Subcutaneous methadone in terminally ill patients: manageable local toxicity

Methadone has been found to be useful in pain uncontrolled by large doses of conventional opioids such as hydromorphone and morphine. While the subcutaneous route is effective and may afford cost-savings over the intravenous route in patients unable to take oral medication, its utility for the administration of methadone may be hampered by local toxicity, specifically erythema and induration. To examine the issue of limiting toxicity, we analyzed our inpatient hospice experience in six consecutive patients who received subcutaneous methadone for severe cancer pain. We confirm the high incidence of local toxicity, but note that the severity is subject to considerable individual variation. Furthermore, toxicity is uniformly manageable by site rotation and the use of dexamethasone infused concurrently with the methadone. We recommend that the infusion of subcutaneous methadone should be considered in the appropriate patients who can be closely monitored.