The future of precision medicine in opioid use disorder: inclusion of patient-important outcomes in clinical trials

Opioid use has reached an epidemic proportion in Canada and the United States that is mostly attributed to excess availability of prescribed opioids for pain. This excess in opioid use led to an increase in the prevalence of opioid use disorder (OUD) requiring treatment. The most common treatment recommendations include medication-assisted treatment (MAT) combined with psychosocial interventions. Clinical trials investigating the effectiveness of MAT, however, have a limited focus on effectiveness measures that overlook patient-important outcomes. Despite MAT, patients with OUD continue to suffer negative consequences of opioid use. Patient goals and personalized medicine are overlooked in clinical trials and guidelines, thus missing an opportunity to improve prognosis of OUD by considering precision medicine in addiction trials. In this mixed-methods study, patients with OUD receiving MAT (n=2,031, mean age 39.1 years [SD 10.7], 44% female) were interviewed to identify patient goals for MAT. The most frequently reported patient-important outcomes were to stop treatment (39%) and to avoid all drugs (25%). These results are inconsistent with treatment recommendations and trial outcome measures. We discuss theses inconsistencies and make recommendations to incorporate these outcomes to achieve patient-centered and personalized treatment strategies.

The association between nicotine dependence and physical health among people receiving injectable diacetylmorphine or hydromorphone for the treatment of chronic opioid use disorder.

INTRODUCTION: People with chronic opioid use disorder often present to treatment with individual and structural vulnerabilities and remain at risk of reporting adverse health outcomes. This risk is greatly compounded by tobacco smoking, which is highly prevalent among people with chronic opioid use disorder. Despite the known burden of tobacco smoking on health, the relationship between nicotine dependence and health has not been studied among those receiving injectable opioid agonist treatment. As such, the present study aims to explore the association between nicotine dependence and physical health among participants of the Study to Assess Longer-Term Opioid Medication Effectiveness (SALOME) at baseline and six-months. METHODS: SALOME was a double-blind phase III clinical trial testing the non-inferiority of injectable hydromorphone to injectable diacetylmorphine for chronic opioid use disorder. Participants reporting tobacco smoking were included in a linear regression analysis of physical health at baseline (before receiving treatment) and at six-months. RESULTS: At baseline, nicotine dependence score, lifetime history of emotional, physical, or sexual abuse and prior month safe injection site access were independently and significantly associated with physical health. At six-months nicotine dependence score was the only variable that maintained this significant and independent association with physical health. CONCLUSIONS: Findings indicate that after six-months, the injectable treatment effectively brought equity to patients' physical health status, yet the association with nicotine dependence remained. Findings could inform whether the provision of treatment for nicotine dependence should be made a priority in settings where injectable opioid agonist treatment is delivered to achieve improvements in overall physical health in this population.

Safety profile of injectable hydromorphone and diacetylmorphine for long-term severe opioid use disorder.

AIMS: To review the safety profile of injectable hydromorphone and diacetylmorphine and explore if adverse events (AEs) or serious adverse events (SAEs) were associated with dose and patterns of attendance. METHODS: This was a non-inferiority randomized double-blind controlled trial (Vancouver, Canada) testing hydromorphone (n=100) and diacetylmorphine (n=102) for the treatment of severe opioid use disorder. Medications were delivered under the supervision of trained Registered Nurses up to three times daily. AEs were described using MedDRA codes. RESULTS: Most common related AEs included immediate post-injection reaction or injection site pruritus reactions, somnolence and opioid overdoses. Adjusted analysis indicated that participants in the hydromorphone group were less likely to have any related AE or SAE compared to the diacetylmorphine group. Related somnolence and opioid overdose events were distributed throughout the six months treatment period. In the diacetylmorphine group, five of the eleven related SAE opioid overdoses (requiring naloxone) occurred in the first 30days since most recent treatment initiation. Analysis of somnolence and opioid overdose (AEs and SAEs) event rates by received dose suggested a non-linear relationship. However, in the diacetylmorphine group higher event rates per person days were recorded at lower doses. CONCLUSIONS: When injectable hydromorphone and diacetylmorphine are individually dosed and monitored, their opioid-related side effects, including potential fatal overdoses, are safely mitigated and treated by health care providers. In the midst of an opioid overdose epidemic, injectable options are timely to reach a very important minority of people who inject street opioids and are not attracted to other treatments.

Association between cannabis use and methadone maintenance treatment outcomes: an investigation into sex differences.

BACKGROUND: Cannabis will soon become legalized in Canada, and it is currently unclear how this will impact public health. Methadone maintenance treatment (MMT) is the most common pharmacological treatment for opioid use disorder (OUD), and despite its documented effectiveness, a large number of patients respond poorly and experience relapse to illicit opioids. Some studies implicate cannabis use as a risk factor for poor MMT response. Although it is well established that substance-use behaviors differ by sex, few of these studies have considered sex as a potential moderator. The current study aims to investigate sex differences in the association between cannabis use and illicit opioid use in a cohort of MMT patients. METHODS: This multicentre study recruited participants on MMT for OUD from Canadian Addiction Treatment Centre sites in Ontario, Canada. Sex differences in the association between any cannabis use and illicit opioid use were investigated using multivariable logistic regression. A secondary analysis was conducted to investigate the association with heaviness of cannabis use. RESULTS: The study included 414 men and 363 women with OUD receiving MMT. Cannabis use was significantly associated with illicit opioid use in women only (OR = 1.82, 95% CI 1.18, 2.82, p = 0.007). Heaviness of cannabis use was not associated with illicit opioid use in men or women. CONCLUSIONS: This is the largest study to date examining the association between cannabis use and illicit opioid use. Cannabis use may be a sex-specific predictor of poor response to MMT, such that women are more likely to use illicit opioids if they also use cannabis during treatment. Women may show improved treatment outcomes if cannabis use is addressed during MMT.

The association between age of onset of opioid use and comorbidity among opioid dependent patients receiving methadone maintenance therapy.

BACKGROUND: Opioid use disorder (OUD) affects approximately 21.9 million people worldwide. This study aims to determine the association between age of onset of opioid use and comorbid disorders, both physical and psychiatric, in patients receiving methadone maintenance treatment (MMT) for OUD. Understanding this association may inform clinical practice about important prognostic factors of patients on MMT, enabling clinicians to identify high-risk patients. METHODS: This study includes data collected between June 2011 and August 2016 for the Genetics of Opioid Addiction research collaborative between McMaster University and the Canadian Addiction Treatment Centers. All patients were interviewed by trained health professionals using the Mini-International Neuropsychiatric Interview and case report forms. Physical comorbidities were verified using patients' electronic medical records. A multi-variable logistic regression model was constructed to determine the strength of the association between age of onset of opioid use and the presence of physical or psychiatric comorbidity while adjusting for current age, sex, body mass index, methadone dose and smoking status. RESULTS: Data from 627 MMT patients with a mean age of 38.8 years (SD = 11.07) were analyzed. Individuals with an age of onset of opioid use younger than 18 years were found to be at higher odds for having a physical or psychiatric comorbid disorder compared to individuals with an age of onset of opioid use of 31 years or older (odds ratio 2.94, 95% confidence interval 1.20, 7.19, p = 0.02). A significant association was not found between the risk of having a comorbidity and an age of onset of opioid use between 18 and 25 years or 26 and 30 years, compared to an age of onset of opioid use of 31 years or older. CONCLUSION: Our study demonstrates that the younger one begins to use opioids, the greater their chance of having a physical or psychiatric co-morbidity. Understanding the risk posed by an earlier onset of opioid use for the later development of comorbid disorders informs clinical practice about important prognostic predictors and aids in the identification of high-risk patients.

Hydromorphone Compared With Diacetylmorphine for Long-term Opioid Dependence: A Randomized Clinical Trial.

IMPORTANCE: Diacetylmorphine hydrochloride (the active ingredient in heroin), delivered under supervision, is effective for the treatment of severe opioid use disorder. However, owing to political and regulatory barriers, it is not available in many settings around the world, which limits the options for many long-term street opioid injectors not attracted into or retained in available treatments. OBJECTIVE: To test if injectable hydromorphone hydrochloride is noninferior to injectable diacetylmorphine in reducing illicit heroin use for chronic injection opioid users after 6 months of intervention. DESIGN, SETTING, AND PARTICIPANTS: The Study to Assess Longer-term Opioid Medication Effectiveness (SALOME) was a phase 3, double-blind, noninferiority trial. The study randomized 202 long-term street opioid injectors in Vancouver, British Columbia, Canada. Eligible participants were recruited between December 19, 2011, and December 18, 2013. Both intent-to-treat (ITT) and per-protocol (PP) analyses were conducted. INTERVENTIONS: Participants were randomly assigned to receive injectable diacetylmorphine or hydromorphone (up to 3 times daily) for 6 months under supervision. MAIN OUTCOMES AND MEASURES: Primary and coprimary efficacy outcomes were self-reported days of street heroin use (primary), days of any street-acquired opioids in the prior 30 days (noninferiority margin, 4 days), and the proportion of urinalyses positive for street heroin markers (margin, 10% of the observed rate in the diacetylmorphine group). The mean differences between diacetylmorphine and hydromorphone for the ITT and PP analyses were reported. RESULTS: The study included 202 participants; 100 randomized to receive hydromorphone and 102 to diacetylmorphine. Their mean (SD) age was 44.33 (9.63) years, and 30.7% (62 of 202) were women. Noninferiority of hydromorphone was confirmed in the PP analysis (-1.44; 90% CI, -3.22 to 0.27) for street heroin use, although the margin of 4 days was not excluded in the ITT analysis (-2.34; 90% CI, -4.14 to -0.52). Noninferiority was confirmed for any street opioids in the ITT analysis (-0.85; 90% CI, -2.97 to 1.25) and the PP analysis (-0.15; 90% CI, -2.09 to 1.76), as well as for the urinalyses (0.09; 90% CI, -0.02 to 0.19 for the ITT analysis and 0.13; 90% CI, 0.02-0.24 for the PP analysis). There were 29 SAEs considered to have some relationship with the injection medication, 5 in the hydromorphone group and 24 in the diacetylmorphine group (rate ratio, 0.21; 95% CI, 0.06-0.69). Seizures and overdoses accounted for 25 of the 29 related SAEs. CONCLUSIONS AND RELEVANCE: This study provides evidence to suggest noninferiority of injectable hydromorphone relative to diacetylmorphine for long-term opioid dependence. In jurisdictions where diacetylmorphine is currently not available or for patients in whom it is contraindicated or unsuccessful, hydromorphone could be offered as an alternative. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01447212.

Sex differences in substance use, health, and social functioning among opioid users receiving methadone treatment: a multicenter cohort study.

BACKGROUND: Despite the growing numbers of men and women with opioid use disorder in Canada, sex-specific issues in treatment have not been re-examined in the current population of patients with opioid addiction. We aimed to evaluate sex differences in substance use, health, and social functioning among men and women currently receiving methadone treatment for opioid use disorder in Ontario, Canada. METHODS: We recruited 503 participants with opioid dependence disorder receiving methadone maintenance treatment. We collected data on demographics, treatment characteristics, psychiatric history, addiction severity, and drug use patterns through urinalysis. We performed adjusted univariate analyses and logistic regression to identify distinct factors affecting men and women. RESULTS: Among our sample of 54 % (n = 266) men and 46 % women (n = 226) with mean age 38.3 years, less than half of participants were employed (35.6 %) and married (31.8 %) and had completed a high school education (27.9 %). Compared to men, women had frequent physical and psychological health problems, family history of psychiatric illness, and childcare responsibilities and began using opioids through a physician prescription. Men had higher rates of employment, cigarette smoking, and cannabis use compared to women. CONCLUSIONS: Our results have revealed different patterns of substance use, health, and social functioning among men and women currently receiving methadone treatment for opioid addiction in Ontario, Canada. This information can be used to develop an integrative treatment regimen that caters to the individual needs of men and women, as well as to inform methadone treatment protocols to include specialized services (including vocational counseling, childcare and parenting assistance, medical assistance, relationship or domestic violence counseling, etc.) and increase their availability and accessibility on a larger scale.

Impact of Chronic Pain on Treatment Prognosis for Patients with Opioid Use Disorder: A Systematic Review and Meta-analysis.

BACKGROUND: While a number of pharmacological interventions exist for the treatment of opioid use disorder, evidence evaluating the effect of pain on substance use behavior, attrition rate, and physical or mental health among these therapies has not been well established. We aim to evaluate these effects using evidence gathered from a systematic review of studies evaluating chronic non-cancer pain (CNCP) in patients with opioid use disorder. METHODS: We searched the Medline, EMBASE, PubMed, PsycINFO, Web of Science, Cochrane Database of Systematic Reviews, ProQuest Dissertations and theses Database, Cochrane Central Register of Controlled Trials, World Health Organization International Clinical Trials Registry Platform Search Portal, and National Institutes for Health Clinical Trials Registry databases to identify articles evaluating the impact of pain on addiction treatment outcomes for patients maintained on opioid agonist therapy. RESULTS: Upon screening 3,540 articles, 14 studies with a combined sample of 3,128 patients fulfilled the review inclusion criteria. Results from the meta-analysis suggest that pain has no effect on illicit opioid consumption [pooled odds ratio (pOR): 0.70, 95%CI 0.41-1.17; I (2) = 0.0] but a protective effect for reducing illicit non-opioid substance use (pOR: 0.57, 95%CI 0.41-0.79; I (2) = 0.0). Studies evaluating illicit opioid consumption using other measures demonstrate pain to increase the risk for opioid abuse. Pain is significantly associated with the presence of psychiatric disorders (pOR: 2.18; 95%CI 1.6, 2.9; I (2) = 0.0%). CONCLUSION: CNCP may increase risk for continued opioid abuse and poor psychiatric functioning. Qualitative synthesis of the findings suggests that major methodological differences in the design and measurement of pain and treatment response outcomes are likely impacting the effect estimates.

Predictors of non-use of illicit heroin in opioid injection maintenance treatment of long-term heroin dependence.

AIMS: To investigate baseline and concurrent predictors of non-use of illicit heroin among participants randomized to injectable opioids in the North American Opiate Medication Initiative (NAOMI) clinical trial. METHODS: NAOMI was an open-label randomized controlled trial comparing the effectiveness of injectable diacetylmorphine and hydromorphone for long-term opioid-dependency. Outcomes were assessed at baseline and during treatment (3, 6, 9, 12months). Days of non-use of illicit heroin in the prior month at each follow-up visit were divided into three categories: Non-use; Low use (1 to 7days) and High use (8days or more). Tested covariates were: Sociodemographics, Health, Treatment, Drug use and illegal activities. Mixed-effect proportional odds models with random intercept for longitudinal ordinal outcomes were used to assess the predictors of the non-use of illicit heroin. RESULTS: 139 participants were included in the present analysis. At each follow-up visit, those with non-use of illicit heroin represented 47.5% to 54.0% of the sample. Fewer days of cocaine use (p=0.074), fewer days engaged in illegal activities at baseline (p<0.01) and at each visit (p<0.01), less money spent on drugs (p<0.001), days with injection opioid or oral methadone treatment (p<0.001) and total mg of injectable opioids taken (p<0.001), independently predicted lower use of illicit heroin. CONCLUSIONS: The independent effect of several concurrent factors besides the injection of opioid dose suggests benefits from the clinic that go beyond the provision of the medication alone. Thus, this supervised model of care presents an opportunity to maximize the beneficial impact of medical and psychosocial components of the treatment on improving outcomes associated with non-use of illicit heroin.

Evaluation of clinical and inflammatory profile in opioid addiction patients with comorbid pain: results from a multicenter investigation.

BACKGROUND: Chronic pain is the most commonly reported comorbidity among patients with opioid addiction receiving methadone maintenance treatment (MMT), with an estimated prevalence ranging between 30% and 55%. Evidence suggests that patients with comorbid pain are at high risk for poor treatment response, including continued illicit substance use. Due to the important relationship between the presence of pain and illicit substance abuse within the MMT setting, it is imperative that we target our efforts toward understanding the characteristics of this patient population. METHODS: The primary objective of this study was to explore the clinical and inflammatory profile of MMT patients reporting comorbid pain. This multicenter study enrolled patients (n=235) on MMT for the treatment of opioid dependence. Clinical history and blood and urine data were collected. Blood samples were obtained for estimating the serum levels of inflammatory markers (tumor necrosis factor [TNF]-α, interleukin-1 receptor antagonist [IL-1ra], IL-6, IL-8, IL-10, interferon [IFN]-γ and chemokine (C-C motif) ligand 2 [CCL2]). The study objectives were addressed using a descriptive statistical summary and a multivariable logistic regression model constructed in STATA version 12. RESULTS: Among the participants eligible for inclusion (n=235), serum IFN-γ level and substance abuse behavior proved to be important delineating characteristics for the detection of comorbid pain. Analysis of inflammatory profile showed IFN-γ to be significantly elevated among patients reporting comorbid pain (odds ratio [OR]: 2.02; 95% confidence interval [CI]: 1.17, 3.50; P=0.01). Patients reporting comorbid pain were also found to have an increase in positive opioid urine screens (OR: 1.02; 95% CI: 1.00, 1.03; P=0.01), indicating an increase in illicit opioid consumption. CONCLUSION: MMT patients with comorbid pain were shown to have elevated IFN-γ and higher rates of continued opioid abuse. The ability to objectively distinguish between patients with comorbid pain may help to both improve the prediction of poor responders to MMT as well as identify treatment approaches such as anti-inflammatory medications as safe alternatives for MMT patients with comorbid pain.

Problems with the identification of 'problematic' cannabis use: examining the issues of frequency, quantity, and drug use environment.

Considerable recent attention has focused on how harmful or problematic cannabis use is defined and understood in the literature and put to use in clinical practice. The aim of the current study is to review conceptual and measurement shortcomings in the identification of problematic cannabis use, drawing on the WHO ASSIST instrument for specific examples. Three issues with the current approach are debated and discussed: (1) the identification of problematic cannabis use disproportionately relies on measures of the frequency of cannabis consumption rather than the harms experienced; (2) the quantity consumed on a typical day is not considered when assessing problematic use, and (3) screening tools for problematic use employ a 'one-size-fits-all approach' and fail to reflect on the drug use context (networks and environment). Our commentary tackles each issue, with a review of relevant literature coupled with analyses of two Canadian data sources--a representative sample of the Canadian adult population and a smaller sample of adult, regular, long-term cannabis users from four Canadian cities--to further articulate each point. This article concludes with a discussion of appropriate treatment interventions and approaches to reduce cannabis-related harms, and offers suggested changes to improve the measurement of problematic cannabis use.

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

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

Transforming health professional education through social accountability: Canada's Northern Ontario School of Medicine.

BACKGROUND: The Northern Ontario School of Medicine (NOSM) has a social accountability mandate to contribute to improving the health of the people and communities of Northern Ontario. NOSM recruits students from Northern Ontario or similar backgrounds and provides Distributed Community Engaged Learning in over 70 clinical and community settings located in the region, a vast underserved rural part of Canada. METHODS: NOSM and the Centre for Rural and Northern Health Research (CRaNHR) used mixed methods studies to track NOSM medical learners and dietetic interns, and to assess the socioeconomic impact of NOSM. RESULTS: Ninety-one percent of all MD students come from Northern Ontario with substantial inclusion of Aboriginal (7%) and Francophone (22%) students. Sixty-one percent of MD graduates have chosen family practice (predominantly rural) training. The socioeconomic impact of NOSM included new economic activity, more than double the School's budget; enhanced retention and recruitment for the universities and hospital/health services; and a sense of empowerment among community participants attributable in large part to NOSM. DISCUSSION: There are signs that NOSM is successful in graduating health professionals who have the skills and desire to practice in rural/remote communities and that NOSM is having a largely positive socioeconomic impact on Northern Ontario.

History of reported sexual or physical abuse among long-term heroin users and their response to substitution treatment.

Opioid-dependent individuals with a history of abuse have exhibited worse mental and physical health compared to those without such a history; however, the evidence regarding the influence of abuse histories on addiction treatment outcomes are conflicting. In the present study, we identified history of physical or sexual abuse at treatment initiation in relation to drug use and health among long-term opioid-dependent individuals and we determined the relationship of abuse histories with treatment outcomes following substitution treatment. We analyzed data from a randomized controlled trial that compared the effectiveness of opioid-agonists in the treatment of chronic opioid dependence. The North American Opiate Medication Initiative (NAOMI) was conducted in Vancouver and Montreal (Canada) and provided oral methadone, injectable diacetylmorphine or injectable hydromorphone, the last two on a double blind basis, over 12 months. A total of 112 (44.6%) participants reported a history of physical or sexual abuse at baseline. Participants with an abuse history reported a significantly higher number of chronic medical problems, suicide attempts, and previous drug treatments and had poorer psychiatric, family and social relations, and quality of life status compared to those without abuse histories. No differences in current and past substance use were found between those with and without abuse histories. Following 12 months of treatment, the participants with abuse histories improved to a similar degree as those without a history of abuse in all of the European Addiction Severity Index sub-scales, with the exception of medical status. The findings suggest that individuals with abuse histories were able to achieve similar outcomes as those without abuse histories following treatment despite having poorer scores in physical and mental health, social status and quality of life at treatment initiation. These findings suggest that the substitution treatments as provided in this study can benefit the most vulnerable and access needs to be expanded to reach this population.

Characteristics and response to treatment among Aboriginal people receiving heroin-assisted treatment.

BACKGROUND: Medically prescribed diacetylmorphine, the active ingredient of heroin, has been shown to be effective for the treatment of severe opioid addiction. However, there are no data regarding its effectiveness among Aboriginal heroin injectors. METHODS: The present analyses were performed using data from the NAOMI study (North American Opiate Maintenance Initiative), an open-label randomized controlled trial that compared the effectiveness of injectable diacetylmorphine (45.8%) and hydromorphone (10%) vs. oral methadone (44.2%) among long-term treatment-refractory opioid-dependent individuals. Rates of retention and response to treatment were analyzed among participants from the Vancouver site (n = 192). RESULTS: Baseline profiles were similar among Aboriginal (n = 60) and non-Aboriginal (n = 132) participants except for higher HIV positive rates among Aboriginal people (23.3% vs. 8.3%). Among Aboriginal participants in the injection and methadone groups, retention rates at 12 months were 84.4% vs. 57.1% and response rates were 68.8% vs. 53.4%, respectively. Aboriginal and non-Aboriginal rates were not significantly different. DISCUSSION: Offering treatment assisted with medically prescribed diacetylmorphine or hydromorphone to long-term treatment-refractory opioid-dependent Aboriginal people could be an effective way to attract them into and retain them in treatment as well as dramatically reduce the risk of HIV infection.

The effect of motivational status on treatment outcome in the North American Opiate Medication Initiative (NAOMI) study.

Dropout and recidivism from addiction treatment has been found to be associated with individuals' readiness for change. Motivation for treatment among participants entering the North American Opiate Medication Initiative (NAOMI) randomized controlled trial, which compared heroin assisted treatment (HAT) to optimized methadone maintenance treatment (MMT), was assessed. Through multivariate regression, we aimed to determine whether baseline motivational status was predictive of four treatment outcomes: early dropout, 12-month retention, 12-month response to treatment, and time to discontinuation of treatment. Among the 251 out-of-treatment chronic opioid dependent patients recruited in Montreal, Quebec and Vancouver, British Columbia, 52% reported having a high level of motivation for treatment. HAT was statistically significantly more effective than MMT on each of the outcomes assessed. Baseline motivational status did not predict retention or time to discontinuation in either HAT or MMT. However, while patients were retained in HAT regardless of motivational status, motivated patients showed a more favourable response to treatment in terms of decreases in crime and illicit drug use. These results suggest that HAT successfully retains opioid dependent patients who otherwise may not have been attracted into existing treatment options, and may enhance the odds of successful rehabilitation among patients motivated for treatment.

Double-blind injectable hydromorphone versus diacetylmorphine for the treatment of opioid dependence: a pilot study.

Using data from the North American Opioid Maintenance Initiative study, a Phase III randomized and parallel arm trial, this pilot study is aimed at testing if treatment response with injectable hydromorphone differs compared to diacetylmorphine in the treatment of long-term opioid addiction. A total of 140 long-term, treatment-refractory opioid-dependent individuals received either injectable diacetylmorphine (n = 115) or hydromorphone (n = 25), in a double-blind fashion, over 12 months. At the end of the study, none of the participants in the hydromorphone group thought they were definitely receiving this drug. Retention rates at 12 months with diacetylmorphine (87.8%; 95% confidence interval [CI] = 80.5%-92.7%) and hydromorphone (88.0%; 95% CI = 68.7%-96.1%) were virtually identical. The use of illicit heroin in the prior month declined from a mean of 26.6 and 26.3 days at baseline to 5.3 and 5.2 days at 12 month in the diacetylmorphine and hydromorphone groups, respectively. There were no differences between diacetylmorphine and hydromorphone in the adjusted mean scores of the European Addiction Severity Index. There were no differences in the safety profile of the medications. Hydromorphone may be similarly safe and effective as diacetylmorphine as opioid-agonist substitution treatment; future studies are required to confirm it. Further study will also be required to show that open-label hydromorphone can also successfully attract patients into care and retain them.

Diacetylmorphine versus methadone for the treatment of opioid addiction.

BACKGROUND: Studies in Europe have suggested that injectable diacetylmorphine, the active ingredient in heroin, can be an effective adjunctive treatment for chronic, relapsing opioid dependence. METHODS: In an open-label, phase 3, randomized, controlled trial in Canada, we compared injectable diacetylmorphine with oral methadone maintenance therapy in patients with opioid dependence that was refractory to treatment. Long-term users of injectable heroin who had not benefited from at least two previous attempts at treatment for addiction (including at least one methadone treatment) were randomly assigned to receive methadone (111 patients) or diacetylmorphine (115 patients). The primary outcomes, assessed at 12 months, were retention in addiction treatment or drug-free status and a reduction in illicit-drug use or other illegal activity according to the European Addiction Severity Index. RESULTS: The primary outcomes were determined in 95.2% of the participants. On the basis of an intention-to-treat analysis, the rate of retention in addiction treatment in the diacetylmorphine group was 87.8%, as compared with 54.1% in the methadone group (rate ratio for retention, 1.62; 95% confidence interval [CI], 1.35 to 1.95; P<0.001). The reduction in rates of illicit-drug use or other illegal activity was 67.0% in the diacetylmorphine group and 47.7% in the methadone group (rate ratio, 1.40; 95% CI, 1.11 to 1.77; P=0.004). The most common serious adverse events associated with diacetylmorphine injections were overdoses (in 10 patients) and seizures (in 6 patients). CONCLUSIONS: Injectable diacetylmorphine was more effective than oral methadone. Because of a risk of overdoses and seizures, diacetylmorphine maintenance therapy should be delivered in settings where prompt medical intervention is available. (ClinicalTrials.gov number, NCT00175357.)

Proportional hazards frailty models for recurrent methadone maintenance treatment.

The authors' objective in this study was to identify determinants of time to discontinuation of methadone maintenance treatment (MMT) across multiple treatment episodes. Population-level data on drug dispensations for all patients receiving methadone for opioid maintenance throughout the tenure of the British Columbia, Canada, methadone program to date (1996-2007) were extracted from an administrative database. Proportional hazards frailty models were developed to assess factors associated with time to discontinuation from recurrent MMT episodes. A total of 17,005 patients experienced 32,656 treatment episodes over the 11-year follow-up period. Age, medical comorbidity, and physician patient load, as well as neighborhood-level socioeconomic status indicators, were significant predictors of time to discontinuation of treatment; treatment adherence and average daily doses up to and above 120 mg per day were also associated with longer treatment episodes. Studies have shown that while successfully retained in MMT, clients decrease their illicit drug use and criminal activity, and their risk of mortality is substantially lower; however, the majority of clients relapse. Many reenter treatment. The primary finding of this study was that patients experiencing multiple treatment episodes tended to stay in treatment for progressively longer periods in later episodes.

Scientific and political challenges in North America's first randomized controlled trial of heroin-assisted treatment for severe heroin addiction: rationale and design of the NAOMI study.

BACKGROUND: Heroin addiction is a chronic relapsing disease, best treated with opioid-agonist substitution therapy such as methadone maintenance. However, a subset of the most severely affected individuals do not benefit sufficiently from this treatment. The North American Opiate Medication Initiative (NAOMI) is a randomized clinical trial (RCT) to evaluate the hypothesis that pharmaceutical-grade heroin, diacetylmorphine (DAM) is more effective in retaining patients and improving their outcomes than Methadone Maintenance Treatment (MMT) among those with chronic, refractory injection opioid dependence. PURPOSE/METHODS: The study aimed at randomizing 253 participants to two intervention arms: (1) MMT alone or (2) injectable opioids (DAM or hydromorphone) plus adjunctive MMT if deemed appropriate. The planned study duration was 3 years, with a 1-year intake period, 1 year of treatment, and an additional year of follow-up. The NAOMI trial was initiated in March 2005 at two Canadian sites (Vancouver and Montreal). This was the first multicenter RCT in North America to compare the relative efficacy of these different therapeutic strategies. We discuss the rationale behind the NAOMI study design, as well as the scientific and political issues and methodological challenges arising from the conduct of a trial that involves the prescription of a controlled substance to individuals with dependence on that substance. LIMITATIONS: Restrictive entry criteria led to the exclusion of many otherwise eligible participants, slowing recruitment into the study. Inability to offer DAM treatment beyond 12 months led to artificial boundary effects in the trial. CONCLUSIONS: Addiction treatment research navigates between science and politics, and evidence-based medicine is many times confronted by moral beliefs. Political considerations influence study design to a further degree than in RCTs treating less-stigmatized disorders with more-reputable medications.