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

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.