Determining effective methadone doses for individual opioid-dependent patients

Assessing predictors of adequate individual buprenorphine maintenance dosage for the treatment of opioid use disorder: Listening to the patient

OBJECTIVE

Dose optimization plays a key role in determining clinical outcomes in patients on opioid agonist treatment (OAT). The objective of this study was to identify the variables independently associated with buprenorphine/naloxone (B/N) dose adequacy in patients with opiate use disorder (OUD).

METHOD

Cross-sectional study of a convenience sample of patients with OUD treated with B/N (n = 315) in four regions in Spain. The Opiate Dosage Adequacy Scale (ODAS) was used to determine B/N dose adequacy. The ODAS evaluate the six components of the "dose adequacy" construct, as follows: continued use of heroin; narcotic blockade or crossed tolerance; objective opioid withdrawal symptoms (OWS); subjective OWS; craving for heroin; and overmedication. A binomial logistic regression analysis was performed to identify the variables associated with the condition "ODAS Adequate B/N dose". Participants completed a battery of instruments to assess sociodemographic, substance use, clinical, and treatment variables.

RESULTS

The B/N dose was considered adequate in 231 of the 315 participants (73.3 %). Two variables, satisfaction with B/N as a medication (OR=5.764, 95 % CI=2.211-15.030) and patient-perceived participation in B/N dose decisions (OR=1.790, 95 % CI=1221-2623), were independently, significantly, and positively associated with the "ODAS Adequate B/N dose" condition. While the severity of heroin dependence was significantly associated with buprenorphine dose adequacy in the bivariate analyses, significance was lost in the full regression model.

CONCLUSION

Satisfaction with B/N as a medication and patient-perceived involvement in the dose decision are associated with clinician-assessed dose adequacy. In the context of good clinical practice, it is important to take into account both of these variables to individualize the prescribed dose through a shared decision-making process.

'I went for rehab many times and it never worked, but the harm reduction process has given me renewed hope'. Perceptions on the effectiveness of harm reduction and community-based opioid substitution therapy

ISSUE ADDRESSED

The accessibility of opioid substitution therapy (OST), one of the recommended treatments for opioid dependence, remains low. This study sought to explore the perceived effectiveness of OST from the perspectives of peer outreach workers and OST clients in a community-based harm reduction programme.

METHODS

The research was done within the Community-Oriented Substance Use Programme (COSUP) in Tshwane, South Africa. Fifteen peer educators (13 males and 2 females) took part in two focus group discussions. Thereafter, there were semi-structured interviews in which 15 OST clients (11 males and 4 females) participated. A convenience cross-sectional study was used. Interviews were audio-recorded. Using thematic analysis, themes were examined to evaluate how OST and the harm reduction approach were perceived to contribute to the improved health status of people with opioid dependence.

RESULTS

Peer outreach workers and COSUP clients significantly endorsed OST as an effective treatment for opioid dependence. Participants perceived greater effectiveness of OST compared to abstinence-centred inpatient rehabilitation programmes. However, there were sentiments that more community education on OST was needed to motivate people with opioid dependence to access services and to address misconceptions about OST.

CONCLUSIONS

There is a lack of multi-level and multi-sectoral engagement of various stakeholders in opioid dependence services, needed to accelerate utilisation of OST services. SO WHAT?: The research unpacks the need for an integrated approach to service use optimisation, and the need to evaluate the role that increased awareness and community education on harm reduction strategies can play in enhancing the utilisation of OST services.

Compassionate Care for People with Cancer and Opioid Use Disorder

ABSTRACT

Opioid use disorder (OUD) is an important comorbidity to assess and manage in people with cancer. In this article, the authors discuss strategies for safe opioid management in individuals with OUD and cancer-related pain using a composite case example. They highlight core approaches to pain management, including motivational interviewing, harm reduction, and evidence-based treatments, as well as advocacy for person-centered end-of-life care.

Factors associated with patient perceived suboptimal dosing of in-hospital opioid agonist therapy among people who use illicit drugs in Vancouver, Canada

Optimal dosing of opioid agonist therapy (OAT) is essential for treatment success. However, initiation and maintenance of OAT in hospital settings can be challenging given differing levels of opioid tolerance, withdrawal, and intoxication among patients.

The objective of this study was to characterize the prevalence and factors associated with in-hospital patient perceived suboptimal OAT dosing among people who use illicit drugs (PWUD) in Vancouver, Canada.

Data were derived from three prospective cohorts of PWUD in Vancouver, Canada. Bivariable and multivariable logistic regression models were used to examine factors associated with patient perceived suboptimal in-hospital OAT dose.

273 study participants were prescribed OAT while in hospital: 83 (30.4%) participants perceived their OAT dose to be suboptimal. In a multivariable model, factors positively associated with a perceived suboptimal OAT dose included: homelessness (adjusted odds ratio [AOR] = 2.85; 95% CI: 1.53-5.28), daily stimulant use (AOR = 2.03; 95% CI: 1.14-3.63) and illicit drug use while in hospital (AOR = 2.33; 95% CI: 1.31-4.16).

Almost one third of participants perceived receiving a suboptimal OAT dose while in hospital. These observed correlations indicate that a patient's perception of suboptimal OAT dosing in hospital may be more prevalent for patients who are homeless, report polysubstance use with stimulants and opioids and who obtain illicit drugs while hospitalized. While cautious prescribing of OAT in patients experiencing hospitalization is important, these findings demonstrate a high prevalence of and apparent risk factors for perceived suboptimal OAT dosing.

Psychometric Characteristics of the Persian Version of the Opiate Dosage Adequacy Scale (ODAS)

Introduction

The opiate dosage adequacy scale (ODAS) is one of the most common assessment tools in studies on substance use disorders, which evaluates the "adequacy" of opiate medication doses in individuals recruited in maintenance approaches. There is no investigation on the Persian version of this questionnaire in Iran. This research validated a Persian version of the ODAS.

Methods

The Persian version of the ODAS was translated and revised based on the original scale presented by González-Saiz et al. The psychometric characteristics of the ODAS were assessed via direct interviews. Three trained interviewers questioned 250 patients treated in methadone maintenance clinics in Mazandaran Province (Northern Iran) for more than three months. Internal consistency and factor analysis were conducted using SPSS software, version 24.

Results

The internal consistency of ODAS was satisfactory (Cronbach's α=0.81). Across all items, considerable inter-rater reliability was discovered (kappa values between 0.90 and 1). A four-component structure was produced by the factor analysis that accounted for 77.5% of the total variance. Cronbach's α coefficients of the four components of Heroin craving and overmedication, Consumption, objective opiate withdrawal symptoms, and subjective opiate withdrawal symptoms were 0.84, 0.91, 0.83, and 0.74, respectively.

Conclusion

The reliability and validity of the Persian version of the ODAS were satisfactory in a sample of methadone maintenance subjects.

Highlights

The opiate dosage adequacy scale (ODAS) is a clinical tool for measuring the adequacy of methadone dosesThe Persian version of ODAS has good validity, internal consistency, and inter-rater reliability;The Persian version of the ODAS, as a valid and reliable tool, can be used for the Iranian people under methadone maintenance.

Plain Language Summary

In Iran, opioids are among the most common forms of illicit drugs. In opioid maintenance programs, the adequacy of methadone doses has an important effect on treatment outcomes. Clinicians typically assess the adequacy of doses based on the patient's response to the medication. Different tools are used in clinical studies to evaluate it. One of these tools is the ODAS, developed by González-Saiz et al. In the present study, we validated the Persian version of the ODAS for Iranian patients receiving methadone maintenance programs. The results confirmed the four-factor structure of the Persian ODAS and showed its good internal consistency and inter-rater reliability.

Effects of buprenorphine, methadone, and cariprazine on economic choice between remifentanil and food in squirrel monkeys

We recently reported an economic choice task in which squirrel monkeys chose between differing amounts of remifentanil, a fast-acting opioid, or a food reward to develop a preclinical screen for evaluating potential pharmacotherapies for opioid dependence. Herein, two known opioid addiction treatments are evaluated using this task, as well as a potential new agent, cariprazine, a dopamine D2/D3 receptor partial agonist currently used to treat bipolar disorder and schizophrenia. Preclinical rodent studies suggest this class of compounds may reduce opiate self-administration. Squirrel monkeys were pretreated daily with clinically relevant doses of each compound during the five days of treatment evaluation using the economic choice task. Shifts in drug preference were measured as changes in subjects' indifference values, where the probability of drug and milk choice are equivalent. Buprenorphine produced a significant shift in indifference value between baseline and treatment weeks, indicating a decrease in drug preference. Subjects treated with methadone and cariprazine did not show any significant shift in drug preference. Differences between the buprenorphine and methadone results likely reflect a lack of opioid dependence in the subjects. The cariprazine results suggest that it does not alter opioid reward in non-dependent primates over a five day period.

Association between rs1799971 in the mu opioid receptor gene and methadone maintenance treatment response

OBJECTIVE

Genetic variations can affect individual response to methadone maintenance treatment (MMT) for heroin addiction. The A118G variant (rs1799971) in the mu opioid receptor gene (OPRM1) is a potential candidate single nucleotide polymorphism (SNP) for personalized MMT. This study determined whether rs1799971 is related to MMT response or dose.

METHODS

We recruited 286 MMT patients from a Han Chinese population. The rs1799971 genotype was determined via TaqMan genotyping assay. The genetic effect of this SNP on MMT response or dose was evaluated using logistic regression. A meta-analysis was performed to merge all available data to evaluate the role of rs1799971 in MMT using RevMan 5.3 software.

RESULTS

No statistical significance was observed in the association between the OPRM1 rs1799971 and MMT response or dose in our Chinese cohort. Meta-analysis indicated that the OPRM1 A118G variation was not significantly associated with MMT response or dose requirement.

CONCLUSION

The results suggest that rs1799971 in OPRM1 might not play a critical role alone in influencing MMT response or dose.

Factors associated with 60-day adherence to "safer supply" opioids prescribed under British Columbia's interim clinical guidance for health care providers to support people who use drugs during COVID-19 and the ongoing overdose emergency

AIMS

In March 2020, British Columbia issued Risk Mitigation Guidance (RMG) to support prescribing of pharmaceutical alternatives to illicit drugs, in order to reduce risk for COVID-19, overdose, and withdrawal among people who use drugs. This study evaluated factors associated with 60-day adherence to novel opioid alternatives prescribed at an inner-city health centre in Victoria, Canada.

METHODS

A chart review was conducted to collect data on sociodemographic information, medical histories, and follow-up services among all clients prescribed novel opioid alternatives from March 2020-August 2020 (n = 286). Bivariable and multivariable regression were used to identify independent and adjusted factors associated with 60-day adherence.

RESULTS

Overall, 77% of 286 clients were still receiving opioids after 60 days of follow-up. Medications included hydromorphone (n = 274), sustained-release oral morphine (n = 2), and oxycodone (n = 9). The adjusted odds of 60-day adherence to novel opioid alternatives were significantly higher for those receiving a mental health medication (aOR = 3.49, 95%CI = 1.26, 11.00), a higher maximum daily dosage of RMG prescriptions (aOR = 1.03 per mg increase, 95%CI = 1.01, 1.04), and those with continuous receipt of OAT (aOR = 6.25, 95%CI = 2.67, 15.90).

CONCLUSIONS

Higher dosages and co-prescription of mental health medications and OAT may help support better adherence to this form of prescriber-based "safer supply". Further work is needed to identify optimal prescribing practices and the longer term impacts of differing implementation scenarios.

The Prevalence and Psychosocial Correlates of Ketum (Mitragyna speciosa) Use among Individuals on Methadone Maintenance Therapy Programme in Hospital Taiping, Malaysia

Ketum use is significantly prevalent amongst individuals in the northern states of Peninsular Malaysia. This study aims to investigate the prevalence and psychosocial correlates of Ketum use in individuals who are in the Methadone Maintenance Therapy (MMT) Programme at the Hospital Taiping. This is a cross-sectional study conducted in the methadone clinic at the Hospital Taiping. The study instruments used were Subjective Opiate Withdrawal Scale (SOWS), Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) questionnaire, and Kratom Dependence Scale (KDS). A total of 215 subjects were recruited for this study. The prevalence of ketum users was 49.3% (n = 106). Chinese and Indian ethnicity had a lower tendency to use ketum compared to Malay ethnicity, with OR = 0.386 (95% CI 0.134, 1.113) and 0.119 (95% CI 0.035, 0.408), respectively. Individuals who used other illicit drugs had a higher tendency to use ketum with the adjusted OR = 9.914 (95% CI: 1.109, 88.602). Every one unit increase in SOWS increased the odds of being a ketum user by 1.340 (95% CI: 1.070, 1.677), whereas every one unit increase in duration in the MMT programme reduced the odds of being a ketum user by 0.990 (95% CI: 0.982, 0.998). Ketum use is prevalent amongst those in the MMT programme in this study. The high prevalence of ketum use is of concern and further interventions should be carried out to address this.

Trauma and post-traumatic stress disorder in patients treated for opioid use disorder: findings from a 12-month cohort study

BACKGROUND

Exposure to traumatic events is both a risk factor for substance use and an adverse outcome of substance use disorders. Identifying and managing post-traumatic stress disorder (PTSD) in patients with addiction requires attention.

AIMS

To examine the lifetime prevalence of traumatic events and past-month prevalence of PSTD in patients treated for opioid use disorder, and explore the association between trauma, PTSD and treatment outcomes.

METHOD

Participants (n = 674) receiving methadone treatment in 20 community clinics across Ontario, Canada, were administered the Mini-International Neuropsychiatric Interview to identify self-reported traumatic events and PTSD. Drug use was measured for 12 months by urine drug screens.

RESULTS

Eleven per cent of participants met past-month criteria for PTSD (n = 72), and 48% reported history of traumatic events with no current PTSD (n = 323). Participants with PTSD were more likely to be female (odds ratio 2.13, 95% CI 1.20-3.76) and less likely to be employed (odds ratio 0.31, 95% CI 0.16-0.61) or married (odds ratio 0.51, 95% CI 0.26-0.90) than those with no trauma history. Antidepressants (39 v. 24%) and benzodiazepines (36 v. 18%) were differentially prescribed to patients with and without PTSD. Length of time in treatment and opioid use were not associated with trauma; however, suicidal ideation was more common in PTSD (odds ratio 2.29, 95% CI 1.04-5.01).

CONCLUSIONS

Trauma and PTSD are prevalent among patients with opioid use disorder, and consideration of trauma symptoms and associated characteristics is warranted. Patients with and without comorbid PTSD differ clinically and psychosocially, highlighting the relevance of integrating addiction and mental health services for this population.

Association study of genetic polymorphisms in GABRD with treatment response and dose in methadone maintenance treatment

Aim: This study determined if gene variants in the GABA receptor delta subunit (GABRD) are associated with treatment response and dose in methadone maintenance treatment (MMT) for heroin addiction. Materials & methods: A total of 286 MMT patients were recruited and divided into response and nonresponse groups based on retention time in therapy. A total of 177 responders were classified into low dose and high dose subgroups according to the stabilized methadone dose. Four (single nucleotide polymorphisms) SNPs (rs13303344, rs4481796, rs2376805 and rs2229110) in GABRD were genotyped using the TaqMan SNP assay. Logistic regression was used to assess the genetic effects of the SNPs in MMT. Results: No significant associations were observed between the SNPs and treatment response or dose, except the frequency of haplotype ACGC at the four SNPs significantly differed between responders and nonresponders. Conclusion: The results indicated that GABRD variants may play a small role in modulating methadone treatment response.

Hepatitis C Virus Incidence in a Cohort in Medication-Assisted Treatment for Opioid Use Disorder in New York City

BACKGROUND

Hepatitis C virus (HCV) incidence has increased in the worsening opioid epidemic. We examined the HCV preventive efficacy of medication-assisted treatment (MAT), and geographic variation in HCV community viral load (CVL) and its association with HCV incidence.

METHODS

HCV incidence was directly measured in an open cohort of patients in a MAT program in New York City between 1 January 2013 and 31 December 2016. Area-level HCV CVL was calculated. Associations of individual-level factors, and of HCV CVL, with HCV incidence were examined in separate analyses.

RESULTS

Among 8352 patients, HCV prevalence was 48.7%. Among 2535 patients seronegative at first antibody test, HCV incidence was 2.25/100 person-years of observation (PYO). Incidence was 6.70/100 PYO among those reporting main drug use by injection. Female gender, drug injection, and lower MAT retention were significantly associated with higher incidence rate ratios. Female gender, drug injection, and methadone doses <60 mg were independently associated with shorter time to HCV seroconversion. HCV CVLs varied significantly by geographic area.

CONCLUSIONS

HCV incidence was higher among those with lower MAT retention and was lower among those receiving higher methadone doses, suggesting the need to ensure high MAT retention, adequate doses, and increased HCV prevention and treatment engagement. HCV CVLs vary geographically and merit further study as predictors of HCV incidence.

Craving and implicit attitude toward heroin use and their relationships with the levels of heroin dependence and methadone adherence in heroin users

Craving is a core feature of heroin use disorder. Craving for heroin is a conscious cognitive process. Recently, implicit (i.e., an implicit attitude toward heroin use) cognitive processes have been thought to be precursors of cravings. This study aimed to explore the associations of craving and implicit attitude toward heroin use with the level of heroin use disorder and adherence to methadone maintenance treatment (MMT). This study recruited 213 intravenous heroin users (196 males and 17 females) from MMT clinics of two hospitals. The mean age of participants was 42.3 years. They provided details of their severity of heroin use disorder and craving for heroin via questionnaires and also completed a computerized test to assess implicit attitude toward heroin use. The relationships between implicit attitude, craving, age, heroin use disorder, and MMT adherence were examined using path analysis. Craving was positively related to heroin use disorder (beta = 0.4). Implicit attitude directly and indirectly positively contributed to heroin use disorder (betas: 0.1 and 0.3). Craving was positively related to MMT adherence (beta: 0.2), whereas implicit attitude had an indirect effect on MMT adherence (beta: 0.03). Age was negatively associated with craving but was not associated with implicit attitude toward heroin. Methadone dosage was negatively associated with craving. Craving is significantly associated with the levels of heroin use disorder and MMT adherence. Meanwhile, craving mediates the relationship between implicit attitude and heroin use disorder, as well as MMT adherence. Implicit attitude also contributes to the level of heroin use disorder directly. For reducing craving, adequate dosage may be necessary.

The real-world impact of dosing of methadone and buprenorphine in retention on opioid agonist therapies in Ukraine

BACKGROUND AND AIMS

Ukraine's HIV epidemic remains concentrated among opioid-dependent people who inject drugs (PWID) where opioid agonist therapies (OAT) like methadone (MMT) and buprenorphine (BMT) maintenance treatments are the most cost-effective HIV prevention strategies, but remain under-scaled. This study aimed to measure the association between dose and type of OAT prescribed and treatment retention.

DESIGN

Observational longitudinal cohort study.

PARTICIPANTS AND SETTING

Patients (n = 15 290) prescribed OAT throughout Ukraine from 2004 through 2016.

MEASUREMENTS

Data were analyzed using time-event strategies to estimate cumulative treatment retention, defined as time to OAT discontinuation. Cumulative retention proportions at 1, 12 and 36 months were assessed for outcomes. Cox regression with log-rank likelihood assessed independent predictors of treatment discontinuation.

FINDINGS

The proportion prescribed high (MMT: > 85 mg; BMT: ≥ 16 mg), medium (MMT: > 40-85 mg; BMT: > 6-15 mg) and low (MMT: ≤ 40 mg; BMT: ≤ 6 mg) dosages was 25, 43 and 32%, respectively. Retention was significantly higher for BMT than MMT both at 12 (89 versus 75%) and 36 months (80 versus 56%). Although dosing levels for BMT did not influence retention, increasing dosages for MMT were significantly associated with higher retention rates at 1 (90, 96, 99%), 12 (59, 78, 91%) and 36 (34, 59, 79%) months, respectively. Independent predictors associated with 12-month OAT discontinuation were medium [adjusted hazard ratio (aHR) = 2.23; 95% confidence limit (CL) = 1.95-2.54] and low (aHR = 4.96; 95% CL = 4.37-5.63) OAT dosage relative to high dosage, male sex (aHR = 1.27; 95% CL = 1.14-1.41), MMT relative to BMT prescription (aHR = 1.57; 95% CL = 1.32-1.87) and receiving OAT in general (aHR = 1.22; 95% CL = 1.02-1.46) or tuberculosis (aHR = 1.43; 95% CL = 1.10-1.85) hospitals, relative to specialty addiction treatment and AIDS center settings. Lower dosages contributed more to dropout especially at 1 month (aHR 3.12; 95% CL = 2.21-4.41 and aHR 7.71; 95% CL = 5.51-10.79 for medium and low dosages, respectively). Younger age was significantly associated with OAT discontinuation only at 36 months (aHR = 1.08; 95% CI = 1.02-1.15).

CONCLUSIONS

Higher dosages of opioid agonist therapies, especially for methadone maintenance treatment patients, appear to be associated with higher levels of treatment retention in Ukraine.

A mixed methods study exploring methadone treatment disclosure and perceptions of reproductive health care among women ages 18-44 years, Los Angeles, CA

INTRODUCTION

Opioid use disorder (OUD) and methadone treatment are increasing among women ages 18-44 years old, a population with unique healthcare needs. Despite this increase, there is little research on the healthcare experiences of women with OUD, particularly experiences with reproductive healthcare.

METHODS

We designed a sequential, mixed-methods study in three Los Angeles methadone clinics. In the first phase, we conducted in-depth interviews with women in methadone treatment (n = 22) (September-December 2016). After thematic coding and analysis, we designed and administered a survey to understand patterns in women's experiences and reproductive health knowledge, attitudes, and behavior (n = 50) (January-April 2018). We conducted descriptive statistics, then integrated the quantitative and qualitative findings to contextualize and understand perceptions and experiences with healthcare providers among women in methadone treatment.

RESULTS

We found that women experienced and anticipated that providers would treat them poorly when they disclosed that they were in methadone treatment for OUD. Women's actual experiences with disclosure, shared in in-depth interviews, varied by whether they had disclosed their status intentionally or inadvertently. Approximately one-third (37%) of survey respondents thought a healthcare provider would scold them if they became pregnant; however, all who had been pregnant in the past while on methadone (n = 11) reported disclosing methadone treatment during pregnancy to their provider. Under a quarter of all women (22%) said having a healthy pregnancy while on methadone was likely or very likely. These perceptions were reinforced by negative experiences with providers, or, in many cases, women in the survey reported that they had never discussed the recommendations for a healthy pregnancy while on methadone with a healthcare provider.

DISCUSSION

Women experience and anticipate experiencing negative interactions with their healthcare providers if and when they disclose their methadone treatment. These perceptions and experiences impact subsequent treatment seeking and disclosure. The majority of women did not discuss pregnancy with healthcare providers. To improve quality of care, healthcare providers can provide a safe space for women to disclose methadone treatment through nonjudgmental communication that intentionally alleviates stigma. Additionally, healthcare providers should understand medical guidelines and laws/policies around methadone during pregnancy and communicate this understanding to all patients who may wish to become pregnant or who are at risk for unintended pregnancy.

Adverse Events During Treatment Induction With Injectable Diacetylmorphine and Hydromorphone for Opioid Use Disorder

OBJECTIVES

The present study aims to describe a 3-day induction protocol for injectable hydromorphone (HDM) and diacetylmorphine (DAM) used in 3 Canadian studies and examine rates of opioid-related overdose and somnolence during this induction phase.

METHODS

The induction protocol and associated data on opioid-related overdose and somnolence are derived from 2 clinical trials and one cohort study conducted in Vancouver and Montreal (2005-2008; 2011-2014; 2014-2018). In this analysis, using the Medical Dictionary for Regulatory Activities coding system we report somnolence (ie, drowsiness, sleepiness, grogginess) and opioid overdose as adverse events. Overdoses requiring intervention with naloxone are coded as severe adverse events.

RESULTS

Data from the 3 studies provides a total of 1175 induction injections days, with 700 induction injection days for DAM, and 475 induction injection days for HDM. There were 34 related somnolence and adverse event (AE) overdoses (4.899 per 100 injection days) in DAM and 6 (1.467 per 100 days) in HDM. Four opioid overdoses requiring naloxone (0.571 per 100 injection days) were registered in DAM and 1 in HDM (0.211 per 100 injection days), all safely mitigated onsite. The first week maximum daily dose patients received were on average 433.62 mg [standard deviation (SD) = 137.92] and 223.26 mg (SD = 68.06) for DAM and HDM, respectively.

CONCLUSIONS

A 3-day induction protocol allowed patients to safely reach high doses of injectable hydromorphone and diacetylmorphine in a timely manner. These findings suggest that safety is not an evidence-based barrier to the implementation of treatment with injectable hydromorphone and diacetylmorphine.

Open-label dose-extending placebos for opioid use disorder: a protocol for a randomised controlled clinical trial with methadone treatment

INTRODUCTION

More than 2 million individuals in the USA have an opioid use disorder (OUD). Methadone maintenance treatment is the gold standard of medication-based treatment for OUD, but high-dose methadone is associated with cardiotoxicity and respiratory complications, among other side effects. These adverse effects make enhancing the effectiveness of lower doses of methadone an attractive therapeutic goal. Long recognised for its capacity to enhance treatment outcomes for a wide range of neuropsychiatric disorders including pain, the placebo effect offers an as-yet untested avenue to such an enhancement. This approach is particularly compelling given that individuals with substance use disorder tend to have higher salience attribution and may thereby be more sensitive to placebo effects. Our study combines two promising clinical methodologies-conditioning/dose-extension and open-label placebo-to investigate whether placebo effects can increase the effective potency of methadone in treatment-seeking OUD patients.

METHODS AND ANALYSIS

A total of 120 newly enrolled treatment-seeking OUD patients will be randomly assigned to one of two different groups: either methadone plus daily placebo dose-extension (PDE; treatment group) or methadone/treatment as usual (control). Participants will meet with study team members five times over the course of 3 months of treatment with methadone (baseline, 2 weeks, and 1, 2 and 3 months postbaseline). Throughout this study time period, methadone dosages will be adjusted by an addiction clinician blind to patient assignment, per standard clinical methods. The primary outcome is methadone dose at 3 months. Secondary outcomes include self-report of drug use; 3-month urine toxicology screen results; and treatment retention. Exploratory outcomes include several environmental as well as personality factors associated with OUD and with propensity to demonstrate a placebo effect.

ETHICS AND DISSEMINATION

Human subjects oversight for this study is provided by the University of Maryland, Baltimore and University of Maryland, College Park Institutional Review Boards. Additionally, the study protocol is reviewed annually by an independent Data and Safety Monitoring Board. Study results will be disseminated via research conference presentations and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT02941809.

Sexual Functioning and Opioid Maintenance Treatment in Women. Results From a Large Multicentre Study

Opioid maintenance treatment (OMT) is the most widespread therapy for both females and males opioid addicts. While many studies have evaluated the OMT impact on men's sexuality, the data collected about the change in women's sexual functioning is still limited despite the fact that it is now well-known that opioids - both endogenous and exogenous - affect the endocrine system and play an important role in sexual functioning. The present study aims to determine how OMT with buprenorphine (BUP) or methadone (MTD) affects sexual health in women; examining also any possible emerging correlation between sexual dysfunction (SD), type of opioid and patients' mental health. This multi-center study case recruited 258 female volunteers attending Italian public Addiction Outpatients Centers that were stabilized with OMT for at least 3 months. SD was assessed with the Arizona Sexual Experience Scale. The twelve-item General Health Questionnaire was used to assess participants' mental health conditions. The results show that 56.6% of women receiving OMT for at least 3 months presented SD without significant differences between MTD e BUP groups. The majority of the subjects with SD have a poorer quality of intimate relationships and worse mental health than the average. To the best of our knowledge, the present study is the largest report on the presence of SDs in women as a side effects of MTD and BUP used in OMT. Since SDs cause difficulties in intimate relationships, lower patients' quality of life and interfere with OMT beneficial outcomes, we recommend that women undertaking an opioid therapy have routine screening for SD and we highlight the importance to better examine opioid-endocrine interactions in future studies in order to provide alternative potential treatments such as the choice of opioid, opioid dose reduction and hormone supplementation.

Testing a Neuro-Evolutionary Theory of Social Bonds and Addiction: Methadone Associated With Lower Attachment Anxiety, Comfort With Closeness, and Proximity Maintenance

Evidence from non-human mammals for the involvement of the endogenous opioid system in prosocial behavior is reasonably extensive and robust; however, studies in humans are lacking. This study tests the neuro-evolutionary hypothesis that exogenous opiates, including morphine, heroine, and methadone, decrease separation anxiety and proximity by hijacking the neuro-peptide endogenous opioid system modulating social bonds. Participants were 486 subjects, 43% male, with ages between 18 and 62 years (M = 26.4; SD = 9.4), divided in three naturalistic groups: 1: addicts in drug-free treatment; 2: addicts in methadone programs; 3: normative non-clinical controls. Instruments: 1) Adult Attachment Scale (AAS) composed of three subscales: Anxiety about being rejected (α = 0.83), Comfort with Intimacy (α = 0.68), and Comfort Depending on Others (α = 0.70). 2) Caregiving Questionnaire composed of four subscales: Proximity Maintenance: (α = 0.83), Sensitivity: (α = 0.76), Controlling Caregiving (α = 0.77) and Compulsive Caregiving (α = 0.68). Results: Multivariate Analysis of Co-variance (MANCOVA) models were computed; gender, age, and education were included in the models. Methadone patients and drug-free treatment addicts were equivalent and reported significantly lower Comfort Depending on Others, Comfort with Intimacy, and Caregiving Proximity. However, methadone users reported significantly lower Anxiety about being rejected than drug-free addicts and were equivalent to non-clinical controls. In addition, correlations between the methadone intake dose and the questionnaires' scales showed that dose was significantly and negatively correlated with Comfort with Closeness (rs = -0.36; p < 0.01) and with Caregiving Proximity (rs = -0.28; p < 0.05).

A cluster-analytic profiling of heroin-dependent patients based on level, clinical adequacy, and patient-desired adjustment of buprenorphine dosage during buprenorphine-naloxone maintenance treatment in sixteen Spanish centers

BACKGROUND

Buprenorphine dosage is a crucial factor influencing outcomes of buprenorphine treatment for heroin use disorders. Therefore, the aim of the present study is to identify naturally occurring profiles of heroin-dependent patients regarding individualized management of buprenorphine dosage in clinical practice of buprenorphine-naloxone maintenance treatment.

METHODS

316 patients receiving buprenorphine-naloxone maintenance treatment were surveyed at 16 Spanish centers during the stabilization phase of this treatment. Patients were grouped using cluster analysis based on three key indicators of buprenorphine dosage management: dose, adequacy according to physician, and adjustment according to patient. The clusters obtained were compared regarding different facets of patient clinical condition.

RESULTS

Four clusters were identified and labeled as follows (buprenorphine average dose and percentage of participants in each cluster are given in brackets): "Clinically Adequate and Adjusted to Patient Desired Low Dosage" (2.60 mg/d, 37.05%); "Clinically Adequate and Adjusted to Patient Desired High Dosage" (10.71 mg/d, 29.18%); "Clinically Adequate and Patient Desired Reduction of Low Dosage" (3.38 mg/d, 20.0%); and "Clinically Inadequate and Adjusted to Patient Desired Moderate Dosage" (7.55 mg/d, 13.77%). Compared to patients from the other three clusters, participants in the latter cluster reported more frequent use of heroin and cocaine during last week, lower satisfaction with buprenorphine-naloxone as a medication, higher prevalence of buprenorphine-naloxone adverse effects and poorer psychological adjustment.

CONCLUSIONS

Our results show notable differences between clusters of heroin-dependent patients regarding buprenorphine dosage management. We also identified a group of patients receiving clinically inadequate buprenorphine dosage, which was related to poorer clinical condition.

Evidence of validity and reliability of the Opiate Dosage Adequacy Scale (ODAS) in a sample of heroin addicted patients in buprenorphine/naloxone maintenance treatment

OBJECTIVE

The Opiate Dosage Adequacy Scale (ODAS) is a clinical tool to individually measure the "adequacy" of opioid doses in patients on maintenance treatment. The aim of this paper is to provide evidence for the validity and reliability of the ODAS in a sample of patients in buprenorphine/naloxone (B/N) maintenance treatment.

METHOD

Cross-sectional study of a convenience sample of B/N-treated patients (n = 316) from four Autonomous Communities in Spain. Participants completed a battery of instruments to assess the following: buprenorphine dose adequacy; heroin dependence severity; psychological adjustment; and patient-desired adjustment of buprenorphine dose.

RESULTS

Exploratory Factor Analysis identified four factors from the ODAS that together account for 85.4% of the total variance: "Heroin craving and use"; "Overmedication"; "Objective opiate withdrawal symptoms (OWS)" and 'Subjective OWS'. Compared to patients with an "inadequate" B/N dose (ODAS), patients with "adequate" doses had less heroin use in the last week (0.01 vs. 0.40; t = -2.73; p < 0.01, 95% CI: -0.67, -0.10), less severe heroin dependence (2.20 vs. 5.26, t = -5.14, p < 0.001; 95% CI: -4.23, -1.88), less psychological distress (3.00 vs. 6.31, t = -4.37, p < 0.001; 95% CI: -4.80, -1.81), and greater satisfaction with their doses (42.1% vs. 13.6%, χ² = 14.44, p < 0.01). Cronbach's alpha coefficient was 0.76 (0.81, 0.92, 0.94, and 0.93, respectively, for the four factor dimensions).

CONCLUSION

These findings support the validity and reliability of the ODAS as a tool to measure and assess buprenorphine dose adequacy in the context of an opioid dependency treatment program.

Methadone Dose Adjustments, Plasma R-Methadone Levels and Therapeutic Outcome of Heroin Users: A Randomized Clinical Trial

AIMS

We aimed to improve the retention in treatment and therapeutic outcome of methadone maintenance treatment (MMT) patients by adjusting the oral methadone dose in order to reach a "target" plasma R-methadone level (80-250 ng/mL).

METHODS

A multicenter randomized controlled trial was organized.

RESULTS

The intention-to-treat statistical analysis showed that repeated dose adjustments performed in order to obtain therapeutic plasma R-methadone levels did not improve retention in treatment of heroin-dependent patients. However, patients having plasma methadone levels in the "target range" at the beginning of the study had a better retention in treatment than controls. Furthermore, patients succeeding in keeping plasma R-methadone target levels (per protocol analysis) remained in treatment and improved their social scores better than controls. -Conclusion: Although the primary endpoint of this study was not demonstrated, a post hoc and a per protocol analysis suggested that patients in MMT with plasma R-methadone concentrations in the target range have a better therapeutic outcome than controls.

Sex Differences in Regional Brain Glucose Metabolism Following Opioid Withdrawal and Replacement

Methadone and buprenorphine are currently the most common pharmacological treatments for opioid dependence. Interestingly, the clinical response to these drugs appears to be sex specific. That is, females exhibit superior therapeutic efficacy, defined as extended periods of abstinence and longer time to relapse, compared with males. However, the underlying metabolic effects of opioid withdrawal and replacement have not been examined. Therefore, using ¹⁸FDG and microPET, we measured differences in regional brain glucose metabolism in males and females following morphine withdrawal and subsequent methadone or buprenorphine replacement. In both males and females, spontaneous opioid withdrawal altered glucose metabolism in regions associated with reward and drug dependence. Specifically, metabolic increases in the thalamus, as well as metabolic decreases in insular cortex and the periaqueductal gray, were noted. However, compared with males, females exhibited increased metabolism in the preoptic area, primary motor cortex, and the amygdala, and decreased metabolism in the caudate/putamen and medial geniculate nucleus. Methadone and buprenorphine initially abolished these changes uniformly, but subsequently produced their own regional metabolic alterations that varied by treatment and sex. Compared with sex-matched control animals undergoing spontaneous opioid withdrawal, male animals treated with methadone exhibited increased caudate/putamen metabolism, whereas buprenorphine produced increased ventral striatum and motor cortex metabolism in females, and increased ventral striatum and somatosensory cortex metabolism in males. Notably, when treatment effects were compared between sexes, methadone-treated females showed increased cingulate cortex metabolism, whereas buprenorphine-treated females showed decreased metabolism in cingulate cortex and increased metabolism in the globus pallidus. Perhaps the initial similarities in males and females underlie early therapeutic efficacy, whereas these posttreatment sex differences contribute to clinical treatment failure more commonly experienced by the former.

Patient perception of methadone dose adequacy in methadone maintenance treatment: The role of perceived participation in dosage decisions

OBJECTIVE

In clinical practice, methadone maintenance treatment (MMT) entails tailoring the methadone dose to the patient's specific needs, thereby individualizing treatment. The aim of this study was to identify the independent factors that may significantly explain methadone dose adequacy from the patient's perspective.

METHOD

Secondary analysis of data collected in a treatment satisfaction survey carried out among a representative sample of MMT patients (n=122) from the region of La Rioja (Spain). As part of the original study protocol, participants completed a comprehensive battery to assess satisfaction with MMT, psychological distress, opinion of methadone as a medication, participation in dosage decisions, and perception of dose adequacy.

RESULTS

Multivariate binary logistic regression showed that the only variable independently associated with the likelihood of a patient perceiving methadone dose as inadequate was the variable perceived-participation in methadone dosage decisions (OR=0.538, 95% CI=0.349-0.828).

CONCLUSION

Patient participation in methadone dosage decisions was predictive of perceived adequacy of methadone dose beyond the contribution of other socio-demographic, clinical, and MMT variables.

PRACTICE IMPLICATIONS

Patient participation in methadone dosage decision-making is valuable for developing a genuinely patient-centred MMT.

The newer Opioid Agonist Treatment with lower substitutive opiate doses is associated with better toxicology outcome than the older Harm Reduction Treatment

BACKGROUND

Charge-free heroin use disorder treatment in Italy follows two main approaches, i.e., harm reduction treatment (HRT) strategy in community low-threshold facilities for drug addiction and opioid agonist treatment (OAT) in high-threshold facilities for opioid addiction, focusing on pharmacological maintenance according to the Dole and Nyswander strategy. We aimed to compare the impact of HRT and OAT on patient outcome, as assessed through negativity for drugs on about 1-year urinalyses.

METHODS

We examined retrospectively the urinalyses of HRT and OAT patients for which at least four randomly sampled urinalyses per month were available for about 1 year, during which patients were undergoing methadone or buprenorphine maintenance; urinalyses focused on heroin, cocaine, cannabinoids, and their metabolites.

RESULTS

Included were 189 HRT and 58 OAT patients. The latter were observed for a significantly longer period. There was a higher proportion of heroin- and cocaine-clean urinalyses in OAT patients, with cocaine-clean urinalyses discriminating best between the two groups. OAT patients were older, with longer dependence duration, more severe addiction history, and received lower methadone doses. Buprenorphine maintenance was more often associated with heroin-clean urinalyses. The higher the methadone doses, the lower were the percentage of heroin-clean urinalyses in HRT patients (negative correlation).

CONCLUSIONS

The OAT approach was related to higher recovery and polyabuse abstinence rates compared to the HRT approach, despite greater severity of substance use, psychiatric and physical comorbidities. Our results are consistent with the possibility to use lower maintenance opiate doses (after induction and stabilization in methadone treatment according to Dole and Nyswander methodology) in treating heroin addiction. This seemed to be impossible adopting the currently accepted HRT model.

A placebo-controlled trial of dextromethorphan as an adjunct in opioid-dependent patients undergoing methadone maintenance treatment

BACKGROUND

Low-dose dextromethorphan (DM) might have anti-inflammatory and neurotrophic effects mechanistically remote from an NMDA receptor. In a randomized, double-blind, controlled 12 week study, we investigated whether add-on dextromethorphan reduced cytokine levels and benefitted opioid-dependent patients undergoing methadone maintenance therapy (MMT).

METHODS

Patients were randomly assigned to a group: DM60 (60mg/day dextromethorphan; n = 65), DM120 (120mg/day dextromethorphan; n = 65), or placebo (n = 66). Primary outcomes were the methadone dose required, plasma morphine level, and retention in treatment. Plasma tumor necrosis factor (TNF)-α, C-reactive protein, interleukin (IL)-6, IL-8, transforming growth factor-β1, and brain-derived neurotrophic factor (BDNF) levels were examined during weeks 0, 1, 4, 8, and 12. Multiple linear regressions with generalized estimating equation methods were used to examine the therapeutic effect.

RESULTS

After 12 weeks, the DM60 group had significantly longer treatment retention and lower plasma morphine levels than did the placebo group. Plasma TNF-α was significantly decreased in the DM60 group compared to the placebo group. However, changes in plasma cytokine levels, BDNF levels, and the methadone dose required in the three groups were not significantly different.

CONCLUSIONS

We provide evidence-decreased concomitant heroin use-of low-dose add-on DM's efficacy for treating opioid-dependent patients undergoing MMT.

Assessment of CYP450 genetic variability effect on methadone dose and tolerance

Aim: Methadone dose is related to treatment success in individuals under methadone maintenance treatment (MMT). We constructed a gene matrix using previously identified genetic polymorphisms in CYP450 and determined their genetic influence on methadone dose or tolerance. Materials & methods: The allelic combinations of CYP450 genetic variants (two from CYP2C19, four from CYP2B6 and five from CYP3A4) were analyzed in 366 MMT heroin dependent patients as possible determinants of methadone dose and tolerance using analysis of covariance. Results: Methadone dose (p = 0.007) and tolerance (p = 0.06) were mainly influenced by CYP2C19 gene dose. Moreover, dominant influence of the CYP2C19 gene dose on methadone dose and tolerance was only found among MMT patients with negative urine morphine test results, but not among those with positive results. Conclusion: The findings suggest that CYP2C19 gene dose may serve as a potential indicator for assessing methadone dose and tolerance in MMT patients.

Original submitted 5 September 2013; Revision submitted 23 January 2014

Meaning and methadone: patient perceptions of methadone dose and a model to promote adherence to maintenance treatment

OBJECTIVES

Methadone maintenance treatment (MMT) effectively reduces illicit opioid use and its negative consequences when patients participate in and adhere to treatment. Patients' participation and adherence may relate to their perceptions about methadone doses and dose adjustments and the meanings that patients associate with treatment. This study assessed patient perceptions about methadone dosing and the meanings associated with methadone treatment to better support patient adherence to and success in MMT.

METHODS

We conducted semistructured interviews with 19 patients in an urban MMT program. Interviews were transcribed verbatim and analyzed through an iterative process.

RESULTS

Participants' expressed perceptions about methadone doses related to ideas of "comfort" and "function," suggesting a model for determining dose appropriateness and "ideal" methadone dose based on various factors both intrinsic and extrinsic to MMT. Intrinsic factors included those exerting downward pressure on "ideal" methadone dose such as lack of control in treatment, disdain for getting "high," concerns about methadone dependence, and desire to avoid adverse effects; those exerting upward pressure such as concern about withdrawal; and those exerting mixed pressures such as methadone formulations. Extrinsic factors included those exerting downward pressure such as shame about and stigma around MMT; those exerting upward pressure such as medical conditions and medication interactions; and those exerting mixed pressures such as family and peer relationships.

CONCLUSIONS

Participants held perceptions about methadone dosing that included considerations beyond typical medical parameters used by physicians and other MMT providers to determine appropriate methadone doses. The model that emerged from our data could help inform MMT providers to support greater patient comfort with methadone doses and dose changes, as well as adherence to and success in MMT.

A qualitative study exploring the reason for low dosage of methadone prescribed in the MMT clinics in China

OBJECTIVES

Dosage of methadone maintenance therapy (MMT) is an important factor influencing retention in methadone treatment. MMT clients in China received lower dosages of methadone compared with those provided in other countries. The objective of this study is to elucidate the reason for the low methadone dosage prescribed in MMT clinics in China.

METHODS

Twenty-eight service providers were recruited from the MMT clinics in Zhejiang and Jiangxi Provinces, China. Qualitative in-depth interviews were conducted to ascertain the procedure for prescribing methadone in the MMT clinics.

RESULTS

The average dosage prescribed in the 28 clinics was 35 mg/person/day. Four major themes resulting in low dosage of methadone were identified: (1) the service providers fear the liability resulting from large doses of methadone in combination with other substances which might result in overdose fatalities, (2) lack of understanding of harm reduction which resulted in low acceptance of the long term maintenance treatment approach, (3) break-down in communication between clients and service providers about dosage adjustment, and (4) dosage reduction is perceived by most service providers as an effective way to treat the side-effects associated with MMT.

CONCLUSIONS

The findings of the study highlighted the necessity to formulate clear guidelines concerning individualized dosage management and to improve training among service providers' in MMT clinics in China.

Methadone maintenance dosing guideline for opioid dependence, a literature review

To date, methadone dosing is still an issue of debate and controversy among clinicians who are involved in methadone maintenance programs. The authors conducted a literature review to update clinicians about this issue and provide recommendations for proper methadone dosing. Studies eligible for inclusion in the review were retrieved from the PubMed database by searching for reports published between 1990 and September 2008 using the major medical subject headings Methadone (all fields) and dose. Only articles written in English were included. Additional reports were identified from the reference lists of retrieved articles and by manual review of the tables of contents of journals on drug of abuse included in the psychiatry and substance abuse subject category listing 2008 of the Journal Citation Reports. Abstracts of medical meetings were excluded. Twenty-four articles were included in the review. Twelve are randomized, controlled, or double-blind clinical trials, 10 are non-randomized and observational studies, and 2 are meta-analyses. Currently, the consensus is to have a goal for methadone dosing in the range of 60 to 100 mg daily. For patients who continue to use illicit opiates while prescribed this dose range, clinicians may consider doses greater than 100 mg daily. However, this is not the current consensus but rather is based on the limited promising data the authors have; it could be considered if the benefits outweigh the risks for some patients.

Effects of a single 50% extra dose of methadone on heroin craving and mood in lower- versus higher-dose methadone patients

Some patients on steady-state methadone occasionally crave for extra opioids for different reasons (eg, cue-elicited craving, stress). This study examined the acute-on-chronic effects on heroin craving, mood, and opioid-like symptoms of a single, extra half-dose on top of the patient's prescribed daily methadone dosage. A randomized, double-blind, placebo-controlled, counterbalanced crossover design was used to test the safety of this practice and the hypotheses that extra methadone would reduce heroin craving and improve mood, with greater responses in lower-dose (20-60 mg/d) as compared with higher-dose patients (80-120 mg/d). Fourteen stabilized methadone-maintained volunteers of each dose group were examined predrug and postdrug on 2 separate days using a range of self-report measures (Heroin Craving Questionnaire, visual analogs, Befindlichkeits-Skala, Short Opiate Withdrawal Scale, and Opioid Agonist Scale). Additionally, patients' expectations and guesses regarding treatment were assessed predrug and postdrug, respectively. No adverse effects occurred after extra methadone. Participants could not reliably distinguish between extra methadone and placebo. Repeated-measures analyses of variance showed no effects of extra methadone on heroin craving and opioid agonist effects. However, extra methadone improved mood on the Befindlichkeits-Skala (F1/24 = 4.71, P = 0.04), with marginally greater effects in lower-dose patients ((F1/24 = 2.94, P = 0.099). A single 50% extra methadone dose is most likely safe in patients on stable methadone doses of 20 to 120 mg/d and may improve patients' mood. Extra methadone may constitute an important factor in the attractiveness of maintenance treatment and may enhance treatment outcome.

The cost of concordance with opiate substitution treatment guidelines

The Multisite Opiate Substitution Treatment study compared four opioid substitution programs that were highly concordant with clinical practice guidelines to four programs that were less concordant. Program staff were surveyed, and consenting new patients from highly concordant (n = 164) and less-concordant programs (n = 91) were assessed. After 12 months, treatment of new clients of highly staffed, guideline concordant sites cost $10,252, which is significantly more than the $6,476 cost at less-concordant programs (p < .01). Clients at highly concordant sites received significantly more group visits (M = 37.0 vs. 13.1, p < .01) but fewer dosing visits. There were no significant differences in medical care costs. Opioid substitution therapy was effective at reducing heroin use, especially at sites that were highly concordant with treatment guidelines. Annual mortality was 3.0% and did not differ by type of care. Preference-based quality of life significantly improved only at highly concordant sites.

Decreased reinforcing effects of cocaine following 2 weeks of continuous D-amphetamine treatment in rats

RATIONALE

Recent studies have investigated D-amphetamine as a potential agonist medication for cocaine dependence. In rats, a 14-day continuous infusion of D: -amphetamine via osmotic mini-pump has been shown to decrease cocaine-reinforced responding under a progressive ratio (PR) schedule of reinforcement.

OBJECTIVES

This study was designed to assess the influences of the D-amphetamine treatment dose and self-administered cocaine dose on the magnitude of this effect.

MATERIALS AND METHODS

Experiment 1: rats were trained to self-administer 1.5 mg/kg/inj cocaine under a PR schedule, then implanted with D-amphetamine mini-pumps for 14 days (days 1-7, 5 mg/kg/day; days 8-14, 7.5 mg/kg/day). Breakpoints were evaluated throughout the treatment period and 14 days post-treatment. Experiment 2: rats were trained to self-administer cocaine under a PR schedule and initial dose-response curves were determined before implantation of D-amphetamine mini-pumps. During the 14-day D-amphetamine (5 mg/kg/day) treatment period, rats self-administered one of four cocaine doses (0.19, 0.38, 0.75, or 1.5 mg/kg/inj). A post-treatment PR dose-response curve and responding under a fixed ratio 1 (FR1) schedule were evaluated after mini-pump removal.

RESULTS

Experiment 1: breakpoints for 1.5 mg/kg/inj cocaine were unchanged by the increasing dose of D-amphetamine. Experiment 2: the PR dose-response curve was shifted downward after the treatment period in rats that had self-administered 0.19 and 0.38 mg/kg/inj cocaine. In contrast, rats in the 0.75 and 1.5 mg/kg/inj groups demonstrated increased rates of cocaine intake under an FR1 schedule after the treatment period.

CONCLUSIONS

These data suggest that continuous D-amphetamine treatment attenuates the reinforcing effects of cocaine.

A meta-analysis of retention in methadone maintenance by dose and dosing strategy

OBJECTIVE

To estimate, via meta-analysis, the influence of different methadone dose ranges and dosing strategies on retention rates in methadone maintenance treatment (MMT).

METHODS

A systematic literature search identified 18 randomized controlled trials (RCTs) evaluating methadone dose and retention. Retention was defined as the percentage of patients remaining in treatment at a specified time point. After initial univariate analyses of retention by Pearson chi-squares, we used multilevel logistic regression to calculate summary odds ratios (ORs) and 95% confidence intervals for the effects of methadone dose (above or below 60 mg/day), flexible vs. fixed dosing strategy, and duration of follow-up.

RESULTS

The total number of opioid-dependent participants in the 18 studies was 2831, with 1797 in MMT and 1034 receiving alternative mediations or placebo. Each variable significantly predicted retention with the other variables controlled for. Retention was greater with methadone doses > or = 60 than with doses < 60 (OR: 1.74, 95% CI: 1.43-2.11). Similarly, retention was greater with flexible-dose strategies than with fixed-dose strategies (OR: 1.72, 95% CI: 1.41-2.11).

CONCLUSIONS

Higher doses of methadone and individualization of doses are each independently associated with better retention in MMT.

Personality factors associated with methadone maintenance dose

OBJECTIVES

Methadone is the most frequently prescribed medication for the treatment of opioid dependence in the U.S., and questions relating to appropriate dosing of methadone remain an important issue. Given accumulating evidence suggesting an elevated prevalence of personality pathology in opioid dependent populations, as well as evidence of an association between Cluster B characteristics and substance use severity, we hypothesized that patients with such pathology would have elevated methadone dose prescriptions.

METHODS

Participants were 54 opioid dependent individuals recruited from a methadone maintenance clinic.

RESULTS

RESULTS indicated that participants with symptoms consistent with Cluster B pathology had a significantly higher mean prescribed methadone dose relative to participants without Cluster B pathology.

CONCLUSION

The presence of personality traits appears to influence methadone maintenance. Implications of this finding are discussed.

Psychotherapeutic benefits of opioid agonist therapy

Opioids have been used for centuries to treat a variety of psychiatric conditions with much success. The so-called "opium cure" lost popularity in the early 1950s with the development of non-addictive tricyclic antidepressants and monoamine oxidase inhibitors. Nonetheless, recent literature supports the potent role of methadone, buprenorphine, tramadol, morphine, and other opioids as effective, durable, and rapid therapeutic agents for anxiety and depression. This article reviews the medical literature on the treatment of psychiatric disorders with opioids (notably, methadone and buprenorphine) in both the non-opioid-dependent population and in the opioid-dependent methadone maintenance population. The most recent neurotransmitter theories on the origin of depression and anxiety will be reviewed, including current information on the role of serotonin, N-Methyl d-Aspartate, glutamate, cortisol, catecholamine, and dopamine in psychiatric disorders. The observation that methadone maintenance patients with co-existing psychiatric morbidity (so called dual diagnosis patients) require substantially higher methadone dosages by between 20% and 50% will be explored and qualified. The role of methadone and other opioids as beneficial psychiatric medications that are independent of their drug abuse mitigating properties will be discussed. The mechanisms by which methadone and other opioids can favorably modulate the neurotransmitter systems controlling mood will also be discussed.

A randomized trial of 6-month methadone maintenance with standard or minimal counseling versus 21-day methadone detoxification

BACKGROUND

Important questions remain regarding the necessary duration and intensity for methadone treatment to be effective.

METHODS

As part of a clinical trial of tuberculosis chemoprophylaxis [Batki, S.L., Gruber, V.A., Bradley, J.M., Bradley, M., Delucchi, K., 2002. A controlled trial of methadone treatment combined with directly observed isoniazid for tuberculosis prevention in injection drug users. Drug Alcohol Depend. 66 283-293. doi:10.1016/S0376-8716(01)00208-3], patients with opioid dependence were recruited from an outpatient 21-day methadone detoxification program and were randomly assigned to one of three treatment conditions: (1) continuation in 21-day methadone detoxification; (2) transfer to 6-month methadone maintenance with only minimal counseling; or (3) transfer to 6-month methadone maintenance with standard twice monthly counseling and as-needed social work and psychiatric services. Both the 6-month maintenance treatments were followed by 1.5 months of detoxification. Urine drug tests and self-report measures were collected at baseline, months 1-6, and month 8.5.

RESULTS

Compared to 21-day methadone detoxification, 6-month methadone maintenance with either minimal or standard counseling resulted in fewer opiate positive urine tests and days of self-reported heroin and alcohol use. There was no change in cocaine use or other outcome measures. The increased counseling available in the standard counseling condition did not appear to reduce heroin use further than the minimal counseling condition, in contrast to the effect found for more structured counseling in long-term methadone maintenance (McLellan et al., 1993).

CONCLUSIONS

Six months of methadone maintenance, even with minimal counseling, reduces heroin and alcohol use more than 21-day methadone detoxification.

Informed consent to opioid agonist maintenance treatment: recommended ethical guidelines

BACKGROUND

Some bioethicists have questioned whether opioid addicted individuals are able to provide free and informed consent to opioid agonist maintenance treatment. Conflicting motives for providing such treatment (e.g. improving the personal health of addicts and protecting public health and order) can also influence what individuals are required to consent to, and how that consent is obtained. We discuss both issues and attempt to specify the conditions for obtaining informed consent to agonist maintenance treatment for opioid addiction.

METHODS

We briefly review the neuroscientific literature on the effects of addiction on the autonomy and decision-making capacity of opioid dependent individuals, and ascertain how informed consent to the treatment of opioid addiction should be obtained. We also provide an ethical analysis of the competing social and medical forces that influence the consent process and make some recommendations on how to ensure that individuals enter maintenance treatment that is provided in an effective and ethical way.

RESULTS

Our analysis shows that whilst the autonomy of opioid dependent individuals is impaired by their addiction, they do retain the ability to consent to treatment provided they are not in acute withdrawal or intoxication. These symptoms should have abated, either by supervised withdrawal or stabilisation on agonist maintenance, before they are asked to consent to a detailed treatment contract. Once stabilised, individuals should be provided with detailed information about the risks and benefits of all treatments, and restrictions and regulations under which they are provided.

CONCLUSION

Informed consent is an important part of the treatment process that should be obtained in ways that increase the autonomy and decision-making capacity in opioid addicts.

Endogenous opiates and behavior: 2006

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