Clinical analgesic equivalence for morphine and hydromorphone with prolonged PCA

A morphine to hydromorphone equivalence ratio of 7:1 has become the accepted standard, but evidence supporting it comes from single dose studies performed before the advent of patient controlled analgesia (PCA). We compared morphine and hydromorphone use with PCA in bone marrow transplantation patients who required opioids for the control of severe oral mucositis over several days or weeks. An exploratory analysis of clinical records from 102 patients (981 patient days) who used PCA opioids for varying periods of up to 50 days suggested a morphine to hydromorphone use ratio of 3:1. To clarify this observation, we studied a subset of patients under matched conditions. During a 7 day window in which mean oral mucositis severity did not vary across drug use groups and pain scores did not vary over time, patients in both groups gave equal pain relief satisfaction scores. Thirty-six patients who used morphine and 21 who used hydromorphone contributed data on pain, satisfaction with pain control, and drug consumption. We observed an average morphine/hydromorphone ratio of 3:1. This differs markedly from historical single dose studies used in published dose equivalency recommendations implying that other equivalency ratios in clinical use may be inappropriate.

Use of patient-controlled analgesia for pain control for children receiving bone marrow transplant

We report 2 years' experience managing 39 preteen (ages 4-12 years) children with patient-controlled analgesia (PCA) for pain associated with bone marrow transplantation (BMT). We prescribed morphine or hydromorphone PCA (starting bolus 20 micrograms/kg morphine or 2 micrograms/kg hydromorphone) with or without continuous infusion (CI), for a period of 6-74 days. The duration of PCA use (median 19 days) depended upon severity of mucositis or other painful conditions. The peak morphine use was on the 11th day after BMT. We prescribed CI opioids in addition to PCA, either at night or around the clock, in 52% of patients. Ninety-five percent of children successfully mastered PCA to control pain associated with BMT. We observed no instances of drug misuse, parental tampering, accidental overdose, or difficulty weaning from opioids. We conclude that opioid PCA, with or without CI, over several days or weeks is safe and effective for preteen children suffering BMT-related pain.