Differences in the Analgesic Effect of Opioids on Pain in Cancer Patients With Spinal Metastases

Methadone to treat chemotherapy-induced peripheral neuropathy (METACIN): study protocol

RATIONALE

Chronic chemotherapy-induced peripheral neuropathy (CIPN) affects 70% of cancer patients, causing neuropathic pain. Duloxetine is the most recommended treatment for CIPN per most guidelines. However, Methadone, an alternative and effective treatment for refractory neuropathic cancer pain has been under-recognized and under-studied in patients with CIPN.

PARTICIPANTS

Adult patients with cancer and life expectancy greater than 12 weeks who have >grade 1 CIPN based on National Cancer Institute Common Toxicity Criteria for Adverse Events version 5.0 grading scale lasting ≥3 months beyond chemotherapy completion.

INTERVENTION

A triple-blind, double-dummy randomized controlled trial, participants randomized to either methadone or duloxetine, followed weekly over 5 weeks with dose titration.

OUTCOMES

Primary outcome is the efficacy of methadone versus duloxetine in reducing average pain intensity from baseline to study end. Secondary outcomes include improvements in functional and quality-of-life interference. Exploratory outcomes include proportion of participants achieving ≥30% or ≥50% pain reduction, patient-reported global impression of change, incidence of adverse events, and methadone dose escalation over a 24-week follow up period.

ANTICIPATED IMPACT

This study will determine if methadone is a viable treatment for CIPN; a very common, distressing, and debilitating condition that otherwise has limited treatment options.

CLINICAL TRIAL REGISTRATION

www.clinicaltrials.gov identifier is NCT05786599.

Research Progress of Hydromorphone in Clinical Application

A common opioid analgesic for cancer pain and, to a lesser extent, non-cancer pain, is hydromorphone (HM). Oral formulations as well as subcutaneous, intravenous, and other routes are frequently used for its administration. Its pharmacokinetics and pharmacodynamics have also been extensively researched. This article examines the pharmacological properties of hydromorphone and the development of its use both domestically and internationally with the goal of serving as a reference for the sensible clinical use of this medication. Key words Hydromorphone, Pharmacological action, Route of administration, Cancer pain, Adverse effects.

Methadone in Cancer-Related Neuropathic Pain: A Narrative Review

Background and Objective: Cancer-related neuropathic pain (CRNP) is often a significant burden on patients' quality of life. There are limited treatment guidelines for cancer-related neuropathic pain outside of CIPN. Although opioids are considered a third-line treatment option, no consensus exists on which opioid is most effective, either as a single agent or in combination with other medications. Our aim is to review and update the literature for methadone use in CRNP, since the last review was conducted in 2006. Methods: A comprehensive literature search was performed to evaluate the use of methadone in cancer-related neuropathic pain. Articles were identified from PubMed, Google Scholar, and Cochrane Library using the following keywords: "methadone AND cancer pain AND neuropathic pain" and "cancer-related opioid treatment". Results: Studies were included if they evaluated methadone's efficacy or safety in neuropathic pain management for patients with cancer. This review focused on randomized controlled trials (RCTs), systematic reviews, meta-analyses, and observational studies published between 2000 and 2024. Studies were excluded if they lacked specific data on cancer-related neuropathic pain or were case reports. Conclusions: The unique mechanisms of action and preliminary clinical trials support methadone's status as the first opioid to consider for CRNP when non-opioid first-line treatments have failed to alleviate patient symptoms. Methadone can also be considered as a first-line opioid in patients with mixed nociceptive-neuropathic pain and any of the following features: renal dysfunction; administration of opioids through a feeding tube; a lack of financial resources/insurance; and a switch from another high-dose opioid. More research is needed regarding methadone for CRNP and methadone's preferential use in specific sub-groups of patients.

Tapentadol: A Comprehensive Review of Its Role in Pain Management

Pain is a prevalent issue among patients, requiring effective management to prevent the transition of acute pain into chronic pain and to mitigate significant clinical and socioeconomic impacts, such as increased morbidity, mortality, prolonged recovery, unplanned readmissions, and diminished quality of life. Despite advancements in pain management guidelines, achieving consistent pain relief remains challenging due to individual differences in pain thresholds, the nature of surgical procedures, patient age, and existing comorbidities. Tapentadol, an opioid that acts as both a μ-opioid receptor agonist and a noradrenaline reuptake inhibitor, presents a promising option for pain management. Approved by the FDA in 2008 for immediate release and in 2011 for extended release, tapentadol effectively addresses both nociceptive and neuropathic pain, offering a more favorable efficacy-safety profile compared to traditional opioids such as tramadol. Additionally, tapentadol is gaining recognition as a preferred option for managing significant pain in cancer patients due to its effectiveness and reduced side effects. This review evaluates tapentadol's clinical and pharmacological attributes, systematically analyzing literature on its efficacy, safety, pharmacokinetics, and comparative effectiveness, suggesting that tapentadol is a viable option for effective pain management with potential for broader clinical applications.

Shifting Views on Cancer Pain Management: A Systematic Review and Network Meta-Analysis

CONTEXT

Strong opioids are the cornerstone in the treatment of cancer-related pain.

OBJECTIVES

This study aims to compare analgesic effectiveness of different strong opioids for the treatment of cancer-related pain.

METHODS

PubMed and Embase were searched for RCTs that compared strong opioids for treatment of cancer-related pain against one another. A network meta-analysis was conducted and the related Surface Under the Cumulative RAnking (SUCRA)-based treatment ranks were calculated. Primary outcome was pain intensity (numerical rating scale (NRS)) and/or the percentage of patients with ≥50% pain reduction, after 1 and 2-4 weeks.

RESULTS

Sixteen RCTs (1813 patients) were included. Methadone showed, with a high certainty of evidence, increased ORs for treatment success at 1 week, compared with morphine, buprenorphine, fentanyl, and oxycodone, range 3.230-36.833. Methadone had the highest likelihood to be the treatment of preference (ToP) (SUCRA 0.9720). For fentanyl, ORs were lower, however significant and with high certainty. After 2-4 weeks, methadone again showed the highest likelihood for ToP, however, with moderate certainty and nonsignificant ORs. The combination of morphine/methadone, compared with morphine, buprenorphine, fentanyl, hydromorphone, methadone, and oxycodone achieved a treatment effect of mean NRS difference after 2-4 weeks between -1.100 and -1.528 and had the highest likelihood for ToP.

CONCLUSION

The results suggest that methadone possibly deserves further promotion as first-line treatment for the treatment of cancer-related pain.