Forty per cent of cancer pain associate neuropathic and nociceptive pain simultaneously, and refractory pain affects 15% of cancer pain. Methadone is an effective opioid in treating nociceptive pain and could have an effect on neuropathic pain. Uncertainty remains on its effects on the different subcomponents of neuropathic pain.
Objectives To identify which subcomponents of neuropathic cancer pain are addressed using methadone.
Methods An observational prospective cohort study of palliative care inpatients after rotation for refractory neuropathic cancer pain. Pain intensity was assessed weekly for 28 days, using a Visual Analogue Scale (VAS) and the Neuropathic Pain Symptom Inventory (NPSI).
Results Forty-eight patients were included and 17 completed the 28 days follow-up. VAS pain rating decreased by at least 20 mm in 47% of patients and the pain intensity was significantly lower at day 28 with 53% of patients with a VAS inferior to 4 (p<0.001). The pressure/squeezing component (NPSI score) decreased by more than 2 points in 50% of patients.
A linear regression showed allodynia and pressure/squeezing were responsible for the largest part of the overall alleviation of pain (p=0.01).
Conclusions Methadone could significantly improve neuropathic pain through a targeted effect of allodynia and its pressure/squeezing component.
Statistics from Altmetric.com
Contributors AF: Had the original idea, developed the project, developed the statistical analysis plan, and wrote the manuscript. EP-C: Leaded the clinical team for recruitment and patient follow-up,reviewed and approved the final manuscript. MR: Handeled the database creation and maintenance and the data management, reviewed and approved the final manuscript. MF: Wrote the study protocol, had a significant impact on the analyses, reviewed and approved the final manuscript. CT: Performed a large amount of patient recruitment and clinical follow-up, reviewed the protocol, reviewed and approved the final manuscript. GE: Headed the steering committee, had a significant impact on the article redaction and approved its final version.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.