Continuous subcutaneous infusion of morphine vs. hydromorphone: a controlled trial

Seventy-four patients were included in a double-blind, randomized, controlled trial comparing the analgesic efficacy and adverse effects of hydromorphone and morphine delivered by continuous subcutaneous infusion. Patients completed the Memorial Pain Assessment Card and a checklist of opioid-related adverse effects immediately before commencing subcutaneous infusion and 24, 48, and 72 hours later. An assessment tool was developed for the 60 patients who were too ill to complete their own questionnaire. The tool demonstrated excellent inter-rater reliability. Thirty-four percent of patients in the hydromorphone group and 27% of those in the morphine group died before completion of the study (P = 0.66). The hydromorphone group required more analgesia for breakthrough pain in the first 24 hours of the study (P = 0.03) and had a greater improvement in the behavior of frowning on movement and the comfort visual analogue scale (P = 0.08) over the course of the study. Adverse effects were rare and similar in both groups. This study found hydromorphone to be at least as effective as morphine when delivered by continuous subcutaneous infusion.