ABSTRACT
Background: The efficacy and safety of continuous subcutaneous injection (CSCI) of hydromorphone hydrochloride (HM) for titration of moderate to severe cancer pain have yet to be evaluated. Methods: We retrospectively analyzed the patients underwent CSCI of HM from Feb. 2020 to Oct. 2021 in Kitano Hospital, Osaka, Japan. The concentration of HM was 0.20 mg/ml to 1.0 mg/ml in saline depending on the patient. Haloperidol was added to a concentration of 0.5 mg/ml for a total of 10 ml. CSCI was performed using a portable small syringe driver. The dose was titrated between 0.05 ml/h and 1.0 ml/h to achieve adequate relief of pain without unacceptable side effects. Results: A total of 37 patients including 1 opioid-naive patient were examined. The median dose of HM at the initiation and completion of titration was 1.92 and 2.40 mg/day, respectively. The median time to titration completion was 2 days. Titration completion rate within 3 days was observed in 33 patients (89%). Remarkable effect to pain (at least 66% improvement in numerical rating scale [NRS]) was observed in 33 patients (89%), efficacy (33 to 66% improvement in NRS) in 3 patients (8.1%), and inefficacy in 1 patient (2.7%). Adverse events included Common Terminology Criteria for Adverse Events Grade 2 drowsiness in 3 patients (8.1%) and Grade 2 hypotension in 1 patient (2.7%), both of which improved with reduction or discontinuation of HM. Conclusion: CSCI of HM was simple and safe, and produced rapid and effective pain control for moderate to severe cancer pain.