Prevalence and Predictors of Early Response to Adjunct Methadone for Cancer-Related Pain in Palliative Care Patients—A Retrospective Study

Abstract

Background:

Adjunct methadone has been used previously for cancer-related pain, but evidence on predictors for early response remains limited.

Objective:

Identify the prevalence and predictors of early adjunct methadone response in palliative care patients.

Design:

Retrospective cohort study.

Settings/Subjects:

Patients who initiated adjunct methadone from 2022 to 2024.

Measurement:

Univariate and multivariate Poisson regression identified prevalence and predictors of early response.

Results:

Among 42 patients, 28 (67%) achieved early response. They had higher baseline oral morphine equivalents, higher starting methadone doses, and shorter days to first titration (p < 0.05). Predictors included metastatic cancer (RR 3.30, p = 0.005), higher performance status (RR 2.58, p = 0.033), methadone daily dose >5 mg (RR 3.91, p = 0.013), lower baseline pain scores (RR 0.78, p = 0.025), and preserved liver function (RR 4.32, p = 0.009).

Conclusion:

Metastatic cancer patients with high performance status without liver damage may benefit from a higher, proactively titrated starting dose of adjunct methadone.