Clinical Use of Methadone

Sick of Feeling Sick: Management of Opioid Treatment-Induced Refractory Nausea Resulting in Suicidal Ideations With a Plan and Intent

In this case report, we present the case of a 60-year-old Caucasian male with a history of depression, anxiety, opioid dependence, and idiopathic polyneuropathy, admitted to an inpatient psychiatric unit for suicidal ideation. The patient's symptoms were characterized by months of intractable nausea, severe anxiety, suicidal ideation (SI), and significant unintentional weight loss in the context of methadone-assisted treatment. Over nine days in the hospital, a treatment strategy was developed and refined, which eventually achieved sustained relief from nausea and significant improvement in anxiety. The most effective pharmacological interventions included mirtazapine, scopolamine, and gabapentin.

Prevalence and longitudinal correlates of recent exposure to fentanyl among HIV-positive people who use unregulated drugs during a community-wide overdose crisis

The United States and Canada are experiencing an opioid overdose crisis driven largely by exposure to fentanyl (a potent synthetic opioid), with little known about fentanyl exposure among HIV-positive people who use unregulated drugs (PWUD). We sought to estimate the prevalence and correlates of fentanyl exposure among a community-recruited sample derived from a prospective cohort study of HIV-positive PWUD in Vancouver, Canada. Generalized linear mixed-effects analyses were used to identify longitudinal factors associated with a fentanyl-positive urine drug screen test. Between June 2016-November 2017, 456 participants were recruited and contributed 1007 observations. At baseline, 96% of participants were ART-exposed, 72% had an HIV viral load (VL) <50 copies/mL and 21% had a fentanyl-positive test. Longitudinally, fentanyl-positive tests were characterized by: younger participant age (Adjusted Odds Ratio [AOR] = 0.45), recent non-fatal overdose (AOR = 2.30), engagement in opioid agonist therapy (AOR = 1.91), and at least daily heroin injection (AOR = 11.27). CD4+ cell count was negatively associated with fentanyl urine positivity (AOR = 0.92) (all p < 0.05). We identified several risk factors for overdose linked to fentanyl exposure among this sample, although no link with HIV treatment engagement or detectable HIV VL. Innovative strategies are needed to reduce the harmful effects of the contaminated unregulated drug supply experienced by PWUD.

Full Opioid Agonists and Tramadol: Pharmacological and Clinical Considerations

Opioids are mu receptor agonists and have been an important part of pain treatment for thousands of years. In order to use these drugs appropriately and successfully in patients, whether to control pain, to treat opiate-induced side effects, or opiate withdrawal syndromes, a solid understanding of the pharmacology of such drugs is crucial. The most recognized full agonist opioids are heroin, morphine, codeine, oxycodone, meperidine, and fentanyl. Phenanthrenes refer to a naturally occurring plant-based compound that includes three or more fused rings. The opioids derived from the opium plant are phenanthrene derivatives, whereas most synthetic opioids are simpler molecules that do not have multiple rings. Methadone acts as a synthetic opioid analgesic similar to morphine in both quality and quantity; however, methadone lasts longer and in oral form, has higher efficacy, and is considered a diphenylheptane. Fentanyl is a strong synthetic phenylpiperdine derivative that exhibits activity as a mu-selective opioid agonist approximately 50 to 100 times more potent than morphine. Meperidine is another medication which is a phenylpiperdine. Tramadol is considered a mixed-mechanism opioid drug, as it is a centrally acting analgesic that exerts its effects via binding mu receptors and blocking the reuptake of monoamines. Some of the most common adverse effects shared among all opioids are nausea, vomiting, pruritus, addiction, respiratory depression, constipation, sphincter of Oddi spasm, and miosis (except in the case of meperidine). Chronic opioid usage has also established a relationship to opioid-induced hypogonadism and adrenal suppression. Physicians must be stewards of opioid use and use opioids only when necessary.

Interaction between methadone and clarithromycin as the suspected cause of an opioid toxidrome

A 40-year-old patient was admitted through the acute medical take with pleuritic chest pain and rigours. He had a medical history of opiate dependence and was receiving 60 mg of methadone once daily. He was diagnosed with a community-acquired pneumonia and treated with amoxicillin and clarithromycin. After administration of only two concomitant doses of methadone and oral clarithromycin, he developed an opioid toxidrome with type-2 respiratory failure, a decreased level of consciousness and pinpoint pupils. The patient was treated with naloxone and his symptoms improved. Retrospectively, it was suspected that an interaction between clarithromycin and methadone might have contributed to the toxidrome. Respiratory failure has not been previously prescribed for this combination of medication and is of high importance for physicians and pharmacists around the world.

Patient perspectives of methadone formulation change in British Columbia, Canada: outcomes of a provincial survey

BACKGROUND

In British Columbia, Canada, methadone maintenance treatment formulation transitioned from the oral liquid compound Tang™-flavoured methadone to the ten-times more concentrated cherry-flavoured Methadose™ in February 2014. We quantitatively describe perceptions and reported consequences among a sample of patients on methadone maintenance treatment following this transition.

METHODS

A province-wide survey was used. Bivariable analyses utilized independent samples t-tests, Phi associations, and Chi-square tests. Multivariable logistic regression analyses evaluated factors related to dependent variables - namely, increases in dose, pain, dope sickness, and the need to supplement with additional opioids.

RESULTS

Four hundred five methadone maintenance treatment patients from fifty harm reduction sites across British Columbia reported transitioning to Methadose™ in February 2014. The majority (n = 258; 73.1 %) heard about the formulation change from their methadone provider or pharmacist. Adjusted models show worse taste was positively associated with reporting an increasing dose (OR = 2.46; CI:1.31-4.61), feeling more dope sick (OR = 3.39; CI:1.88-6.12), and worsening pain (OR = 4.65; CI:2.45-8.80). Feeling more dope sick was positively associated with dose increase (OR = 2.24; CI:1.37-3.66), and supplementing with opioids (OR = 8.81; CI:5.16-15.05).

CONCLUSIONS

Methadone maintenance treatment policy changes in British Columbia affect a structurally vulnerable population who may be less able to cope with transitions and loss of autonomy. There may be a psychosocial component contributing to the perception of Methadose™ tasting worse, and increased dope sickness, pain, and dose. Our study shows the pronounced negative impacts medication changes can have on patients without informed, coordinated efforts. We stress the need to engage all stakeholders allowing for communication about the reasons, risks and consequences of medication policy changes and provision of additional psychosocial support.

Pain and the thermally injured patient-a review of current therapies

Thermally injured patients experience tremendous pain from the moment of injury to months or years after their discharge from the hospital. Pain is therefore a critical component of proper management of burns. Although the importance of pain is well recognized, it is often undertreated. Acute uncontrolled pain has been shown to increase the incidence of mental health disorders and increase the incidence of suicide after discharge. Long-term poor pain control leads to an increase in the incidence of persistent pain. Most burn centers have used opioids as the mainstay analgesic, but recently, the significant side effects of opioids have led to the implementation of new and combined therapeutics. Pharmacological agents such as gabapentin, clonidine, dexmedetomidine, and ketamine have all been suggested as adjuncts to opioids in the treatment of burn pain. Nonpharmacological therapies such as hypnosis, virtual reality devices, and behavioral therapy are also essential adjuncts to current medications. This review aims at identifying the currently available pharmacological and nonpharmacological options for optimal pain management in the adult burn population.

Animal studies trigger new insights on the use of methadone maintenance

BACKGROUND

Although steady-state methadone (SSM) treatment is mainly used for opioid addiction, some clinical studies indicate that it also reduces cocaine abuse in opioid-dependent individuals.

OBJECTIVE/METHODS

To present evidence suggesting that SSM may be useful in the treatment of cocaine addiction without pre-existing opioid dependence. We review studies in animals investigating the effects of SSM on behaviors motivated by cocaine and on cocaine-induced alterations of genes expression in the rat brain.

CONCLUSION

SSM reduces cocaine intake, blocks cocaine seeking and normalizes expression of genes known to regulate cocaine seeking. These findings suggest that SSM could be an effective pharmacological agent to assist cocaine detoxification and prevention of relapse to cocaine abuse in individuals not co-dependent on opioid.

The medical consumption of opioids in Colombia, 1997-2007

The World Health Organization classifies opioid analgesics as essential medicines in the treatment of severe pain and recommends their increased availability. The combination of availability, training of professionals, and a legal framework granting access to these medicines has led to a sharp increase in the consumption of morphine and other opioids in developed countries. However, in Colombia, consumption of opioid analgesics appears to fail to meet patient needs. To analyze the current trends in medical consumption of opioids in Colombia, the numbers of defined daily doses of opioid analgesics for total inhabitants and the population that died of cancer between 1997 and 2007 were calculated and compared. The import of raw materials and medicines varied greatly every year. However, from 2003, a trend toward the increased consumption of morphine, hydromorphone, and methadone was observed. Availability was inconsistent and opioid consumption showed an increase when calculated for total inhabitants and for cancer deaths. The unreliable availability of opioid analgesics may be responsible for their limited consumption. Chronic underuse and a trend toward increased consumption have been confirmed. Monitoring of consumption to promote rational use is recommended.

Slow-release oral morphine for maintenance treatment of opioid addicts intolerant to methadone or with inadequate withdrawal suppression

AIMS

Evaluation of the efficacy, safety and acceptability of slow-release oral morphine (SROM) in opioid addicts intolerant to methadone or with inadequate withdrawal suppression.

DESIGN

Prospective, open, non-comparative multi-centre study.

SETTING

Twelve out-patient Centres for Prevention and Treatment of Drug Addiction in Slovenia.

PARTICIPANTS

Male and female opioid addicts (age>18 years) under methadone maintenance therapy requiring a change of treatment in order to continue more effectively with maintenance.

INTERVENTIONS

Maintenance therapy with methadone was switched to once-daily SROM.

MEASUREMENTS

Efficacy evaluations were based on the reduction of side effects and on the degree of suppression of opiate craving, signs and symptoms of withdrawal. In addition, self-reported somatic and psychic symptoms (SCL-27) as well as World Health Organization quality of life-related (WHO QOL) parameters were monitored.

FINDINGS

Thirty-nine subjects intolerant to methadone and 28 subjects showing inadequate withdrawal suppression under methadone>or=90 mg/day were included as two separate groups in the efficacy analyses. Treatment was switched easily from methadone to SROM on a 1:8 ratio. Four-week SROM treatment resulted in significant reduction of side effects reported under methadone. Signs and symptoms of opioid withdrawal as well as craving for opiates were improved significantly in patients with inadequate response to methadone. Physical and psychological wellbeing improved significantly under SROM treatment. SROM was tolerated very well.

CONCLUSIONS

Maintenance treatment with SROM appears to be a clinically useful alternative treatment in subjects not tolerating methadone or with inadequate withdrawal suppression.

Actual and potential drug interactions associated with methadone

OBJECTIVE

To identify and characterize methadone-related drug interactions, as well as factors accounting for the variability in manifesting these interactions clinically.

DESIGN

Systematic review of the primary literature.

METHODS

Over 200 articles, reports of clinical trials, and case reports were reviewed. Studies and case reports were included if they revealed either quantitative or qualitative methods to identify, evaluate severity of, or compare methadone-related drug interactions.

RESULTS OF DATA SYNTHESIS

The evidence base associated with methadone drug interactions is underdeveloped in general, as the majority of references found were case reports or case series. Most of the studies and reports focused on inpatients receiving methadone maintenance treatment (MMT) that were between 20 and 60 years of age, taking 200 mg/day of methadone or less. Evidence supporting the involvement of lesser known cytochrome P450 enzymes such as 2B6 is emerging, which may partially explain the inconsistencies previously found in studies looking specifically at 3A4 in vitro and in vivo. Genetic variability may play a role in the pharmacokinetics and pharmacodynamics of many medications, including methadone.

CONCLUSIONS

Drug interactions associated with methadone and their clinical significance are still poorly understood in general. Many tertiary drug information references and review articles report interactions associated with methadone in a general sense, much of which is theoretical and not verified by case reports, much less well-designed clinical trials. The majority of drug interaction reports that do exist were performed in the MMT population, which may differ significantly from chronic pain or cancer pain populations.

Feasibility and outcome of substitution treatment of heroin-dependent patients in specialized substitution centers and primary care facilities in Germany: a naturalistic study in 2694 patients

BACKGROUND

In many countries, buprenorphine and methadone are licensed for the maintenance treatment (MT) of opioid dependence. Despite many short-term studies, little is known about the long-term (12-month) effects of these treatments in different settings, i.e. primary care-based (PMC) and specialized substitution centers (SSCs).

OBJECTIVES

To describe over a period of 12 months: (1) mortality, retention and abstinence rates; (2) changes in concomitant drug use, somatic and mental health; and (3) to explore differences between different types of provider settings.

METHODS

12-Month prospective-longitudinal naturalistic study with four waves of assessment in a prevalence sample of N=2694 maintenance patients, recruited from a nationally representative sample of N=223 substitution physicians.

RESULTS

The 12-month retention rate was 75%; the mortality rate 1.1%. 4.1% of patients became "abstinent" during follow-up. 7% were referred to drug-free addiction treatment. Concomitant drug use decreased and somatic health status improved. No significant improvements were observed for mental health and quality of life. When controlling for initial severity, small PMC settings revealed better retention, abstinence and concomitant drug use rates.

CONCLUSION

The study underlines the overall 12-month effectiveness of various forms of agonist MT. Findings reveal relatively high retention rates, low mortality rates, and improvements in most 12-month outcome domains, except for mental health and quality of life. PMC settings appear to be a good additional option to improve access to MTs.

Blockade of morphine-induced behavioral sensitization by a combination of amisulpride and RB101, comparison with classical opioid maintenance treatments

BACKGROUND AND PURPOSE

Maintenance treatments with methadone or buprenorphine are more or less efficient procedures for helping heroin addicts to stop or reduce drug abuse. Another approach to treat opiate dependence could be to target the endogenous opioid system by enhancing the effects of enkephalins by protecting them from enzymic degradation by the dual peptidase inhibitor RB101.

EXPERIMENTAL APPROACH

As chronic treatment with the dopamine D2 antagonist amisulpride facilitates RB101-induced behavioral effects, we chose in this study to treat mice previously sensitized to the hyperlocomotor effects induced by morphine with a combination of amisulpride and RB101.

KEY RESULTS

Expression of morphine-induced locomotor sensitization was abolished after combined treatment with amisulpride (20 mg x kg(-1), i.p.) and RB101 (80 mg x kg(-1), i.p.), whereas these drugs were not effective when used alone. We then compared these results with the effects of amisulpride combined with buprenorphine (0.1 mg x kg(-1), i.p.) or methadone (2.5 mg x kg(-1), i.p.) upon morphine-induced behavioral sensitization. Whereas the combination of amisulpride and buprenorphine partially blocked the expression of morphine sensitization, amisulpride+methadone was not effective in this paradigm.

CONCLUSIONS AND IMPLICATIONS

The combination of amisulpride+RB101 appears to be very efficient in blocking the expression of morphine-induced behavioral sensitization. This could reflect a reinstatement of a balance between the function of the dopamine and opioid systems and could represent a new approach in maintenance treatments for opiate addiction.

Methadone treatment of chronic non-malignant pain and opioid dependence - A long-term follow-up

Iatrogenic opioid addiction among chronic pain patients was the initiative for starting a methadone programme for pain patients at the University Hospital of Uppsala. The aims were to improve pain relief and quality of life in pain patients with problematic opioid use and to investigate background factors explaining problems with opioid use.

METHODS

Records of all 60 patients included in the methadone programme 1994-2002 were studied. An interview was done after a mean of 34 months of methadone treatment regarding pain relief, quality of life and side effects on 48 patients.

RESULTS

Titration of oral methadone mixture in daily doses ranging from 10 to 350 mg (mean 99.5 mg) was done on all patients. Background factors were low back and musculoskeletal pain in 40%, psychiatric disease in 68%, and substance use disorder in 32% of the patients. Before methadone treatment all patients were on sick leave. After treatment five patients returned to work. Ten patients failed treatment, 4 due to intractable nausea, 4 to drug diversion, 1 because of methadone related arrhythmia and 1 because of insufficient analgesia. Pain relief was rated good by 75% and moderate by 25% of the patients. Global quality of life was rated at mean of 50(0-100), which favourably compares with Swedish chronic pain patients mean 33(0-100).

CONCLUSION

A structured methadone programme can be used for treating chronic pain patients with opioid dependence improving pain relief and quality of life. However, side effects and serious adverse events may limit the beneficial effects of the method.

Measurement of QTc in patients receiving chronic methadone therapy

Recent reports suggest that methadone may prolong the QTc interval and cause torsades de pointes. This study was conducted to evaluate the prevalence of QTc prolongation during oral methadone therapy and identify factors associated with prolongation. Patients receiving oral methadone as treatment for chronic pain or addiction were eligible for the study. One hundred four patients who were receiving > or = 20 mg methadone per day for > or = 2 weeks underwent electrocardiograms to measure QTc interval duration. Sixty-three (61%) patients were male and 63 (61%) were receiving methadone maintenance for opioid addiction. The mean (+/- SD) age was 45.3 +/- 9.4 years. The median (range) methadone dose was 110 mg/day (20-1200 mg/day); median (range) number of months on methadone was 12.5 months (1-444 months). The median (range) QTc interval was 428 msec (396-494 msec). Thirty-three percent had QTc prolongation (males 40%, females 20%; P=0.03). No patient had a QTc longer than 500 msec. Significant dose response was observed in males on methadone <12 months (rho=0.60, P=0.02). Our study suggests that methadone may prolong the QTc interval in specific subpopulations but poses little risk of serious prolongation.

Pharmacologic management of neuropathic pain

The mechanisms underlying the pathogenesis of neuropathic pain are complex but are gradually coming to light. Agents that have been found effective in a variety of neuropathic pain conditions include drugs that act to modulate (a) sodium or calcium channels, (b) N-methyl-D-aspartate receptors, (c) norepinephrine or serotonin reuptake, (d) opioid receptors, and (e) other cellular processes. Clinical trials have primarily evaluated these treatments for postherpetic neuralgia and painful diabetic neuropathy, the two most common types of neuropathic pain. Nonetheless, the identification of effective treatment regimens remains challenging, often because multiple mechanisms may be operating in a given patient giving rise to the same symptom. Alternatively, a single mechanism may be responsible for multiple symptoms. Currently available diagnostic tools are inadequate to determine the best treatment using a mechanism-based model. Clinically, drug treatment of neuropathic pain is often a matter of treatment trials. This article presents a summary of available clinical information on first-line and lesser-known treatments for neuropathic pain.

Buprenorphine and methadone in the treatment of opioid dependence: methods and design of the COBRA study

Buprenorphine and methadone are the two established substitution drugs licensed in many countries for the treatment of opioid dependence. Little is known, however, about how these two drugs are applied and how they work in clinical practice. In this paper we present the aims, methods, design and sampling issues of a collaborative multi-stage epidemiological study (COBRA) to address these issues. Based on a nationally representative sample of substitution physicians, the study is designed as an observational, naturalistic study, consisting of three major parts. The first part was a national survey of substitution doctors (prestudy, n = 379 doctors). The second part was a cross-sectional study (n = 223 doctors), which consisted of a target-week assessment of 2,694 consecutive patients to determine (a) the severity and problem profiles and treatment targets; (b) the choice and dosage scheme of the substitution drug; (c) past and current interventions, including treatment of comorbid hepatitis C; and (d) cross-sectional differences between the two drugs with regard to comorbidity, clinical course, acceptance/compliance and social integration. The third part consists of a prospective-longitudinal cohort study of 48 methadone-treated and 48 buprenorphine-treated patients. The cohort is followed up over a period of 12 months to investigate whether course and outcome of the patients differ by type or treatment received in terms of clinical, psychosocial, pharmaco-economic and other related measures. The response rate among substitution doctors was 57.1%; that among eligible patients was 71.7%. Comparisons with the federal registers reveal that the final samples of doctors and patients may be considered nationally representative with regard to regional distribution, training, type of setting as well as the frequency of patients treated with buprenorphine or methadone. The COBRA study provides a unique comprehensive database, informing about the natural allocation and intervention processes in routine care and about the course and outcome of patients treated with buprenorphine or methadone.

Methadone and the hospice patient: prescribing trends in the home-care setting

OBJECTIVE

To identify frequency and utilization patterns of methadone by hospice patients in the home-care setting.

PATIENTS AND SETTING

All hospice patients admitted to a North American palliative care specialty pharmacy and dispensed methadone from November 1, 2001 to October 31, 2002 were analyzed. We also analyzed all hospice patients dispensed long-acting opioids during that same time period.

DESIGN

A retrospective analysis of the pharmacy database was performed for patients dispensed methadone. Data was compared to the long acting opioid cohort to be able to identify any difference in terminal diagnoses present, and the presence of neuropathic pain in both groups. Methadone daily dosage was also analyzed during this study.

RESULTS

Four hundred sixteen hospice patients were dispensed methadone over a twelve-month period of time. For comparison, 21,219 patients were prescribed a long-acting opioid preparation (sustained-release morphine, sustained-release oxycodone, or transdermal fentanyl). The most common terminal diagnosis for both groups was lung carcinoma. The distribution of terminal diagnoses was similar in both groups. The group prescribed methadone was found to have a higher incidence of neuropathic pain (30.5% of patients) when compared to the long-acting opioid group (16.9%). Most patients (61.3%) were prescribed daily methadone doses of 100 mg or less.

CONCLUSIONS

Despite its potential clinical and economic benefits, methadone is not commonly prescribed for the hospice patient in the home-care setting. Clinicians may be more aware of the usefulness of methadone in the treatment of neuropathic pain.

Medico-legal rounds: medico-legal issues and alleged breaches of "standards of medical care" in opioid rotation to methadone: a case report

OBJECTIVES

The objectives of this medico-legal case report were the following: 1) To present an example of a medico-legal problem that developed as a result of a decision to rotate a chronic pain patient (CPP) to methadone in order to taper the CPP from oxycodone; 2) To present both the plaintiff's and defendant's expert witnesses' opinions as to if and where the care of that patient fell below the "standard of medical care;" and 3) Based on these opinions, to develop some recommendations on how, in the future, pain medicine physicians and other physicians should proceed, in order to avoid allegations of breach of "standards of care" when using methadone.

METHODS

This is a case report of a CPP treated at a regional hospital pain clinic. Methadone rotation was used in order to taper the CPP from oxycodone because of addictive disease.

RESULTS

During the rotation process, the CPP expired. This had medico-legal consequences. Expert witnesses differed as to whether methadone caused the death.

CONCLUSION

Pain physicians should proceed with caution in using methadone for opioid rotation.