A case that had been using high-dose fentanyl patches for chronic pain for a long time reduced opioid usage by opioid switching with measuring serum concentration

Abstract

Fentanyl patch (FP) has been available for more than 10 years for the management of intractable chronic pain. Indications for chronic pain is still problematic in terms of duration and dosage. In this study, we planned to switch to oxycodone while measuring serum concentrations of fentanyl in patients who had been using long-term, very high-dose FP for intractable chronic pain due to familial Mediterranean fever, an incurable disease, and musculoskeletal disease. The patient was switched to oxycodone while serum fentanyl concentrations were measured. The patient was initially managed as an inpatient and was able to reduce the opioid dose to about 1/3 of the original dose over 21 weeks, while improving activities of daily living and quality of life.