A Retrospective Study of the Efficacy and Safety of Three Methadone Initiation Strategies for Refractory Cancer Pain: Stop-and-go, Partial Switching, and Add-on Methods

Abstract

Objective: Methadone is used for the management of refractory cancer pain, and several initiation strategies have been reported: the stop-and-go (SG), partial switching (PS), and add-on (AO). This study aimed to explore the efficacy and safety of three methadone initiation strategies. Methods: This retrospective study included patients who were prescribed methadone at our hospital between January 2018 and December 2021. SG was defined as discontinuation of the preceding opioid before methadone initiation, PS as replacement of part of the opioid dose with methadone, and AO as addition of methadone to the existing opioid regimen. The efficacy and safety of methadone were evaluated in the SG, PS, and AO groups. Results: A total of 64 cases were included: 15 in the SG group, 23 in the PS group, and 26 in the AO group. The number of effective cases were 12 (80%) in the SG group, 13 (56.5%) in the PS group, and 17 (65.4%) in the AO group, respectively. No serious adverse events were observed. Conclusion: The findings suggest that methadone can be effectively and safely introduced across all three groups.