The effect of oral methadone on the QTc interval in advanced cancer patients: a prospective pilot study

Low-dose add-on methadone for cancer pain management: a retrospective analysis of 102 Japanese patients

BACKGROUND

Methadone was introduced in 2013 for the treatment of intractable cancer pain in Japan and is indicated for patients receiving opioid doses ≧60 mg/day as an oral morphine equivalent. Low-dose (≦10 mg/day) add-on methadone to prior opioids has been reported from European countries to successfully relieve various types of intractable cancer pain; however, there are few reports of such use in Japan. The aim of this study was to analyze more than a hundred cases with low-dose add-on methadone to treat intractable pain in Japanese cancer patients.

METHODS

All cases in which 5 or 10 mg/day of methadone was added to prior opioids by the Palliative Care Team or Division of Palliative Medicine in our hospital during the period between April 2016 and September 2023 were extracted and analyzed retrospectively on electrical medical charts.

RESULTS AND CONCLUSIONS

A total of 102 cases were extracted with a male-to-female ratio of 60:42, and the age (mean ± SD) was 62.8 ± 14.7 years old. Methadone was introduced in an inpatient setting to 86 patients. The major pathologies that caused intractable pain were spinal metastases in 48, pelvis or pelvic floor lesions in 29 and pleural and/or chest wall lesions in 16. The most common mechanism of pain was the mixture of somatic and neuropathic components. The major opioids administered prior to methadone included tapentadol in 46 patients, hydromorphone in 36 and oxycodone in 19. The dose of the prior opioids [median, (interquartile range: IQR)] was 97, (62.8-167.3) (range: 15-1313) mg/day of oral morphine equivalent. Radiotherapy, chemotherapy and nerve blocks were performed as concomitant therapies in 48, 22 and 11 patients, respectively (with some overlap). The number of rescue doses [median (IQR)] was significantly decreased from three (two to five) on the day before methadone to one (zero to four) after seven days from methadone initiation. The side effects leading to discontinuation of methadone were drowsiness in three cases, nausea in three cases and dizziness in one case (with some overlap). Compared with complete switching from other opioids, low-dose add-on methadone can reduce the possibility of major dose discrepancies and can be quickly adjusted by combined opioid reduction/increase. Low-dose add-on methadone can be an effective and safe method for intractable cancer pain.

A Case of Esophagogastric Junction Cancer Treated with Pain Control by Administering Methadone Tablets Through a Gastrostomy

Introduction: Methadone is used to treat intractable cancer pain when other opioid analgesics are ineffective. Methadone tablets may be difficult to administer in cases of gastrointestinal passage obstruction. However, changing the route of methadone tablet administration is possible. Case Description: The patient, diagnosed with esophagogastric junction cancer with multiple metastases, continued to receive methadone tablets even after not being longer able to take oral medication. Method: Methadone tablets were administered using a simple suspension method via gastrostomy. We measured the respiratory rate during sleep daily. We also measured weekly QTc values using a 12-lead electrocardiogram and methadone blood concentration periodically. No side effects were observed. Conclusion: Using a simple suspension method to administer methadone is a safe pain management method when accompanied by careful monitoring. To date, no study has examined the tube administration safety of methadone tablets. Thus, this case report is of important clinical significance.

Routine Monitoring of QTc Interval as a Barrier for Efficient Use of Methadone in Palliative Care

BACKGROUND

Methadone is a commonly prescribed opioid amongst cancer patients. It has unique pharmacological properties which can benefit in treating complex pain syndromes and neuropathic pain. However, strict guidelines have been created in a generalized manner for chronic pain and long-term survival patients. These guidelines, such as QT interval monitoring can lead to limitations for methadone use in patients with comfort-associated goals. We present two cases of patients with metastatic cancer who were treated for pain with methadone and had to undergo opioid rotation due to abnormal QT intervals.

CASE DESCRIPTION

Case one was a female with open ulcerated wounds due to metastatic breast cancer who presented with uncontrolled pain on her current opioid regimen. She achieved pain relief when rotated to methadone but a repeat electrocardiogram a few months later showed QTc prolongation. She underwent opioid rotation with different medications, but her pain remained poorly controlled. Case two was a female with poorly controlled pain in the setting of bilateral breast cancer. She presented with concerns for opioid-induced neurotoxicity and was rotated to methadone. She achieved optimal pain relief. A few weeks later, her machine read QT interval was prolonged and she was rotated off methadone. The electrocardiogram was manually read which showed a normal QT interval and she was restarted on methadone with pain relief.

CONCLUSION

In the palliative care setting, monitoring QTc per chronic pain guidelines may lead to uncontrolled pain and a significant impact on quality of life.

A case with a trend of QT interval prolongation due to the introduction of methadone to a pancreatic cancer patient on levofloxacin

BACKGROUND

As methadone can prevent the development of opioid resistance, it has application in alleviating cancer-related pain that proves challenging to manage with other opioids. QT interval prolongation is a serious side effect of methadone treatment, with some reported deaths. In particular, owing to the increased risk of QT interval prolongation, caution should be exercised when using it in combination with drugs that also prolong the QT interval.

CASE PRESENTATION

This study presents a case in which methadone was introduced to a patient (a man in his 60s) already using levofloxacin, which could prolong the QT interval-a serious side effect of methadone treatment-and whose QTc value tended to increase. Given that levofloxacin can increase the risk of QT interval prolongation, we considered switching to other antibacterial agents before introducing methadone. However, because the neurosurgeon judged that controlling a brain abscess was a priority, low-dose methadone was introduced with continuing levofloxacin. Owing to the risks, we performed frequent electrocardiograms. Consequently, we responded before the QTc increased enough to meet the diagnostic criteria for QT interval prolongation. Consequently, we prevented the occurrence of drug-induced long QT syndrome.

CONCLUSIONS

When considering the use of methadone for intractable cancer pain, it is important to eliminate possible risk factors for QT interval prolongation. However, as it may be difficult to discontinue concomitant drugs owing to comorbidities, there could be cases in which the risk of QT interval prolongation could increase, even with the introduction of low-dose methadone. In such cases, frequent monitoring, even with simple measurements such as those used in this case, is likely to prevent progression to more serious conditions.

Prevention, diagnosis, and treatment of opioid use disorder under the supervision of opioid stewardship programs: it's time to act now

The third opium war may have already started, not only due to illicit opioid trafficking from the Golden Crescent and Golden Triangle on the international front but also through indiscriminate opioid prescription and opioid diversion at home. Opioid use disorder (OUD), among unintentional injuries, has become one of the top 4 causes of death in the United States (U.S.). An OUD is defined as a problematic pattern of opioid use resulting in clinically significant impairment or distress, consisting of 2 or more of 11 problems within 1 year, as described by the Diagnostic and Statistical Manual for Mental Disorders, Fifth Edition. Observation of aberrant behaviors of OUD is also helpful for overworked clinicians. For the prevention of OUD, the Opioid Risk Tool and the Current Opioid Misuse Measure are appropriate screening tests before and during opioid administration, respectively. Treatment of OUD consists of 3 opioid-based U.S. Food and Drug Administration-approved medications, including methadone, buprenorphine, and naltrexone, and non-opioid-based symptomatic medications for reducing opioid withdrawal syndromes, such as α2 agonists, β-blockers, antidiarrheals, antiemetics, non-steroidal anti-inflammatory drugs, and benzodiazepines. There are at least 6 recommendable guidelines and essential terms related to OUD. Opioid stewardship programs are now critical to promoting appropriate use of opioid medications, improving patient outcomes, and reducing misuse of opioids, influenced by the successful implementation of antimicrobial stewardship programs. Despite the lack of previous motivation, now is the critical time for trying to reduce the risk of OUD.

Demand-only patient-controlled analgesia for treatment of acute vaso-occlusive pain in sickle cell disease

BACKGROUND

Sickle cell disease (SCD) is a chronic illness that is associated with frequent admissions for vaso-occlusive episodes (VOE). Opioids are frequently utilized in pain management, but dosing is often provider dependent. Opioids cause both short-term and long-term side effects, so the minimal effective dose is desired. This study examined demand-only patient-controlled analgesia (PCA) in pediatric patients.

METHODS

A new clinical practice guideline (CPG) for a single institution was implemented, which eliminated basal infusion dosing for PCAs on hospital admission. The primary aim of this retrospective study was to evaluate length of stay (LOS) before and after implementation of a CPG of demand-only PCA and, in a selected subpopulation, addition of short-term methadone. Secondary aims included opioid utilization, acute chest syndrome (ACS), and hypoxia. Inclusion criteria included SCD, ≤21 years of age, uncomplicated VOE admission, and ≥ 3 and ≤ 8 hospital admissions for SCD pain control within one calendar year.

RESULTS

LOS decreased postintervention (7.2 ± 5.1 vs 4.5 ± 3.8 days, P < 0.001). Mean total opioid utilization in morphine equivalents mg/kg markedly decreased between the cohorts (13.3 ± 33.8 vs 3.6 ± 3.0, P < 0.001). ACS (21.9% vs 2.8%, P = 0.004) and hypoxia (28% vs 6.9%, P< 0.001) decreased significantly as well.

CONCLUSION

Bolus PCA dosing of opioids resulted in decreased LOS and reductions in opioid utilization, hypoxia, and ACS.

The Introduction and Experiences of Methadone for Treatment of Cancer Pain at a Low-resource Governmental Cancer Center in India

Objectives

This study aimed to describe the clinical experience of the health-care professionals (HCPs) responsible for the introduction of methadone, for the treatment of complex cancer pain, at a low-resource hospital in India in a patient-group, burdened by illiteracy, and low socio-economic status.

Materials and Methods

Ten HCPs: Four medical doctors, four nurses, one pharmacist, and one hospital administrator were interviewed. The interviews are examined using a qualitative conventional content analysis.

Results

The interviews showed a confidence amongst the HCPs, responsible for the safe introduction of methadone in a stressful and low-resource surrounding, to patients with cancer pain and the different aspects of methadone, as initiation, titration, and maintenance of treatment.

Conclusion

Introduction of methadone for cancer pain management is safe and feasible although low resources in a challenging hospital setting and care environment.

Accuracy of a single-lead mobile smartphone electrocardiogram for QT interval measurement in patients undergoing maintenance methadone therapy

STUDY OBJECTIVE

Methadone is associated with QT interval prolongation and torsades de pointes. Expert panel recommendations advocate a pre-methadone electrocardiogram (ECG) and another ECG at 30 days of therapy in patients with risk factors. Some guidelines recommend a pre-methadone ECG and routine ECG monitoring in all methadone patients, but this is controversial due to the resources required. Availability of a convenient, less resource-intensive method of ECG monitoring for patients taking methadone is desirable. The objective of this study was to assess the accuracy of a handheld smartphone ECG (iECG) for QT measurement in patients on maintenance methadone therapy in an urban opioid treatment program.

DESIGN

Prospective study.

SETTING

Urban opioid treatment program.

PATIENTS

n = 115 patients in normal sinus rhythm who were on steady-state maintenance methadone therapy INTERVENTION: Patients (n = 115) underwent a simultaneous 12-lead ECG and a single-lead iECG.

MEASUREMENTS AND MAIN RESULTS

The first three QT and RR intervals from lead II of the 12-lead ECG and simulated lead I from the iECG were compared using the Bland-Altman analysis of measurement agreement. Mean [± standard deviation) age was 34 ± 11 years; 71% were female, 75% were white. Compared to the 12-lead ECG, the iECG was associated with a QTc bias of - 0.14 ms (SD = 12 ms, 95% CI = -2.4 to 2.1 ms). The absolute mean difference in QTc between the two methods was 9.5 ± 7.1 ms. For identification of patients with methadone-associated QTc prolongation, the iECG performed moderately well [c-statistic 0.97 (95% CI 0.91-0.99); sensitivity and specificity 75% (95% CI 43-95%) and 99% (95% CI 94-99%), respectively]. The positive and negative likelihood ratios of the iECG for identifying patients with methadone-associated QTc prolongation were 77.25 (95% CI 10.69 to 558.18) and 0.25 (95% CI 0.09 to 0.67), respectively, while the positive and negative predictive values were 90% (95% CI 56-99%) and 97% (95% CI 92-99%), respectively. The accuracy of the iECG for identifying patients with QTc prolongation was 97% (95% CI 91-99%).

CONCLUSION

A handheld smartphone ECG is accurate for QT interval measurement in patients taking maintenance methadone therapy, and its performance is moderately good for identifying patients with methadone-associated QTc prolongation.

The Use of Methadone in Adult Patients with Cancer Pain at a Governmental Cancer Center in India

Background:

Management of cancer-related pain relies on the access to opioids. When regular opioids as morphine are not tolerated or are insufficient, adjuvant opioids as methadone are an affordable and effective analgesic.

Aim:

The aim of the project was to describe the pattern of use and clinical experiences of methadone in patients with cancer-related pain at a low-resource hospital in Hyderabad, one of few Indian cancer centers with permission to prescribe methadone.

Methods:

Medical records of all patients who had been prescribed methadone, September 9, 2017 and November 19, 2019 were studied retrospectively. Data on analgesic treatment and opioid side effects were analyzed.

Results:

A total of 93 adult cancer patients were included in the study. A majority of patients (79%) were prescribed opioid analgesic, mainly morphine, before methadone introduction. The initial daily dose of methadone ranged between 5 and 22.5 years and in the vast majority of the patients 5 mg, divided in two daily administrations. A good analgesic effect, with decreased pain, was reported in 60% of the patients. No severe side effects were reported.

Conclusions:

In this study, methadone as a primary opioid was used with a good analgesic effect for cancer pain in a low-resource setting. Indication for methadone was mainly uncontrolled pain with a regular opioid treatment. No severe adverse effects were reported. Further research and prospective studies are needed on methadone treatment in low-resource settings to establish the robust guidelines to support prescribing physicians.

The Use of Methadone in Pediatric Cancer Pain - A Retrospective Study from a Governmental Cancer Center in India

Background:

The management of cancer-related pain relies on access to opioids. When regular opioids are not tolerated, or are insufficient, methadone is an affordable and effective analgesic.

Aim:

The aim of the project was to describe the pattern of use and clinical experience of methadone in pediatric cancer pain at a governmental cancer hospital in Hyderabad, one of the four Indian cancer centers with permission to prescribe methadone.

Methods:

This was a retrospective study of medical records of all children, under the age of 18, who had been prescribed methadone from September 9, 2017, to November 19, 2019. Data on analgesic effect, prior and concomitant analgesic treatment, opioid side effects, and the handling of methadone were analyzed.

Results:

A total of 11 children were identified and studied. Methadone was introduced mainly when pain was uncontrolled by regular opioids. Initial daily doses ranged from 1 to 15 mg. The duration of treatment ranged from 7 to 307, with a median of 50 days in the nine patients where treatment exceeded one single dosage. Good analgesic effect was reported in 5/9 children, unchanged from previous analgesic treatment in three patients and without any effect in one child. No severe side effects were reported.

Conclusion:

Low-dose methadone in the treatment of pediatric cancer pain at a low-resource cancer center was safe and well tolerated by the patients, with long treatment durations. It was safely managed, administered with single to double daily dosages, hence easy for patients and family to handle, and an affordable treatment option.

Population Pharmacokinetics of Methadone after Oral Administration in Japanese Patients with Cancer-Related Pain

Methadone tablets were approved for use in Japan in March 2013. The metabolism of methadone is complex and executed mainly by the cytochromes, CYP3A4 and CYP2B6. The aim of this study was to evaluate the pharmacokinetics of methadone upon oral administration in Japanese patients who experienced cancer-related pain. The concentration of the drug in blood samples was measured in 25 patients undergoing methadone therapy, and the factors leading to variations were investigated. A population pharmacokinetic analysis was evaluated using the Phoenix® NLME^TM software. Based on this, the ALBI (albumin-bilirubin) score was identified as a significant factor that could be used to assess variations in the serum concentration of methadone, which was then incorporated into the following final model formula: clearance (L/h) = 5.38 × (ALBI score/-2.139)^1.88. The results of these pharmacokinetic parameters suggested that, in clinical use, the dose of methadone should be reduced if liver function declined in patients with cancer-related pain.

Switching Ratio from Parenteral to Oral Methadone 1:1.2 Is Safer Compared with Ratio 1:2 in Patients with Controlled Cancer Pain: A Multicenter Randomized-Controlled Trial (RATIOMTD-010810)

Background: The most commonly used switching ratio from parenteral to oral methadone is 1:2. Methadone is highly bioavailable and a lower ratio might result in similar analgesia with less toxicity. Objective: To compare success and side effects with two ratios from parenteral to oral methadone: 1:2 versus 1:1.2 in hospitalized patients with cancer pain. Design: A multicenter double-blind randomized clinical trial. Settings/Particiants: Inpatients with well-controlled cancer pain with parenteral methadone requiring rotation to the oral route. Measurements: Outcomes included pain intensity (Brief Inventory Pain), opioid toxicity (Common Toxicology Criteria for Adverse Events), and methadone dose. Success was defined as no toxicity with good pain control at 72 hours. Results: Thirty-nine of forty-four randomized patients were evaluable: 21 in ratio 1:2 and 18 in ratio 1:1.2. Seventy-one percent male. Median age 65 years. No significant differences in basal clinical characteristics between both groups. Median methadone dose pre/post switching was 24.5 mg ±13.5 and 49 mg ±27.3 for ratio 1:2, versus 23.3 mg ±9.4 (p: not significant) and 28 mg ±11.3 (p < 0.01) for ratio 1:1.2. Pain was well controlled without differences between both ratios. Drowsiness at day +1 (p < 0.017) and myoclonus at day +3 (p < 0.019) were more prevalent in group 1:2. Success was observed in 12 patients in ratio 1:2 versus 18 in ratio 1:1.2 (p < 0.001). Methadone side effects were observed in 12 patients in ratio 1:2 (mainly neurotoxicity symptoms) versus 2 in ratio 1:1.2 (p < 0.005). Conclusion: Ratio 1:1.2 when changing from parenteral to oral methadone resulted in lower toxicity and no difference in analgesia. More conservative dose adjustment during methadone route change should be considered. European Clinical Trials Register (EudraCT No. 2010-024092-39).

Integrating in vitro data and physiologically based kinetic modeling-facilitated reverse dosimetry to predict human cardiotoxicity of methadone

Development of novel testing strategies to detect adverse human health effects is of interest to replace in vivo-based drug and chemical safety testing. The aim of the present study was to investigate whether physiologically based kinetic (PBK) modeling-facilitated conversion of in vitro toxicity data is an adequate approach to predict in vivo cardiotoxicity in humans. To enable evaluation of predictions made, methadone was selected as the model compound, being a compound for which data on both kinetics and cardiotoxicity in humans are available. A PBK model for methadone in humans was developed and evaluated against available kinetic data presenting an adequate match. Use of the developed PBK model to convert concentration–response curves for the effect of methadone on human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) in the so-called multi electrode array (MEA) assay resulted in predictions for in vivo dose–response curves for methadone-induced cardiotoxicity that matched the available in vivo data. The results also revealed differences in protein plasma binding of methadone to be a potential factor underlying variation between individuals with respect to sensitivity towards the cardiotoxic effects of methadone. The present study provides a proof-of-principle of using PBK modeling-based reverse dosimetry of in vitro data for the prediction of cardiotoxicity in humans, providing a novel testing strategy in cardiac safety studies.

Prevalence of QTc Prolongation in Patients With Advanced Cancer Receiving Palliative Care-A Cause for Concern?

CONTEXT

Medications commonly used for symptom control along with other known risk factors have the potential to prolong ventricular repolarization as measured by the QT interval (the time from the start of the Q wave to the end of the T wave) on a standard electrocardiogram (ECG).

OBJECTIVES

To document the prevalence of a prolonged QT interval corrected for heart rate (QTc) interval in the palliative/oncology setting, compare automatic ECG QTc measurements with manual readings and identify any correlation between QTc prolongation and the use of drugs or other risk factors.

METHODS

A convenience sample of consecutive patients with cancer, admitted under or known to the palliative/supportive care teams in two metropolitan hospitals, and willing to provide an ECG recording and basic demographic information including QTc risk factors were included. Both automated and manually calculated QTc intervals were recorded. Multivariable analysis was used to determine risk factors independently associated with prolonged QTc intervals.

RESULTS

Of the 389 participants, there was a significant difference in mean QTc between sites using automated but not manual calculations. Manual readings were therefore used with predetermined cutoffs of 0.44 seconds (males) and 0.46 seconds (females). Seventy-two (18.5%) of the participants had a prolonged QTc with six (1.5%) having a prolongation of >0.50 seconds. At-risk drugs were being taken by 218 participants (56.0% of total cohort). Factors shown to be associated with QTc prolongation included age, gender, performance status, and hypocalcemia. No specific medication was associated with increased risk.

CONCLUSION

Although almost 20% of patients receiving palliative care had prolongation of QTc, the possibility of serious consequences appeared to be low despite the frequent occurrence of risk factors.

How to Use Methadone in an Era of an Opioid Epidemic

OPINION STATEMENT

The opioid epidemic is one of the most important public health crises as opioid-related deaths have become a leading cause of accidental death in the USA. Various efforts have been made to understand how to safely and appropriately prescribe opioids for patients with chronic pain, including those with cancer-related pain. We find the guidelines proposed by the Expert Consensus White Paper on the use of methadone to be current, comprehensive, and practical. While methadone is a complex medication with unique pharmacokinetics and pharmacodynamics, it remains a superior choice for many patients with cancer pain given its cost and applicability in a variety of situations. Methadone should be prescribed in the context of experienced clinicians as well as an interdisciplinary team. At a critical time when preventing opioid-related deaths is a priority, we recommend implementing additional precautions for monitoring including universal screening for risk of non-medical opioid use, education on proper storage and disposal, as well as discussing a plan with patients and caregivers in the case of serious complications such as opioid overdose.

QT Interval Prolongation in the Pediatric Oncologic Population on Methadone

Studies have been conducted on adults prescribed with methadone to determine the necessary frequency of QTc monitoring but no consensus has been reached and no similar research has been conducted in the pediatric population. The objective of this retrospective study was to determine the occurrence rate of QTc interval prolongation associated with methadone use in a pediatric oncologic population. In total, 18% of patients developed QTc interval prolongation. These patients had longer baseline QTc intervals and were on more QTc interval-prolonging medications. Our data suggest that these variables may be able to risk stratify patients who require more frequent monitoring.

Emerging Challenges to the Safe and Effective Use of Methadone for Cancer-Related Pain in Paediatric and Adult Patient Populations

Methadone continues to be an important medication for the treatment of paediatric and adult cancer-related pain. Appropriate patient selection to ensure safe and effective treatment by a team of clinicians who appreciate and are familiar with methadone and its unique pharmacology is crucial. Unlike morphine and other more common opioids, methadone is purported to have involvement with delta-opioid receptor and higher affinity as an N-methyl-D-aspartate-receptor antagonist. Clinically this gives it the advantage of being effective for both nociceptive and neuropathic pain, but also may be useful in the setting of tolerance to other opioids. Methadone also comes in multiple available formulations that can be administrated through a variety of routes beyond the oral route. Challenges with methadone in treating cancer-related pain include drug interactions specifically as it relates to new targeted cancer therapies. Recent guidelines recommend electrocardiogram monitoring with methadone and there is potential for additive cardiac toxicity in the oncology setting. Appropriate dosing of methadone for pain management given age, organ dysfunction, and patients who are on methadone maintenance therapy are also key factors. This article aims to provide clinicians with evidence and clinical practice guidelines for safe and appropriate use of methadone including indication, initiation, and monitoring given its complexity for management of pain in the dynamic oncology setting.

Adult Cancer Pain, Version 3.2019, NCCN Clinical Practice Guidelines in Oncology

In recent years, the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Adult Cancer Pain have undergone substantial revisions focusing on the appropriate and safe prescription of opioid analgesics, optimization of nonopioid analgesics and adjuvant medications, and integration of nonpharmacologic methods of cancer pain management. This selection highlights some of these changes, covering topics on management of adult cancer pain including pharmacologic interventions, nonpharmacologic interventions, and treatment of specific cancer pain syndromes. The complete version of the NCCN Guidelines for Adult Cancer Pain addresses additional aspects of this topic, including pathophysiologic classification of cancer pain syndromes, comprehensive pain assessment, management of pain crisis, ongoing care for cancer pain, pain in cancer survivors, and specialty consultations.

Evaluation of QTc Interval Prolongation Among Patients With Cancer Using Enteral Methadone

CONTEXT:

The effect of methadone on corrected QT interval (QTc) in patients with cancer pain is not well-known.

OBJECTIVES:

To describe and characterize the effect of low-, moderate-, and high-dose enteral methadone on QTc interval in patients with cancer.

METHODS:

Retrospective cohort study including patients prescribed enteral methadone during the 27-month study period. Participants were divided into 3 methadone daily dose groups: <30 (low dose), 30 to 59 (moderate dose), ≥60 (high dose) mg. The primary outcome was the incidence of QTc prolongation (>450 ms for females and >430 ms for males). Secondary outcomes included the magnitude of change in QTc after starting methadone, the incidence of clinically significant QTc prolongation (>500 ms) and the prevalence of torsades de pointes and syncope.

RESULTS:

Two hundred three patients met study inclusion criteria: 91 (45%) low dose, 52 (26%) moderate dose, and 60 (29%) high dose. Incidence of QTc prolongation for low-, moderate-, and high-dose groups was 50 (55%), 37 (71%), and 43 (72%), respectively ( P = .039, low vs high dose). Incidence of clinically significant QTc prolongation was 10 (11%), 4 (8%), and 7 (12%) for low-, moderate-, and high-dose groups. For patients without QTc prolongation prior to initiating methadone, 62% of moderate-dose patients and 67% of high-dose patients had QTc prolongation, while taking methadone.

CONCLUSION:

This study found a notably high incidence of QTc prolongation in patients with cancer using enteral methadone. Future studies should aim to determine the risk of adverse cardiac effects in the cancer population and determine appropriate monitoring of methadone for pain management.

Histopathological study of liver tissue due to methadone consumption and its effect on liver enzymes and inflammatory indices in rat

Background

Methadone (MET)-based treatment is currently one of the best known approaches in the treatment of opioid dependence. It is claimed that MET use exerts adverse effects on the performance of some organs, especially liver. Thus, the present study aims to investigate MET effects on the hepatic tissue as well as its effect on the hepatic enzyme levels and inflammatory markers in rats.

Materials and methods

Twenty-eight mature male Wistar rats underwent an 8-week treatment in four equal groups including the control group (an ordinary daily dietary regime) as well as the experimental groups 1, 2, and 3 (an ordinary daily dietary regime and gavage-fed on MET syrup for 5, 20, and 40 mg/kg body weight per day). Blood samples were collected from all rats in the beginning and end of the study to measure their hepatic enzyme levels and inflammatory markers. In the end, their livers were subjected to histological examinations.

Results

The mean serum levels of hepatic enzymes (alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase) increased considerably across all the three groups that had received various dosages of MET (5, 20, and 40 mg/kg) in the end of the study as compared to the beginning of the study (P<0.001). It was also found that the inflammatory indicators (interleukin-6, tumor necrosis factor-alpha, and C-reactive protein) rose significantly in the groups that had received various dosages of MET in contrast to the control group (P<0.01, P<0.001, and P<0.001, respectively). The histopathological images of the liver cross-sections revealed dosage-dependent tissue changes in the groups that had received various dosages of MET.

Conclusion

The present study tried to prove the adverse effects of MET in the development of liver damage. Since MET-based treatment is frequently prescribed by physicians for curing the addiction to narcotics, better strategies are required for its correct usage.

2017 HIVMA of IDSA Clinical Practice Guideline for the Management of Chronic Pain in Patients Living With HIV

Pain has always been an important part of human immunodeficiency virus (HIV) disease and its experience for patients. In this guideline, we review the types of chronic pain commonly seen among persons living with HIV (PLWH) and review the limited evidence base for treatment of chronic noncancer pain in this population. We also review the management of chronic pain in special populations of PLWH, including persons with substance use and mental health disorders. Finally, a general review of possible pharmacokinetic interactions is included to assist the HIV clinician in the treatment of chronic pain in this population.It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. The Infectious Diseases Society of American considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

Use of Methadone to Reverse Opioid Escalation in a Patient With Surgical Pain

Acute pain is a prevalent issue for patients recovering from surgical procedures. Methadone has been recognized as a unique option for treatment of surgical pain due to its multiple mechanisms of analgesia and its potential to decrease tolerance to other opioids. Studies of methadone use in postoperative settings are sparse in part due to safety concerns, such as complex pharmacokinetics, risk of respiratory depression, and association with arrhythmias. In this case study of a 70-year-old male with postsurgical abdominal pain, methadone utilization over a period of 9 days resulted in patient-reported analgesia and aided in de-escalating overall opioid use. More studies are needed to develop guidance on how methadone can be used to relieve pain following surgical procedures.

Methadone: Maximizing Safety and Efficacy for Pain Control in Patients with Cancer

Methadone is a valuable opioid in the management of patients who have cancer with pain. Methadone is a mu-, kappa-, and delta-opioid agonist, and an N-methyl-D-aspartate receptor antagonist. These mechanisms of action make methadone an attractive option for complex pain syndromes. It is critically important that providers consider a patient's risk status before beginning methadone. Careful consideration must be given to dosing methadone in both opioid-naïve and opioid-tolerant patients, with vigilant monitoring for therapeutic effectiveness and potential toxicity until the patient achieves steady state.

Practical Pharmacology of Methadone: A Long-acting Opioid

Methadone is a naturally long-acting analgesic with unique pharmacodynamic and pharmacokinetic properties compared to other opioids, available now in India, to treat severe pain. It has the potential to dramatically relieve suffering among patients with serious illness who are living with persistent physical pain. However, clinicians must appreciate its unique pharmacologic properties and its use in clinical practice safely and effectively. The available formulation in India is a racemic mixture of the S- and R-enantiomers, and as such, it will have a propensity for drug-drug and drug-genetic interactions that can increase the risk of Torsades de Point and respiratory depression. Appropriate patient selection, careful dosing and thorough monitoring of methadone will mitigate these risks.

Challenges of Using Methadone in the Indian Pain and Palliative Care Practice

Palliative care providers across India lobbied to gain access to methadone for pain relief and this has finally been achieved. Palliative care activists will count on the numerous strengths for introducing methadone in India, including the various national and state government initiatives that have been introduced recognizing the importance of palliative care as a specialty in addition to improving opioid accessibility and training. Adding to the support are the Non-Governmental Organizations (NGOs), the medical fraternity and the international interactive and innovative programs such as the Project Extension for Community Health Outcome. As compelling as the need for methadone is, many challenges await. This article outlines the challenges of procuring methadone and also discusses the challenges specific to methadone. Balancing the availability and diversion in a setting of opioid phobia, implementing the amended laws to improve availability and accessibility in a country with diverse health-care practices are the major challenges in implementing methadone for relief of pain. The unique pharmacology of the drug requires meticulous patient selection, vigilant monitoring, and excellent communication and collaboration with a multidisciplinary team and caregivers. The psychological acceptance of the patient, the professional training of the team and the place where care is provided are also challenges which need to be overcome. These challenges could well be the catalyst for a more diligent and vigilant approach to opioid prescribing practices. Start low, go slow could well be the way forward with caregiver education to prescribe methadone safely in the Indian palliative care setting.

The frequency of QTc prolongation among pediatric and young adult patients receiving methadone for cancer pain

INTRODUCTION

A prolonged corrected QT (QTc) interval in pediatric patients is defined as ≥470 msec. Methadone can cause a prolonged QTc interval that can lead to ventricular arrhythmias. The risk of methadone-induced prolongation of the QTc interval in children and young adults is unknown. The purpose of the study was to determine the frequency of QTc prolongation among pediatric and young adult patients with cancer pain on methadone treatment.

METHODS

We retrospectively reviewed data for all patients on methadone during the study period. Qualifying patient data were reviewed to determine whether these patients had an electrocardiogram (ECG) while on methadone. The QTc values for analysis were manually calculated using the standard formula described by Bazett.

RESULTS

Twenty-five patients were identified that met eligibility criteria. The median QTc decreased from baseline after initiation of methadone. QTc prolongation occurred in four of 25 (16%) patients and only one patient had a QTc greater than 500 msec. This patient had 17 normal QTc intervals on methadone prior to the prolongation. After resolution of electrolyte abnormalities, six subsequent ECGs on methadone had a normal QTc interval.

CONCLUSIONS

Prolongation of the QTc interval is infrequent. The only observed case was transient during multiple comorbid conditions. A prospective study is justified to better understand what role methadone plays as one of many risk factors for prolongation of the QTc interval in children and young adults.

Cardiovascular effects of methadone and concomitant use of diazepam during methadone maintenance treatment induction: low concentration risk

BACKGROUND

The aim is to evaluate the role of diazepam concentrations in development of low-concentration-methadone-associated QTc prolongation in patients with opioid use disorder during methadone maintenance treatment (MMT) induction.

RESEARCH DESIGN AND METHODS

Individuals with addiction disorder on MMT were studied before the beginning of MMT and after one and six months of MMT. Serum concentrations of methadone, diazepam, electrolytes and ECG were analyzed.

RESULTS

Thirty patients were enrolled. The mean methadone concentration at time points was 177 ± 119 ng/ml and 343 ± 182 ng/ml, while the mean diazepam concentration was 561 ± 437 ng/ml and 1045 ± 933 ng/ml. The QTc interval before the introduction of MMT, after 1 and 6 months of MMT were 412 ± 27 ms, 425 ± 18 ms and 424 ± 15 ms, respectively, showing statistically significant increase in the length of QTc interval after 1 and 6 months of MMT. Statistically significant correlation between the concentration of methadone and QTc interval length at observed time points (R² = 0.239, p = 0.018; R² = 0.513, p = 0.006) was shown, and it remained so if the concentration of diazepam was included (R² = 0.347, p = 0.026, R² = 0.513, p = 0.009).

CONCLUSIONS

The prolongation of QTc below the risk threshold in low methadone therapeutic doses has been recorded and concomitant use of diazepam could be a co-factor in such issue.

Methadone and Corrected QT Prolongation in Pain and Palliative Care Patients: A Case-Control Study

BACKGROUND

Methadone (ME) is commonly used in pain and palliative care (PPC) patients with refractory pain or intolerable opioid adverse effects (AEs). A unique ME AE is its corrected QT (QTc) interval prolongation risk, but most evidence exists in methadone maintenance therapy patients.

OBJECTIVE

Our goal was to identify QTc interval prolongation risk factors in PPC patients receiving ME and other medications known to prolong the QTc interval and develop a risk stratification tool.

DESIGN

We performed a case-control study of adult inpatients receiving ME for pain management. Settings/Subjects: Adult inpatients receiving ME with a QTc >470 msec (males) and >480 msec (females) were matched 1:2 according to age, history of QTc prolongation, and gender with ME patients who did not have a prolonged QTc interval. QTc prolongation risk factors were collected for both groups. Covariates were analyzed using conditional logistic regression. Classification and regression tree analysis was used to identify the ME dose associated with QTc prolongation.

RESULTS

Predictors of QTc prolongation included congestive heart failure (CHF) (OR: 11.9; 95% CI: 3.7-38.2; p < 0.00), peptic ulcer disease (PUD) (odds ratio [OR]: 8.3; 95% confidence interval [95% CI]: 2.4-28.9; p < 0.00), hypokalemia (OR: 6.5; 95% CI: 1.5-28.2; p < 0.01), rheumatologic diseases (OR: 4.7; 95% CI: 1.6-13.9; p < 0.00), taking medications with a known torsades de pointes (TdP) risk (OR: 4.4; 95% CI: 1.8-10.7; p < 0.01), malignancy (OR: 3.3; 95% CI: 1.2-9.3; p < 0.03), hypocalcemia (OR: 2.1; 95% CI: 0.9-4.8; p < 0.07), and ME doses >45 mg per day (OR: 1.9; 95% CI: 0.8-4.8; p < 0.16). Mild liver disease was protective against QTc prolongation (OR: 0.05; 95% CI: 0.0-0.46; p < 0.01).

CONCLUSIONS

Predictors of QTc prolongation in our multivariate conditional logistic regression model included CHF, PUD, hypokalemia, rheumatologic disorders, use of medications with a known TdP risk, malignancy, hypocalcemia, and ME doses >45 mg per day.

Overall Survival among Cancer Patients Undergoing Opioid Rotation to Methadone Compared to Other Opioids

BACKGROUND

Methadone has been associated with lower overall survival (OS) in patients with chronic pain. There are no data available on the association of methadone with OS in cancer patients.

OBJECTIVE

Our aim was to compare the OS in cancer outpatients undergoing opioid rotation (OR) to methadone and other strong opioids.

DESIGN

Demographics, symptoms, and morphine equivalent daily dose (MEDD) were collected in patients who underwent OR from strong opioids to either methadone or other strong opioids and returned for a follow-up within six weeks.

SETTING/SUBJECTS

Nine hundred thirty-eight consecutive outpatients to the supportive care center of a tertiary cancer center were reviewed.

MEASUREMENTS

Kaplan-Meier curves were used to evaluate survival.

RESULTS

Of a total of 164 eligible patients, 54/76 patients who underwent OR to methadone and 48/88 patients who underwent OR to other opioids returned for a follow-up visit. The median age was 56 years, 54% were male, and 87% had advanced cancer. There were no significant differences between the two groups in patient characteristics, performance status, MEDD, and pain scores. The Kaplan-Meier curves revealed no significant difference in median OS between all patients undergoing OR to methadone and other opioids [3.75 months (95% confidence interval, CI, 2.30-6.46) vs. 2.62 months (95% CI 1.74-4.33); p = 0.35] and also among those who returned for a follow-up following an OR to methadone and other opioids [5.15 months (95% CI 3.64-7.41) vs. 5.90 months (95% CI 2.62-9.28); p = 0.89].

CONCLUSIONS

We observed no significant difference in OS in cancer patients in methadone group compared to other opioids.

Methadone prolongs cardiac conduction in young patients with cancer-related pain

OBJECTIVE

Methadone prolongs cardiac conduction, from mild corrected QT (QTc) prolongation to torsades de pointes and ventricular fibrillation, in adults. However, methadone use for pain and its effects on cardiac conduction have not been investigated in pediatric populations.

METHODS

A retrospective review of QTc intervals in patients receiving methadone analgesia was conducted. Medical records from a 4-year period (September 2006 to October 2010) at a pediatric oncology institution were reviewed, and correlations were tested between cardiac conduction and methadone dosage and duration of therapy, electrolyte levels, renal and hepatic dysfunction, and concurrent medications.

RESULTS

Of the 61 patients who received methadone, 37 met our inclusion criteria and underwent 137 electrocardiograms (ECGs). During methadone treatment, the mean QTc was longer than that at baseline (446.5 vs 437.55 ms). The mean methadone dose was 27.0±24.3 mg/d (range, 5-125 mg/d; median, 20 mg/d) or 0.47±0.45 mg/kg per day (range, 0.05-2.25 mg/kg per day; median, 0.37 mg/kg per day), and the mean duration of therapy was 49 days. The authors identified a correlation between automated and manual ECG readings by two cardiologists (Pearson r=0.649; p<0.0001), but the authors found no correlations between methadone dose or duration and concurrent QTc-prolonging medications, sex, age, electrolyte abnormalities, or renal or hepatic dysfunction.

CONCLUSION

At a clinically effective analgesic dose, methadone dosage and duration were not correlated with QTc prolongation, even in the presence of other risk factors, suggesting that methadone use may be safe in pediatric populations. The correlation between automated and manual ECG readings suggests that automated ECG readings are reliable for monitoring cardiac conductivity during the reported methadone-dosage regimens.

The Impact of Opioids on Cardiac Electrophysiology

Synthetic opioid agents have been used in modern medicine for over a century and for opioid addiction treatment for over a half-century. Liberal use of opioids in the United States has been attended by an extraordinary increase in opioid-related mortality, with over 16,000 deaths in 2012. As there have been advances in opioid agents for pain and addiction, so have there been advances in our understanding of the cardiac effects of these agents. In the last 10 years, significant data regarding electrophysiologic effects of these agents have been collected. We aim in this review to discuss the effects on cardiac electrophysiology of the various opioid agents currently in use and the evidence that these effects are contributing to the rise in opioid-related mortality.

Chronic opioid therapy in long-term cancer survivors

PURPOSE

Long-term cancer survivors develop special health issues and specific needs. Chronic pain, whether the consequence of their cancer or as a side effect of treatment, is one of their most prevalent concerns.

METHODS

We conducted a review of the English-language literature on long-term cancer survivorship and chronic opioid therapy, with the objective of determining the efficacy, safety and tolerability in this group of patients. Practical management recommendations are made on the basis of this review.

RESULTS

Pain syndromes encountered in the long-term cancer survivors are diverse. Opioid receptor pathways possess complex and pleiotropic functions and continuous over-activation may lead to de novo endocrinopathies, immunosuppression, neurocognitive impairment, or cell cycle disturbances with potential clinical connotations. However, there are insufficient data to support evidence-based decision making with respect to patient selection, doses, administration, monitoring and follow-up. Data about long-term treatment effectiveness and safety are limited and often aggravated by the overlapping of several diseases prevalent among long-term cancer survivors, as well as chronic opiate-induced toxicity.

CONCLUSIONS

Chronic opioid therapy is frequent in long-term cancer survivors, and may negatively affect the immune system, and produce health problems such as endocrinopathies, osteoporosis, neurological or cardiopulmonary effects, alterations of cell cycle kinetics, abuse and addiction. This review highlights the need for specialized teams to treat chronic pain in long-term cancer survivors from an integrative perspective.

Efficacy and Safety of Methadone as a Second-Line Opioid for Cancer Pain in an Outpatient Clinic: A Prospective Open-Label Study

INTRODUCTION

Most clinical reports on methadone rotation describe outcomes in hospitalized patients. The few studies that have included outpatients are retrospective. The aim of this study was to assess the efficacy and safety of methadone as a second-line opioid in adult patients with advanced cancer after rotation in routine clinical practice at a palliative care outpatient clinic.

PATIENTS AND METHODS

This was a prospective, open-label study of 145 patients whose treatment was rotated from other opioids to methadone. Informed consent was obtained in all cases. The main outcome measure was change in the variable "worst pain" at day 28. Pain and pain interference were assessed with the Brief Pain Inventory, with side effects evaluated according to the Common Terminology Criteria for Adverse Events version 3.0. Pain levels were evaluated at study entry and at days 3, 7, 9, 14, 21, and 28.

RESULTS

Rotation to methadone was performed for the following reasons: poor pain control (77.9%), opioid side effects (2.1%), or both (20%). The mean daily oral morphine equivalent dose before rotation was 193.7 mg. The median worst and average pain scores decreased significantly (p < .0001) from baseline to day 28: The median worst pain score decreased from 9 (interquartile range [IQR]: 8-10) to 6 (IQR: 3-8), and the median average pain score decreased from 6 (IQR: 5-7) to 4 (IQR: 2-5). The proportions of patients with moderate to severe worst and average pain decreased by 30.3% and 47.5%, respectively, by day 28. No increase in opioid toxicity was observed during the study.

CONCLUSION

In outpatients with advanced cancer, rotation to methadone as a second-line opioid was efficacious and safe when using a tiered scheme with close follow-up by experienced health professionals.

IMPLICATIONS FOR PRACTICE

The results of this study, conducted prospectively under real clinical conditions, support the efficacy and safety of oral methadone as a second-line opioid in ambulatory patients with cancer. Moreover, these findings corroborate previously reported outcomes in retrospective outpatient studies and prospective studies that evaluated inpatient populations. Although more research into methadone rotation strategies is still needed, this study describes a successful tiered scheme of oral methadone rotation that was proven safe and effective during follow-up.

The QTc effect of low-dose methadone for chronic pain: a prospective pilot study

OBJECTIVE

Methadone is associated with QT prolongation and serious cardiac complications, but this has been primarily demonstrated in opioid dependent patients receiving moderate to high doses. This study investigates the effect of low-dose methadone on the QTc interval in a chronic pain population.

DESIGN AND SUBJECTS

We conducted a prospective cohort study in a chronic pain clinic including 82 patients receiving methadone and 102 patients receiving non-methadone opioid therapy.

METHODS

We analyzed automated QTc calculations from 12-lead electrocardiograms at baseline and during the subsequent 6 months. The primary outcome of interest was the incidence of QTc greater than 470 milliseconds or an increase from baseline of greater than 60 milliseconds.

RESULTS

The methadone group did not manifest an overall higher frequency of QTc > 470 milliseconds (6% for the methadone group vs 5% for controls, P = 0.722) or an increase in the QTc of > 60 milliseconds (4% for the methadone group vs 4% for controls, P = 0.94). In the first month after initiating methadone, patients demonstrated an increase in QTc compared to controls (5% for the methadone group vs 0% for the controls, P = 0.073) but the difference disappeared in the third and sixth months.

CONCLUSION

Data from our chronic pain clinic support a potential association of QTc prolongation during the initiation of methadone, but this effect is small and short lived. We believe larger scale studies to further characterize the safety profile of low-dose methadone are warranted.

Evaluation of Methadone-Induced QTc Prolongation in a Veteran Population

Understanding the effects of methadone on the QTc interval in a veteran patient population using the drug at lower doses for pain may help clinicians develop strategies and protocols for safe use.

Research gaps on methadone harms and comparative harms: findings from a review of the evidence for an American Pain Society and College on Problems of Drug Dependence clinical practice guideline

Methadone-associated overdose deaths have dramatically increased. In order to inform an evidence-based clinical practice guideline to improve safety of methadone prescribing, the American Pain Society commissioned a systematic review on various aspects related to methadone safety. We searched Ovid MEDLINE, Cochrane Library, and PsycINFO databases through July 2012 to identify studies that addressed 1 or more of 17 Key Questions related to methadone safety; an update search was performed in 2014 for new studies related to methadone-related overdose and risks related to cardiac arrhythmias. A total of 168 studies met inclusion criteria for the review. The purpose of this article is to highlight critical research gaps in the literature related to methadone safety. These include lack of evidence on risk factors associated with methadone-overdose deaths and adverse events, limited evidence to evaluate the comparative mortality of methadone versus other opioids, insufficient evidence to fully understand the harms associated with methadone use during pregnancy, and insufficient evidence to determine effects of risk mitigation strategies such as electrocardiogram monitoring, strategies for managing patients with prolonged QTc intervals on screening, urine drug testing, alternative dosing regimens for initiation and titration of therapy, and timing of follow-up. Therefore, most guideline recommendations are based on weak evidence. More research is needed to guide safe methadone prescribing practices and decrease the adverse events associated with methadone.

PERSPECTIVE

This article summarizes critical research gaps in the literature related to methadone safety, based on a systematic review commissioned by the American Pain Society. Critical research gaps were identified in a number of areas, highlighting the need for additional research to guide safer prescribing and risk mitigation strategies.

Methadone overdose and cardiac arrhythmia potential: findings from a review of the evidence for an American Pain Society and College on Problems of Drug Dependence clinical practice guideline

The number of deaths associated with methadone use increased dramatically in parallel with marked increases in its use, particularly for treatment of chronic pain. To develop a clinical guideline on methadone prescribing to reduce potential harms, the American Pain Society commissioned a review of various aspects related to methadone safety. This article summarizes evidence related to unintentional overdose due to methadone and harms related to cardiac arrhythmia potential. We searched Ovid MEDLINE, the Cochrane Library, and PsycINFO databases through January 2014 for studies assessing harms associated with methadone use; we judged 70 studies to be relevant and to meet inclusion criteria. The majority of studies on overdose and cardiac arrhythmia risk are observational and provide weak evidence on which to base clinical guidelines. In patients prescribed methadone for treatment of opioid dependence, data suggest that mortality benefits related to reduction in illicit drug use outweigh harms. Despite epidemiologic data showing marked increases in the numbers of methadone-related deaths that have been primarily attributed to increased use of methadone for chronic pain, evidence on methadone and mortality risk in this population has been somewhat contradictory. There is some evidence that recent initiation of methadone, psychiatric admissions, and concomitant use of benzodiazepines are associated with a higher risk for overdose. Evidence on cardiac risks is primarily limited to case reports of torsades de pointes, primarily in patients on high doses of methadone, and to studies showing an association between methadone use and prolongation of QTc intervals. Research is needed to understand the effectiveness of dosing methods, electrocardiogram monitoring, and other risk mitigation strategies in patients prescribed methadone.

PERSPECTIVE

This systematic review synthesizes the evidence related to methadone use and risk for overdose and cardiac arrhythmia. Findings regarding the association between methadone use and QTc interval prolongation and risk factors for methadone-associated overdose suggest potential targets for risk mitigation strategies, though research is needed to determine the effectiveness of such strategies at reducing adverse outcomes.

Methadone for pain and the risk of adverse cardiac outcomes

CONTEXT

There are few studies that describe cardiac adverse events in patients prescribed methadone for pain management.

OBJECTIVES

To describe incident cardiac adverse events and risk factors for cardiac adverse events in primary care patients prescribed methadone for pain.

METHODS

This was a retrospective, descriptive, cohort study in patients 18 years or older receiving methadone for pain management during 2010. Patients were followed for 12 months and were categorized as "chronic" or "non-chronic" methadone users. The primary outcomes were a cardiac event, at risk for an event, or neither. Patients were grouped on their outcome and were compared on risk factors and methadone monitoring.

RESULTS

A total of 1246 patients were included. Thirty (2.4%), 628 (50.4%), and 588 (47.2%) patients had a cardiac event, were at risk for an event, or had neither an event nor a risk factor, respectively. Overall, the rate of QTc prolongation was 49.4% and the rate of adherence to recommended cardiac monitoring was 39.0%. Similar percentages of chronic and non-chronic users had a cardiac event (P > 0.05). Among the patients who had a cardiac event and were at risk for an event, factors independently associated with having had an event included age (odds ratio = 1.06; 95% CI = 1.03-1.09) and a dose 100 mg/day or higher (odds ratio = 6.18; 95% CI = 1.08-35.45).

CONCLUSION

Few cardiac adverse events resulting from methadone use for pain were detected. However, a large proportion of patients were at risk for an adverse event, especially patients who were older and had received ≥ 100 mg/day of methadone.

[Use of methadone in the elderly with cancer pain: a systematic review]

OBJECTIVE

To identify the clinical use of methadone as an analgesic in the management of cancer pain in elderly patients.

MATERIAL AND METHODS

We performed a systemic review of the literature on the specific use of methadone in elderly with cancer pain in MEDLINE, COCHRANE DATABASE and SCOPUS. A second search was conducted in MEDLINE to look for clinical trials and systematic review of the use of methadone in cancer pain, selecting only those in which the mean age of patients was ≥ 65 years old.

RESULTS

Four articles were obtained in the first search, and from the second 7 clinical trials, none of them specific to methadone use in elderly patients with cancer.

CONCLUSIONS

There are insufficient data on the use of methadone as an analgesic in the elderly with cancer. Given its pharmacological characteristics it must be used by trained personnel. Several recommendations are proposed for its use as an analgesic in the treatment of cancer pain in the elderly.

Effects of disulfiram on QTc interval in non-opioid-dependent and methadone-treated cocaine-dependent patients

OBJECTIVES

Methadone and cocaine are each known to prolong the QTc interval, a risk factor for developing potentially fatal cardiac arrhythmias. Disulfiram, often administered in the context of methadone maintenance to facilitate alcohol abstinence, has been shown to have some efficacy for cocaine dependence. Disulfiram has differential effects on cocaine and methadone metabolism, but its impact on methadone- or cocaine-induced changes in QTc interval is unclear. Thus, the effects of disulfiram on QTc interval in a subset of cocaine-dependent patients participating in a 14-week, randomized, double-blind, placebo-controlled clinical trial of disulfiram were prospectively determined.

METHODS

Opioid-dependent participants were inducted onto methadone (weeks 1-2; MT) and both MT and non-opioid-dependent (UT) participants were randomized to receive disulfiram (weeks 3-14) at one of the following doses: 0, 250, 375, or 500 mg/d. Electrocardio-grams were obtained before study entry and during weeks 2 and 4.

RESULTS

Complete QTc-interval data in 23 MT and 18 UT participants were analyzed. QTc interval tended to be higher in MT participants relative to UT participants, regardless of disulfiram dose and time point, but disulfiram did not differentially alter QTc interval. QTc interval was, however, significantly greater in participants with recent cocaine use than in those with no recent use.

CONCLUSIONS

These results suggest that cocaine use and possibly MT status, but not disulfiram, are risk factors for QTc prolongation.

Palliative care research: lessons learned by our team over the last 25 years

BACKGROUND

In the last 25 years, palliative care has made major progress as an interdisciplinary specialty that addresses quality-of-life issues for patients with life-limiting illnesses and their families. Research by numerous investigators has contributed to our increasing body of knowledge to support an evidence-based practice.

AIM

We highlight some lessons learned by our group in the process of conducting palliative care research, focusing in particular on symptom assessment; the management of pain, fatigue, cachexia, dyspnea, delirium, and opioid-induced neurotoxicity; and outcomes of our palliative care program.

DESIGN

Narrative review of selected literature, focusing on studies conducted by our group.

DATA SOURCES

This article is based on the Second Vittorio Ventafridda Memorial Lecture by Dr Eduardo Bruera, delivered at the European Association for Palliative Care, Trondheim, Norway on 8 June 2012.

RESULTS

For each topic, we review some of the pivotal studies in palliative care, discuss the challenges in research design, and outline possible directions for future research.

CONCLUSIONS

We conclude by sharing some of what we learned about the processes, pearls, and pitfalls of palliative care research.

Methadone rotation for cancer patients with refractory pain in a palliative care unit: an observational study

BACKGROUND

Methadone has been reported to be as effective as morphine for cancer pain management. It is commonly used as an alternative opioid in case of insufficient relief.

OBJECTIVE

Our aim was to assess efficacy and tolerance of opioid rotation to methadone for refractory cancer pain management in palliative care unit (PCU) inpatients.

METHODS

All the patients undergoing opioid rotation to methadone from 2008 to 2011 in two PCUs (Lyon and Nice, France) were included. Pain assessments were undertaken on day 0 (D0), day 3 (D3), day 7 (D7), and day 14 (D14) using a visual analogue scale (VAS; 0-10) and the Douleur Neuropathique 4 (DN4) scale for neuropathic pain. Patients reported pain relief using a 4-point Likert scale (1=no relief; 4=important relief ).

RESULTS

Nineteen patients (7 females) with a median age of 55 (Q1-Q3; 44-58) underwent methadone rotation. The most common type of cancer was gastrointestinal. Seventeen patients had a diagnosis of mixed pain syndromes. Morphine equivalent daily dose (MEDD) prior to switching was 480 mg (Q1-Q3; 100-1021), and at least two nonmethadone opioid rotations had already been done for 13 patients. Between D0 and D7, the VAS score decreased by 4 points (p<0.001). The DN4 score became negative on D7 for 11 of 17 patients (65%). On D7, 16 of 18 patients (89%) expressed moderate to greater than moderate pain relief. Methadone was discontinued in one patient on D7 because it was deemed ineffective and for 8 patients, who were unable to take oral drugs, it was discontinued after D14.

CONCLUSION

Our results suggest that methadone is effective and well tolerated for refractory cancer pain.

Functional genetic polymorphisms in CYP2C19 gene in relation to cardiac side effects and treatment dose in a methadone maintenance cohort

Abstract Methadone maintenance therapy is an established treatment for heroin dependence. This study tested the influence of functional genetic polymorphisms in CYP2C19 gene encoding a CYP450 enzyme that contributes to methadone metabolism on treatment dose, plasma concentration, and side effects of methadone. Two single nucleotide polymorphisms (SNPs), rs4986893 (exon 4) and rs4244285 (exon 5), were selected and genotyped in 366 patients receiving methadone maintenance therapy in Taiwan. The steady-state plasma concentrations of both methadone and its EDDP metabolite enantiomers were measured. SNP rs4244285 allele was significantly associated with the corrected QT interval (QTc) change in the electrocardiogram (p=0.021), and the Treatment Emergent Symptom Scale (TESS) total score (p=0.021) in patients who continued using heroin, as demonstrated with a positive urine opiate test. Using the gene dose (GD) models where the CYP2C19 SNPs were clustered into poor (0 GD) versus intermediate (1 GD) and extensive (2 GD) metabolizers, we found that the extensive metabolizers required a higher dose of methadone (p=0.035), and showed a lower plasma R-methadone/methadone dose ratio (p=0.007) in urine opiate test negative patients, as well as a greater QTc change (p=0.008) and higher total scores of TESS (p=0.018) in urine opiate test positive patients, than poor metabolizers. These results in a large study sample from Taiwan suggest that the gene dose of CYP2C19 may potentially serve as an indicator for the plasma R-methadone/methadone dose ratio and cardiac side effect in patients receiving methadone maintenance therapy. Further studies of pharmacogenetic variation in methadone pharmacokinetics and pharmacodynamics are warranted in different world populations.