Clinical Outcomes of Methadone for Refractory Cancer Pain, Including Add-On Switching to Prior Opioids

Area of Science:

• Oncology
• Pain Management
• Pharmacology

Background:

• Methadone is recognized for treating refractory cancer pain.
• Japanese guidelines suggest methadone for strong opioid-refractory cancer pain.
• Optimal methadone-switching strategies require further clarification.

Purpose of the Study:

• To evaluate methadone switching methods for refractory cancer pain.
• To compare the efficacy and safety of the stop-and-go (SAG) versus add-on methadone methods.
• To assess pain reduction and adverse events associated with different methadone strategies.

Main Methods:

• Retrospective analysis of 34 patients with refractory cancer pain treated with methadone.
• Evaluation of methadone switching methods, including SAG and add-on approaches.
• Assessment of Numerical Rating Scale (NRS) scores and adverse events.

Main Results:

• The add-on method was used in 81.2% of cases, compared to 18.7% for SAG.
• Pain reduction (NRS scores) was observed in 93.7% of patients (66.6% SAG, 100% add-on).
• The add-on method showed fewer adverse events and facilitated continued opioid use.

Conclusions:

• Methadone is effective for refractory cancer pain, with the add-on method demonstrating favorable safety and efficacy.
• The add-on method offers flexibility by allowing the continuation of prior opioid regimens.
• The add-on strategy may be a preferred clinical approach for methadone initiation in cancer pain management.