijuana (RR 1.23, 95% CI 0.95 to 1.59), crack (RR 1.00, 95% CI 0.87 to 1.14), cocaine (RR 1.02, 95% CI 0.93 to 1.12), heroin (RR 1.05, 95% CI 0.98 to 1.13), methamphetamine (RR 1.02, 95% CI 0.87 to 1.20), and self-reported drug use for any drug (RR 1.20, 95% CI 0.92 to 1.56); very low-certainty evidence. One study (211 participants) comparing a therapeutic community programme versus work release showed no significant reduction in marijuana use at six months (RR 1.03, 95% CI 0.19 to 5.65), nor 18 months (RR 1.00, 95% CI 0.07 to 14.45), heroin use at six months (RR 1.59, 95% CI 0.49 to 5.14), nor 18 months (RR 1.92, 95% CI 0.24 to 15.37), crack use at six months (RR 2.07, 95% CI 0.41 to 10.41), nor 18 months (RR 1.64, 95% CI 0.19 to 14.06), cocaine use at six months (RR 1.09, 95% CI 0.79 to 1.50), nor 18 months (RR 0.93, 95% CI 0.64 to 1.35). It also showed no significant reduction in incarceration for drug offences at 18 months (RR 1.45, 95% CI 0.87 to 2.42); with overall very low- to low-certainty evidence. One study (511 participants) comparing intensive discharge planning and case management versus prison only showed no significant reduction in use of marijuana (RR 0.79, 95% CI 0.53 to 1.16), hard drugs (RR 1.12, 95% CI 0.88 to 1.43), crack cocaine (RR 1.08, 95% CI 0.75 to 1.54), nor positive hair testing for marijuana (RR 0.75, 95% CI 0.55 to 1.03); it found a significant reduction in arrests (RR 0.19, 95% CI 0.04 to 0.87), but no significant reduction in drug charges (RR 1.07, 95% CI 0.75 to 1.53) nor incarceration (RR 1.09, 95% CI 0.86 to 1.39); moderate-certainty evidence. One narrative study summary (211 participants) comparing buprenorphine pre- and post-release from prison showed no significant reduction in drug use at 12 months post-release; low certainty-evidence. No adverse effects were reported.

AUTHORS' CONCLUSIONS

The studies showed a high degree of heterogeneity for types of comparisons, outcome measures and small samples. Descriptions of treatment modalities are required. On one outcome of arrest (no parole violations), we identified a significant reduction when cognitive behavioural therapy (CBT) was compared to a therapeutic community programme. But for all other outcomes, none of the interventions were effective. Larger trials are required to increase the precision of confidence about the certainty of evidence.

Circumstances of death of opioid users being treated with naltrexone

BACKGROUND AND AIMS

Naltrexone is an opioid antagonist used as a maintenance drug for the treatment of opioid dependence and in opioid withdrawal regimens. The current study aimed to: (1) determine the clinical characteristics and circumstances of death of people undergoing naltrexone treatment for opioid dependence; and (2) determine the blood toxicology of cases including naltrexone concentrations, the presence of other drugs and a comparison of morphine concentrations in the presence and absence of naltrexone.

DESIGN

Retrospective study of all deaths among people undergoing naltrexone treatment for opioid dependence retrieved from the National Coronial Information System, 2000-17.

SETTING

Australia-wide.

CASES

Seventy-four cases, with a mean age of 32.5 years; 81.1% male.

MEASUREMENTS

Information was collected on demographics, manner of death, naltrexone treatment history, toxicology and major organ pathology.

FINDINGS

Death was attributed to opioid toxicity in 86.5% of cases: accidental (79.7%), deliberate (6.8%). In 55.4% of all cases the decedent was maintained on oral naltrexone and 32.4% had a recent naltrexone implant. In five cases the decedent was undergoing opioid detoxification. Among those screened for naltrexone, naltrexone was present in the blood or urine of 52.5% (15.8% of oral maintenance cases, 85.7% of implant cases). Fourteen cases were known to have died from opioid toxicity with naltrexone present in their blood or urine. The median blood naltrexone concentrations were within the reported therapeutic range.

CONCLUSIONS

The primary cause of death among people undergoing naltrexone treatment for opioid dependence in Australia from 2000 to 2017 was opioid toxicity, the majority of cases having been maintained on oral naltrexone. Cases in which naltrexone was not detected indicate the importance of treatment compliance. Deaths due to opioid toxicity where naltrexone was present indicates the possibility of overdose while naltrexone medication is maintained.

Potential uses of naltrexone in emergency department patients with opioid use disorder

Introduction: Despite widespread recognition of the opioid crisis, opioid overdose remains a common reason for Emergency Department (ED) utilization. Treatment for these patients after stabilization often involves the provision of information for outpatient treatment options. Ideally, an ED visit for overdose would present an opportunity to start treatment for opioid use disorder (OUD) immediately. Although widely recognized as effective, opioid agonist therapy with methadone and buprenorphine commonly referred to as "medication-assisted therapy" but more correctly as "medication for addiction treatment" (MAT), can be difficult to access even for motivated individuals due to shortages of prescribers and treatment programs. Moreover, opioid agonist therapy may not be appropriate for all patients, as many patients who present after overdose are not opioid dependent. More treatment options are required to successfully match patients with diverse needs to an optimal treatment plan in order to avoid relapse. Naltrexone, a long-acting opioid antagonist, available orally and as a monthly extended-release intramuscular injection, may represent another treatment option. Methods: We conducted a literature search of MEDLINE and PubMed. We aimed to capture references related to naltrexone and is use as MAT for OUD, as well as manuscripts that discussed naltrexone in comparison toother agents used for MAT, opioid detoxification, and naltrexone metabolism. Our initial search logic returned a total of 618 articles. Following individual evaluation for relevance, we selected 65 for in-depthreview. Manuscripts meeting criteria were examined for citations meriting further review, leading to the addition of 30 manuscripts Conclusions: Here, we review the pharmacology of naltrexone as it relates to OUD, its history of use, and highlight recent studies and new approaches for use of the drug as MAT including its potential initiation after ED visit for opioid overdose.

The neurobiology of addiction

Substance and alcohol use disorders impose large health and economic burdens on individuals, families, communities, and society. Neither prevention nor treatment efforts are effective in all individuals. Results are often modest. Advances in neuroscience and addiction research have helped to describe the neurobiological changes that occur when a person transitions from recreational substance use to a substance use disorder or addiction. Understanding both the drivers and consequences of substance use in vulnerable populations, including those whose brains are still maturing, has revealed behavioral and biological characteristics that can increase risks of addiction. These findings are particularly timely, as law- and policymakers are tasked to reverse the ongoing opioid epidemic, as more states legalize marijuana, as new products including electronic cigarettes and newly designed abused substances enter the legal and illegal markets, and as "deaths of despair" from alcohol and drug misuse continue.

Accounting for the uncounted: Physical and affective distress in individuals dropping out of oral naltrexone treatment for opioid use disorder

BACKGROUND

The theoretical benefits of naltrexone as a treatment for opioid use disorder (e.g., safety, non-addictive, low risk of diversion) stand in sharp contrast to its disappointing record on retention in most samples. The relationship of uncomfortable physical and dysphoric symptoms to retention on naltrexone is a controversial and under-studied issue.

METHODS

Using data from a randomized controlled trial of voucher-based contingency management and support from a significant other to enhance retention on oral naltrexone, we compared self-reported somatic and dysphoric symptoms, measured weekly, for individuals who were retained on naltrexone through the 12-week trial (n = 50) versus those who dropped out (n = 70).

RESULTS

There were no differences between participants who completed treatment and those who dropped out on multiple baseline characteristics, including somatic or affective symptoms prior to treatment. However, whether analyzed cross-sectionally or over time, participants who dropped out consistently reported higher rates of somatic symptoms, particularly difficulty sleeping, as well as affective symptoms, including multiple indicators of depression, anxiety, and anhedonia.

CONCLUSIONS

Although the smaller group of participants who were retained on oral naltrexone for 12 weeks reported decreasing physical and affective discomfort over time, there was substantial evidence that those who dropped out experienced continued and significant levels of distress. Individuals who report physical or affective distress while taking naltrexone may be at higher risk of dropout.

Medication for Opioid Use Disorder After Nonfatal Opioid Overdose and Association With Mortality: A Cohort Study

Background

Opioid overdose survivors have an increased risk for death. Whether use of medications for opioid use disorder (MOUD) after overdose is associated with mortality is not known.

Objective

To identify MOUD use after opioid overdose and its association with all-cause and opioid-related mortality.

Design

Retrospective cohort study.

Setting

7 individually linked data sets from Massachusetts government agencies.

Participants

17 568 Massachusetts adults without cancer who survived an opioid overdose between 2012 and 2014.

Measurements

Three types of MOUD were examined: methadone maintenance treatment (MMT), buprenorphine, and naltrexone. Exposure to MOUD was identified at monthly intervals, and persons were considered exposed through the month after last receipt. A multivariable Cox proportional hazards model was used to examine MOUD as a monthly time-varying exposure variable to predict time to all-cause and opioid-related mortality.

Results

In the 12 months after a nonfatal overdose, 2040 persons (11%) enrolled in MMT for a median of 5 months (interquartile range, 2 to 9 months), 3022 persons (17%) received buprenorphine for a median of 4 months (interquartile range, 2 to 8 months), and 1099 persons (6%) received naltrexone for a median of 1 month (interquartile range, 1 to 2 months). Among the entire cohort, all-cause mortality was 4.7 deaths (95% CI, 4.4 to 5.0 deaths) per 100 person-years and opioid-related mortality was 2.1 deaths (CI, 1.9 to 2.4 deaths) per 100 person-years. Compared with no MOUD, MMT was associated with decreased all-cause mortality (adjusted hazard ratio [AHR], 0.47 [CI, 0.32 to 0.71]) and opioid-related mortality (AHR, 0.41 [CI, 0.24 to 0.70]). Buprenorphine was associated with decreased all-cause mortality (AHR, 0.63 [CI, 0.46 to 0.87]) and opioid-related mortality (AHR, 0.62 [CI, 0.41 to 0.92]). No associations between naltrexone and all-cause mortality (AHR, 1.44 [CI, 0.84 to 2.46]) or opioid-related mortality (AHR, 1.42 [CI, 0.73 to 2.79]) were identified.

Limitation

Few events among naltrexone recipients preclude confident conclusions.

Conclusion

A minority of opioid overdose survivors received MOUD. Buprenorphine and MMT were associated with reduced all-cause and opioid-related mortality.

Primary Funding Source

National Center for Advancing Translational Sciences of the National Institutes of Health.

Current Concepts in Methadone Metabolism and Transport

Methadone is a cornerstone therapy for opioid addiction and a public health strategy for HIV/AIDS and hepatitis C reduction. Methadone is also used for acute and chronic pain. As use for chronic pain has grown, so too have adverse events. Constitutive and acquired (drug interactions) inter- and intraindividual variability in methadone pharmacokinetics and pharmacodynamics confounds reliable clinical use. Identification of enzymes and transporters responsible for methadone disposition has been a long-sought ideal. Initial in vitro studies identified CYP3A4 as metabolizing methadone. Subsequently, by extrapolation, CYP3A4 was long assumed to be responsible for clinical methadone disposition. However, CYP2B6 is also a major catalyst of methadone metabolism in vitro. It has now been unequivocally established that CYP2B6, not CYP3A4, is the principal determinant of methadone metabolism, clearance, elimination, and plasma concentrations in humans. Methadone disposition is susceptible to inductive and inhibitory drug interactions. CYP2B6 genetics also influences methadone metabolism and clearance, which were diminished in CYP2B6*6 carriers and increased in CYP2B6*4 carriers. CYP2B6 genetics can explain, in part, interindividual variability in methadone metabolism and clearance. Thus, both constitutive variability due to CYP2B6 genetics, and CYP2B6-mediated drug interactions, can alter methadone disposition, clinical effect, and drug safety. Methadone is not a substrate for major influx or efflux transporters.

Antagonists in the medical management of opioid use disorders: Historical and existing treatment strategies

BACKGROUND AND OBJECTIVES

Opioid use disorder (OUD) is a chronic condition with potentially severe health and social consequences. Many who develop moderate to severe OUD will repeatedly seek treatment or interact with medical care via emergency department visits or hospitalizations. Thus, there is an urgent need to develop feasible and effective approaches to help persons with OUD achieve and maintain abstinence from opioids. Treatment that includes one of the three FDA-approved medications is an evidence-based strategy to manage OUD. The purpose of this review is to address practices for managing persons with moderate to severe OUD with a focus on opioid withdrawal and naltrexone-based relapse-prevention treatment.

METHODS

Literature available on PubMed was used to review the evolution of treatment strategies from the 1960s onward to manage opioid withdrawal and initiate treatment with naltrexone.

RESULTS

Emerging practices for extended-release naltrexone induction include the use of agonist tapers and adjuvant medications. Clinical challenges frequently encountered when initiating this therapy include managing withdrawal and ongoing opioid use during treatment. Clinical factors may inform decisions regarding patient selection and length of naltrexone treatment, such as recent opioid use and patient preferences.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

Treatment strategies to manage opioid withdrawal have evolved, but many patients with OUD do not receive medication for the prevention of relapse. Clinical strategies for induction onto extended-release naltrexone are now available and can be safely and effectively implemented in specialty and select primary care settings. (© 2018 The Authors. The American Journal on Addictions Published by Wiley Periodicals, Inc. on behalf of The American Academy of Addiction Psychiatry (AAAP);27:177-187).

Comparative effectiveness of extended-release naltrexone versus buprenorphine-naloxone for opioid relapse prevention (X:BOT): a multicentre, open-label, randomised controlled trial

BACKGROUND

Extended-release naltrexone (XR-NTX), an opioid antagonist, and sublingual buprenorphine-naloxone (BUP-NX), a partial opioid agonist, are pharmacologically and conceptually distinct interventions to prevent opioid relapse. We aimed to estimate the difference in opioid relapse-free survival between XR-NTX and BUP-NX.

METHODS

We initiated this 24 week, open-label, randomised controlled, comparative effectiveness trial at eight US community-based inpatient services and followed up participants as outpatients. Participants were 18 years or older, had Diagnostic and Statistical Manual of Mental Disorders-5 opioid use disorder, and had used non-prescribed opioids in the past 30 days. We stratified participants by treatment site and opioid use severity and used a web-based permuted block design with random equally weighted block sizes of four and six for randomisation (1:1) to receive XR-NTX or BUP-NX. XR-NTX was monthly intramuscular injections (Vivitrol; Alkermes) and BUP-NX was daily self-administered buprenorphine-naloxone sublingual film (Suboxone; Indivior). The primary outcome was opioid relapse-free survival during 24 weeks of outpatient treatment. Relapse was 4 consecutive weeks of any non-study opioid use by urine toxicology or self-report, or 7 consecutive days of self-reported use. This trial is registered with ClinicalTrials.gov, NCT02032433.

FINDINGS

Between Jan 30, 2014, and May 25, 2016, we randomly assigned 570 participants to receive XR-NTX (n=283) or BUP-NX (n=287). The last follow-up visit was Jan 31, 2017. As expected, XR-NTX had a substantial induction hurdle: fewer participants successfully initiated XR-NTX (204 [72%] of 283) than BUP-NX (270 [94%] of 287; p<0·0001). Among all participants who were randomly assigned (intention-to-treat population, n=570) 24 week relapse events were greater for XR-NTX (185 [65%] of 283) than for BUP-NX (163 [57%] of 287; hazard ratio [HR] 1·36, 95% CI 1·10-1·68), most or all of this difference accounted for by early relapse in nearly all (70 [89%] of 79) XR-NTX induction failures. Among participants successfully inducted (per-protocol population, n=474), 24 week relapse events were similar across study groups (p=0·44). Opioid-negative urine samples (p<0·0001) and opioid-abstinent days (p<0·0001) favoured BUP-NX compared with XR-NTX among the intention-to-treat population, but were similar across study groups among the per-protocol population. Self-reported opioid craving was initially less with XR-NTX than with BUP-NX (p=0·0012), then converged by week 24 (p=0·20). With the exception of mild-to-moderate XR-NTX injection site reactions, treatment-emergent adverse events including overdose did not differ between treatment groups. Five fatal overdoses occurred (two in the XR-NTX group and three in the BUP-NX group).

INTERPRETATION

In this population it is more difficult to initiate patients to XR-NTX than BUP-NX, and this negatively affected overall relapse. However, once initiated, both medications were equally safe and effective. Future work should focus on facilitating induction to XR-NTX and on improving treatment retention for both medications.

FUNDING

NIDA Clinical Trials Network.

Which medications are suitable for agonist drug maintenance?

BACKGROUND AND AIMS

We examine the feasibility of agonist maintenance treatment for the major psychoactive drug classes: opioids, nicotine, benzodiazepines, cannabis, psychostimulants and alcohol.

METHODS

Eight clinical criteria for an agonist maintenance drug were assessed for each major drug class. These related to pharmacological aspects of the drug (agonist, pharmacological stability, dose-response, non-toxic) and neurocognitive sequelae (psychiatric, cognitive, craving, salience).

RESULTS

Opioids and nicotine met all eight criteria for a maintenance drug. While nicotine has not been promoted widely or used for maintenance, it has the potential to fulfil that role. Cannabis met five criteria and has potential, but long-term data on cognitive impairment are required. Benzodiazepine maintenance would appear an option for the high-dose chaotic abuser, also meeting five criteria, although clinic dosing appears the safest option. Psychostimulants (three of eight criteria) and alcohol (one of eight) appear poor propositions for maintenance, in terms of both their pharmacological and their neurocognitive characteristics.

CONCLUSIONS

Drug classes have properties that distinguish them in their suitability for maintenance treatment. Some classes not yet used for maintenance (notably nicotine and cannabis) have potential to fulfil such a role. Others, however, by their inherent nature, appear unsuitable for such a treatment regimen.

Prescription Opioid Misuse, Abuse, and Treatment in the United States: An Update

OBJECTIVE

Prescription opioid abuse and dependence have escalated rapidly in the United States over the past 20 years, leading to high rates of overdose deaths and a dramatic increase in the number of people seeking treatment for opioid dependence. The authors review the scope of the abuse and overdose epidemic, prescription practices, and the assessment, treatment, and prevention of prescription opioid misuse and dependence.

METHOD

The authors provide an overview of the literature from 2006 to the present, with the twin goals of highlighting advances in prevention and treatment and identifying remaining gaps in the science.

RESULTS

A number of policy and educational initiatives at the state and federal government level have been undertaken in the past 5 years to help providers and consumers, respectively, prescribe and use opioids more responsibly. Initial reports suggest that diversion and abuse levels have begun to plateau, likely as a result of these initiatives. While there is a large body of research suggesting that opioid substitution coupled with psychosocial interventions is the best treatment option for heroin dependence, there is limited research focusing specifically on the treatment of prescription opioid dependence. In particular, the treatment of chronic pain in individuals with prescription opioid use disorders is underexplored.

CONCLUSIONS

While policy and educational initiatives appear to be effective in decreasing prescription opioid abuse and misuse, research focusing on the development and evaluation of treatments specific to prescription opioid dependence and its common comorbidities (e.g., chronic pain, depression) is critically needed.

Pharmacological interventions for drug-using offenders

BACKGROUND

The review represents one in a family of four reviews focusing on a range of different interventions for drug-using offenders. This specific review considers pharmacological interventions aimed at reducing drug use or criminal activity, or both, for illicit drug-using offenders.

OBJECTIVES

To assess the effectiveness of pharmacological interventions for drug-using offenders in reducing criminal activity or drug use, or both.

SEARCH METHODS

We searched Fourteen electronic bibliographic databases up to May 2014 and five additional Web resources (between 2004 and November 2011). We contacted experts in the field for further information.

SELECTION CRITERIA

We included randomised controlled trials assessing the efficacy of any pharmacological intervention a component of which is designed to reduce, eliminate or prevent relapse of drug use or criminal activity, or both, in drug-using offenders. We also report data on the cost and cost-effectiveness of interventions.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by Cochrane.

MAIN RESULTS

Fourteen trials with 2647 participants met the inclusion criteria. The interventions included in this review report on agonistic pharmacological interventions (buprenorphine, methadone and naltrexone) compared to no intervention, other non-pharmacological treatments (e.g. counselling) and other pharmacological drugs. The methodological trial quality was poorly described, and most studies were rated as 'unclear' by the reviewers. The biggest threats to risk of bias were generated through blinding (performance and detection bias) and incomplete outcome data (attrition bias). Studies could not be combined all together because the comparisons were too different. Only subgroup analysis for type of pharmacological treatment were done. When compared to non-pharmacological, we found low quality evidence that agonist treatments are not effective in reducing drug use or criminal activity, objective results (biological) (two studies, 237 participants (RR 0.72 (95% CI 0.51 to 1.00); subjective (self-report), (three studies, 317 participants (RR 0.61 95% CI 0.31 to 1.18); self-report drug use (three studies, 510 participants (SMD: -0.62 (95% CI -0.85 to -0.39). We found low quality of evidence that antagonist treatment was not effective in reducing drug use (one study, 63 participants (RR 0.69, 95% CI 0.28 to 1.70) but we found moderate quality of evidence that they significantly reduced criminal activity (two studies, 114 participants, (RR 0.40, 95% CI 0.21 to 0.74).Findings on the effects of individual pharmacological interventions on drug use and criminal activity showed mixed results. In the comparison of methadone to buprenorphine, diamorphine and naltrexone, no significant differences were displayed for either treatment for self report dichotomous drug use (two studies, 370 participants (RR 1.04, 95% CI 0.69 to 1.55), continuous measures of drug use (one study, 81 participants, (mean difference (MD) 0.70, 95% CI -5.33 to 6.73); or criminal activity (one study, 116 participants, (RR 1.25, 95% CI 0.83 to 1.88) between methadone and buprenorphine. Similar results were found for comparisons with diamorphine with no significant differences between the drugs for self report dichotomous drug use for arrest (one study, 825 participants, (RR 1.25, 95% CI 1.03 to 1.51) or naltrexone for dichotomous measures of reincarceration (one study, 44 participants, (RR 1.10, 95% CI 0.37 to 3.26), and continuous outcome measure of crime, (MD -0.50, 95% CI -8.04 to 7.04) or self report drug use (MD 4.60, 95% CI -3.54 to 12.74).

AUTHORS' CONCLUSIONS

When compared to non-pharmacological treatment, agonist treatments did not seem effective in reducing drug use or criminal activity. Antagonist treatments were not effective in reducing drug use but significantly reduced criminal activity. When comparing the drugs to one another we found no significant differences between the drug comparisons (methadone versus buprenorphine, diamorphine and naltrexone) on any of the outcome measures. Caution should be taken when interpreting these findings, as the conclusions are based on a small number of trials, and generalisation of these study findings should be limited mainly to male adult offenders. Additionally, many studies were rated at high risk of bias.

Interventions for female drug-using offenders

BACKGROUND

This is an updated version of a Cochrane review first published in Issue 3, 2006 (Perry 2006). The review represents one in a family of four reviews focusing on the effectiveness of interventions in reducing drug use and criminal activity for offenders. This specific review considers interventions for female drug-using offenders.

OBJECTIVES

To assess the effectiveness of interventions for female drug-using offenders in reducing criminal activity, or drug use, or both.

SEARCH METHODS

We searched 14 electronic bibliographic databases up to May 2014 and five additional Website resources (between 2004 and November 2011). We contacted experts in the field for further information.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) designed to reduce, eliminate or prevent relapse of drug use or criminal activity in female drug-using offenders. We also reported data on the cost and cost-effectiveness of interventions.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

Nine trials with 1792 participants met the inclusion criteria. Trial quality and risks of bias varied across each study. We rated the majority of studies as being at 'unclear' risk of bias due to a lack of descriptive information. We divided the studies into different categories for the purpose of meta-analyses: for any psychosocial treatments in comparison to treatment as usual we found low quality evidence that there were no significant differences in arrest rates, (two studies; 489 participants; risk ratio (RR) 0.82, 95% confidence interval (CI) 0.45 to 1.52) or drug use (one study; 77 participants; RR 0.65, 95% CI 0.20 to 2.12), but we found moderate quality evidence that there was a significant reduction in reincarceration, (three studies; 630 participants; RR 0.46, 95% CI 0.34 to 0.64). Pharmacological intervention using buprenorphine in comparison to a placebo did not significantly reduce self reported drug use (one study; 36 participants; RR 0.58, 95% CI 0.25 to 1.35). No cost or cost-effectiveness evidence was reported in the studies.

AUTHORS' CONCLUSIONS

Three of the nine trials show a positive trend towards the use of any psychosocial treatment in comparison to treatment as usual showing an overall significant reduction in subsequent reincarceration, but not arrest rates or drug use. Pharmacological interventions in comparison to a placebo did not significantly reduce drug use and did not measure criminal activity. Four different treatment comparisons showed varying results and were not combined due to differences in the intervention and comparison groups. The studies overall showed a high degree of heterogeneity for types of comparisons and outcome measures assessed, which limited the possibility to pool the data. Descriptions of treatment modalities are required to identify the important elements for treatment success in drug-using female offenders. More trials are required to increase the precision of confidence with which we can draw conclusions about the effectiveness of treatments for female drug-using offenders.

Medication-assisted treatment of opioid use disorder: review of the evidence and future directions

Medication-assisted treatment of opioid use disorder with physiological dependence at least doubles rates of opioid-abstinence outcomes in randomized, controlled trials comparing psychosocial treatment of opioid use disorder with medication versus with placebo or no medication. This article reviews the current evidence for medication-assisted treatment of opioid use disorder and also presents clinical practice imperatives for preventing opioid overdose and the transmission of infectious disease. The evidence strongly supports the use of agonist therapies to reduce opioid use and to retain patients in treatment, with methadone maintenance remaining the gold standard of care. Combined buprenorphine/naloxone, however, also demonstrates significant efficacy and favorable safety and tolerability in multiple populations, including youth and prescription opioid-dependent individuals, as does buprenorphine monotherapy in pregnant women. The evidence for antagonist therapies is weak. Oral naltrexone demonstrates poor adherence and increased mortality rates, although the early evidence looks more favorable for extended-release naltrexone, which has the advantages that it is not subject to misuse or diversion and that it does not present a risk of overdose on its own. Two perspectives-individualized treatment and population management-are presented for selecting among the three available Food and Drug Administration-approved maintenance therapies for opioid use disorder. The currently unmet challenges in treating opioid use disorder are discussed, as are the directions for future research.

The effectiveness of opioid substitution treatments for patients with opioid dependence: a systematic review and multiple treatment comparison protocol

BACKGROUND

Opioids are psychoactive analgesic drugs prescribed for pain relief and palliative care. Due to their addictive potential, effort and vigilance in controlling prescriptions is needed to avoid misuse and dependence. Despite the effort, the prevalence of opioid use disorder continues to rise. Opioid substitution therapies are commonly used to treat opioid dependence; however, there is minimal consensus as to which therapy is most effective. Available treatments include methadone, heroin, buprenorphine, as well as naltrexone. This systematic review aims to assess and compare the effect of all available opioid substitution therapies on the treatment of opioid dependence.

METHODS/DESIGN

The authors will search Medline, EMBASE, PubMed, PsycINFO, Web of Science, Cochrane Library, Cochrane Clinical Trials Registry, World Health Organization International Clinical Trials Registry Platform Search Portal, and the National Institutes for Health Clinical Trials Registry. The title, abstract, and full-text screening will be completed in duplicate. When appropriate, multiple treatment comparison Bayesian meta-analytic methods will be performed to deduce summary statistics estimating the effectiveness of all opioid substitution therapies in terms of retention and response to treatment (as measured through continued opioid abuse).

DISCUSSION

Using evidence gained from this systematic review, we anticipate disseminating an objective review of the current available literature on the effectiveness of all opioid substitution therapies for the treatment of opioid use disorder. The results of this systematic review are imperative to the further enhancement of clinical practice in addiction medicine.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42013006507.

Psychological and physiological stress negatively impacts early engagement and retention of opioid-dependent individuals on methadone maintenance

The present study investigated whether psychological and/or physiological measures of stress would impede induction onto methadone maintenance and predict early (<6 months) discontinuation. Compared with controls, opioid-dependent subjects displayed increased distress on the perceived stress scale (PSS) and post-traumatic stress disorder checklist (PCLC); 60% exhibited abnormal cortisol. Addiction severity index (ASI), drug-use, and stress indices explained between 17 and 37% of the variance in engagement including attendance, opioid abstinence, and methadone stabilization. Participants who discontinued treatment displayed poor engagement, abnormal cortisol, elevated withdrawal symptoms, higher distress, and increased ongoing opioid use versus compliant individuals. Discontinuation was initially related to drug-use severity; however, by 6 months, retention depended primarily upon cortisol abnormalities, which increased an individual's discontinuation risk by 7.7-fold. These findings support admission screening with the ASI/cortisol for drop out, and stress/drug-use indices for engagement that together may enable clinically-relevant early recognition and interventions for prevention of stress-induced relapse in opioid-dependent populations.

Interventions for female drug-using offenders

BACKGROUND

This is an updated version of a Cochrane review first published in Issue 3, 2006 (Perry 2006). The review represents one in a family of four reviews focusing on the effectiveness of interventions in reducing drug use and criminal activity for offenders. This specific review considers interventions for female drug-using offenders.

OBJECTIVES

To assess the effectiveness of interventions for female drug-using offenders in reducing criminal activity or drug use, or both.

SEARCH METHODS

We searched 14 electronic bibliographic databases (between 2004 and 21st March 2013) and five additional web resources (between 2004 and November 2011). We contacted experts in the field for further information.

SELECTION CRITERIA

We include randomised controlled trials designed to reduce, eliminate or prevent relapse in female drug-using offenders. We also report data on the cost and cost effectiveness of interventions.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by the Cochrane Collaboration.

MAIN RESULTS

We identified 76 trials across the four reviews. Following a process of prescreening, we judged that 11 trials met the inclusion criteria of the specified review; four of the 11 trials are awaiting classification in the review. The remaining seven trials cover 1236 participants. The interventions included in this review report on therapeutic communities (TCs), gender-responsive treatment (GRT), use of case management and cognitive skills, and a pharmacological intervention using buprenorphine. Trial quality and risks of bias varied across each study. The majority of studies were rated as being at 'unclear' risk of bias due to a lack of descriptive information. Overall the interventions showed statistically significant reductions in self-reported drug use, (four studies, 734 participants, risk ratio (RR) 0.68; 95% confidence interval (CI) 0.58 to 0.80) and re-incarceration, (four studies, 745 participants, RR 0.55; 95% CI 0.41 to 0.72). We found a statistically non-significant result for re-arrest (three studies, 803 participants, RR 0.80; 95% CI 0.53 to 1.19). Individual treatment results found that TCs and a GRT programme showed a statistically significant reduction in re-incarceration (one study, 509 participants, RR 0.42; 95% CI 0.29 to 0.60) but not for re-arrest, (one study, 314 participants, RR 0.73; 95% CI 0.52 to 1.03) and self-reported drug use (two studies, 825 participants, RR 0.47; 95% CI 0.14 to 1.53). Case management and cognitive skills programmes did not significantly reduce re-arrests, (one study, 183 participants RR 1.12; 95% CI 0.89 to 1.41) or self-reported drug use, (one study, 77 participants, RR 0.65; 95% CI 0.20 to 2.12), but did show a statistically significant reduction in re-incarceration, (three studies, 236 participants, RR 0.63; 95% CI 0.49 to 0.81). Buprenorphine did not significantly reduce self-reported drug use (RR 0.58; 95% CI 0.25 to 1.35), but this result came from a single study with only 36 participants. Due to the small number of studies we were unable to analyse the impact of treatment setting on outcome. No cost and cost effectiveness evidence was reported in the studies.

AUTHORS' CONCLUSIONS

The seven trials show some positive results for the use of treatments to reduce self-reported drug use and subsequent re-incarceration. However, the studies overall showed a high degree of statistical variation, requiring a degree of caution in the interpretation of the magnitude of effect and direction of benefit for treatment outcomes. Descriptions of treatment modalities are required to identify the important elements for treatment success in drug-using female offenders. More trials are required to increase the confidence with which we can draw conclusions about the effectiveness of treatments for female drug-using offenders.

Pharmacological interventions for drug-using offenders

BACKGROUND

The review represents one in a family of four reviews focusing on a range of different interventions for drug-using offenders. This specific review considers pharmacological interventions aimed at reducing drug use and/or criminal activity for illicit drug-using offenders.

OBJECTIVES

To assess the effectiveness of pharmacological interventions for drug-using offenders in reducing criminal activity and/or drug use.

SEARCH METHODS

Fourteen electronic bibliographic databases (searched between 2004 and 21 March 2013) and five additional Web resources (searched between 2004 and 11 November 2011) were searched. Experts in the field were contacted for further information.

SELECTION CRITERIA

Randomised controlled trials assessing the efficacy of any pharmacological interventions for reducing, eliminating or preventing relapse in drug-using offenders were included. Data on the cost and cost-effectiveness of interventions were reported.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by The Cochrane Collaboration.

MAIN RESULTS

A total of 76 trials across the four reviews were identified. After a process of prescreening had been completed, 17 trials were judged to meet the inclusion criteria for this specific review (six of the 17 trials are awaiting classification for the review). The remaining 11 trials contained a total of 2,678 participants. Nine of the eleven studies used samples with a majority of men. The interventions (buprenorphine, methadone and naltrexone) were compared to non pharmacological treatments (e.g., counselling) and other pharmacological drugs. The methodological trial quality was poorly described, and most studies were rated as 'unclear' by the reviewers. The biggest threats to risk of bias were generated through blinding (performance and detection bias) and incomplete outcome data (attrition bias). When combined, the results suggest that pharmacological interventions do significantly reduce subsequent drug use using biological measures, (three studies, 300 participants, RR 0.71 (95% CI 0.52 to 0.97)), self report dichotomous data (three studies, 317 participants, RR 0.42, (95% CI 0.22 to 0.81)) and continuous measures (one study, MD -59.66 (95% CI -120.60 to 1.28)) . In the subgroups analysis for community setting, (two studies, 99 participants: RR 0.62 (95% CI 0.35 to 1.09)) and for secure establishment setting, (one study, 201 participants: RR 0.76 (95% CI 0.52 to 1.10)), the results are no longer statistically significant. Criminal activity was significantly reduced favouring the dichotomous measures of re arrest, (one study, 62 participants, RR 0.60 (95% CI 0.32 to 1.14)), re-incarceration, (three studies, 142 participants, RR 0.33 (95% CI 0.19 to 0.56)) and continuous measures (one study, 51 participants, MD -74.21 (95% CI -133.53 to -14.89)). Findings on the effects of individual pharmacological interventions on drug use and criminal activity show mixed results. Buprenorphine in comparison to a non pharmacological treatment seemed to favour buprenorphine but not significantly with self report drug use, (one study, 36 participants, RR 0.58 (95% CI 0.25 to 1.35)). Methadone and cognitive behavioural skills in comparison to standard psychiatric services, did show a significant reduction for self report dichotomous drug use (one study, 253 participants, RR 0.43 (95% CI 0.33 to 0.56)) but not for self report continuous data (one study 51 participants) MD -0.52 (95% CI -1.09 to 0.05)), or re incarceration RR 1.23 (95% CI 0.53 to 2.87)). Naltrexone was favoured significantly over routine parole and probation for re incarceration (two studies 114 participants, RR 0.36 (95% CI 0.19 to 0.69)) but no data was available on drug use. Finally, we compared each pharmacological treatment to another. In each case we compared methadone to: buprenorphine, diamorphine and naltrexone. No significant differences were displayed for either treatment for self report dichotomous drug use (one study, 193 participants RR 1.23 (95% CI 0.86 to 1.76)), continuous measures of drug use MD 0.70 (95% CI -5.33 to 6.73) or criminal activity RR 1.25 (95% CI 0.83 to 1.88)) between methadone and buprenorphine. Similiar results were found for comparisons with Diamorphine with no significant differences between the drugs for self report dichotomous drug use for arrest (one study, 825 participants RR 1.25 (95% CI 1.03-1.51)) or Naltrexone for dichotomous measures of re incarceration (one study, 44 participants, RR 1.10 (95% CI 0.37 to 3.26)), and continuous outcome measure of crime MD -0.50 (95% CI -8.04 to 7.04)) or self report drug use MD 4.60 (95% CI -3.54 to 12.74)).

AUTHORS' CONCLUSIONS

Pharmacological interventions for drug-using offenders do appear to reduce overall subsequent drug use and criminal activity (but to a lesser extent). No statistically significant differences were displayed by treatment setting. Individual differences are displayed between the three pharmacological interventions (buprenorphine, methadone and naltrexone) when compared to a non pharmacological intervention, but not when compared to each other. Caution should be taken when interpreting these findings, as the conclusions are based on a small number of trials, and generalisation of these study findings should be limited mainly to male adult offenders. Additionally, many studies were rated at high risk of bias because trial information was inadequately described.

Mechanism of autoinduction of methadone N-demethylation in human hepatocytes

BACKGROUND

There is considerable interindividual and intraindividual variability in methadone metabolism and clearance. Methadone dosing is particularly challenging during initiation of therapy, because of time-dependent increases in hepatic clearance (autoinduction). Although methadone N-demethylation is catalyzed in vitro by cytochrome P4502B6 (CYP2B6) and CYP3A4, and clearance in vivo depends on CYP2B6, mechanism(s) of autoinduction are incompletely understood. In this investigation, we determined mechanism(s) of methadone autoinduction using human hepatocytes.

METHODS

Fresh human hepatocytes were exposed to 0.1 to 10 µM methadone for 72 hours. Cells were washed and methadone N-demethylation assessed. CYP2B6, CYP3A4, and CYP3A5 messenger RNA (mRNA), protein expression (by gel-free high-performance liquid chromatography mass spectrometry) and catalytic activity (bupropion hydroxylation and alfentanil dealkylation for CYP2B6 and CYP3A4/5, respectively) were measured. Mechanisms of CYP induction were characterized using pregnane X receptor and constitutive androstane receptor reporter gene assays.

RESULTS

Methadone (10 µM) increased methadone N-demethylation 2-fold, CYP2B6 and CYP3A4 mRNA 3-fold, and protein expression 2-fold. CYP3A5 mRNA was unchanged. CYP2B6 and CYP3A4/5 activities increased 2-fold. Induction by methadone enantiomers (R-methadone versus S-methadone) did not differ. Induction was relatively weak compared with maximum induction by phenobarbital and rifampin. Lower methadone concentrations had smaller effects. Methadone was an agonist for the pregnane X receptor but not the constitutive androstane receptor.

CONCLUSIONS

Methadone caused concentration-dependent autoinduction of methadone N-demethylation in human hepatocytes, related to induction of CYP2B6 and CYP3A4 mRNA expression, protein expression, and catalytic activity. Induction was related to pregnane X receptor but not constitutive androstane receptor activation. These in vitro findings provide mechanistic insights into clinical autoinduction of methadone metabolism and clearance.

BAP updated guidelines: evidence-based guidelines for the pharmacological management of substance abuse, harmful use, addiction and comorbidity: recommendations from BAP

The British Association for Psychopharmacology guidelines for the treatment of substance abuse, harmful use, addiction and comorbidity with psychiatric disorders primarily focus on their pharmacological management. They are based explicitly on the available evidence and presented as recommendations to aid clinical decision making for practitioners alongside a detailed review of the evidence. A consensus meeting, involving experts in the treatment of these disorders, reviewed key areas and considered the strength of the evidence and clinical implications. The guidelines were drawn up after feedback from participants. The guidelines primarily cover the pharmacological management of withdrawal, short- and long-term substitution, maintenance of abstinence and prevention of complications, where appropriate, for substance abuse or harmful use or addiction as well management in pregnancy, comorbidity with psychiatric disorders and in younger and older people.

Post-marketing surveillance of buprenorphine-naloxone in Australia: diversion, injection and adherence with supervised dosing

BACKGROUND

These studies compared the diversion and injection of buprenorphine-naloxone (BNX), buprenorphine (BPN) and methadone (MET) in Australia.

METHODS

Surveys were conducted with regular injecting drug users (IDUs) (2004-2009, N=881-943), opioid substitution treatment (OST) clients (2008, N=440) and authorised OST prescribers (2007, N=291). Key outcome measures include the unsanctioned removal of supervised doses, diversion, injection, motivations, drug liking and street price. Levels of injection among IDUs were adjusted for background availability of medications. Doses not taken as directed by OST clients were adjusted by total number of daily doses dispensed.

RESULTS

Among regular IDUs, levels of injection were lower for BNX relative to BPN, but comparable to those for MET, adjusting for background availability. Among OST clients, fewer BNX clients (13%) reported recently injecting their medication, than BPN (28%) and MET clients (23%). Fewer MET clients (10%) reported removal of supervised doses, than BPN (35%) and BNX clients (22%). There were no differences in prevalence of recent diversion (28% of all OST clients). Adjusting for the total doses dispensed, more BPN was injected (10%), removed (12%) and diverted (5%), than MET (5%, <1% and 2% respectively) and BNX (5%, 9% and <1% respectively). In 2009, the median street price of BNX was equivalent to that for BPN.

CONCLUSIONS

BNX was less commonly and less frequently injected than BPN, but both sublingual medications were diverted more than liquid MET.

Pharmacological enhancement of naltrexone treatment for opioid dependence: a review

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

Prospective comparative assessment of buprenorphine overdose with heroin and methadone: clinical characteristics and response to antidotal treatment

Buprenorphine is a partial opioid agonist with a "ceiling effect" for respiratory depression. Despite this, it has been associated with severe overdoses. Conflicting data exist regarding its response in overdose to naloxone. We compared clinical overdose characteristics of buprenorphine with heroin and methadone and assessed responses to naloxone and flumazenil. Patients admitted to two intensive care units with severe opioid overdoses were enrolled into this 4-year prospective study. Urine and blood toxicological screening were performed to identify overdoses involving predominantly buprenorphine, heroin, or methadone. Eighty-four patients with heroin (n = 26), buprenorphine (n = 39), or methadone (n = 19) overdoses were analyzed. In the buprenorphine group, sedative drug coingestions were frequent (95%), whereas in the methadone group, suicide attempts were significantly more often reported (p = .0007). Buprenorphine overdose induced an opioid syndrome not differing significantly from heroin and methadone in mental status (as measured by Glasgow Coma Score) or arterial blood gases. Mental status depression was not reversed in buprenorphine overdoses with naloxone (0.4-0.8 mg) but did improve with flumazenil (0.2-1 mg) if benzodiazepines were coingested. In conclusion, buprenorphine overdose causes an opioid syndrome clinically indistinguishable from heroin and methadone. Although mental status and respiratory depression are often unresponsive to low-dose naloxone, flumazenil may be effective in buprenorphine overdoses involving benzodiazepines.

The Australian Illicit Drug Reporting System: Monitoring Trends in Illicit Drug Availability, Use and Drug-Related Harm in Australia 1996–2006

We describe trends in illicit drug use revealed by the Australian Illicit Drug Reporting System (IDRS) between 1996 and 2006. We begin by briefly outlining the rationale, development, and testing of the IDRS, which integrates information from: interviews with a sentinel population of injecting drug users (IDU); key experts in health and law enforcement; and indicators that include information on drug purity and price, plus indicators of drug-related harm, such as fatal and nonfatal overdoses. These sources of information are critically discussed at annual meetings of researchers, policy makers and practitioners in the field. We describe what the IDRS has revealed about the use of heroin, cocaine, methamphetamines, and injected pharmaceutical preparations (opioids and benzodiazepines) over the period 1996–2006. We also illustrate how IDRS data can be combined with pharmaceutical prescription data to evaluate the effectiveness of policies designed to reduce benzodiazepine injecting. We also very briefly describe recent experience with monitoring trends on “dance party” drug use that extends the methods of IDRS by combining data from interviews with party drug users, key experts, and leading indicators of drug use.

Endogenous opiates and behavior: 2007

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

Exposure to opioid maintenance treatment reduces long-term mortality

AIMS

To (i) examine the predictors of mortality in a randomized study of methadone versus buprenorphine maintenance treatment; (ii) compare the survival experience of the randomized subject groups; and (iii) describe the causes of death.

DESIGN

Ten-year longitudinal follow-up of mortality among participants in a randomized trial of methadone versus buprenorphine maintenance treatment.

SETTING

Recruitment through three clinics for a randomized trial of buprenorphine versus methadone maintenance.

PARTICIPANTS

A total of 405 heroin-dependent (DSM-IV) participants aged 18 years and above who consented to participate in original study.

MEASUREMENTS

Baseline data from original randomized study; dates and causes of death through data linkage with Births, Deaths and Marriages registries; and longitudinal treatment exposure via State health departments. Predictors of mortality examined through survival analysis.

FINDINGS

There was an overall mortality rate of 8.84 deaths per 1000 person-years of follow-up and causes of death were comparable with the literature. Increased exposure to episodes of opioid treatment longer than 7 days reduced the risk of mortality; there was no differential mortality among methadone versus buprenorphine participants. More dependent, heavier users of heroin at baseline had a lower risk of death, and also higher exposure to opioid treatment. Older participants randomized to buprenorphine treatment had significantly improved survival. Aboriginal or Torres Strait Islander participants had a higher risk of death.

CONCLUSIONS

Increased exposure to opioid maintenance treatment reduces the risk of death in opioid-dependent people. There was no differential reduction between buprenorphine and methadone. Previous studies suggesting differential effects may have been affected by biases in patient selection.

Opioid overdose deaths can occur in patients with naltrexone implants

From Australian coronial records, we identified five deaths involving implantable naltrexone between 2000 and 2004. One man died from acute narcotism with a naltrexone implant in place and a blood naltrexone level of 0.3 mg/L. A woman died of combined drug effect (including naltrexone) accompanied by severe pain from a naltrexone implant site. These cases indicate that patients can die from opioid overdose with a naltrexone implant and blood naltrexone levels higher than reported blockade levels.