Morphine Dosing in Acute Pain: How Much Is Enough?

Underdosing of opioid analgesia is a significant problem in emergency medicine. Although many dosing regimens for intravenous morphine have been studied, 0.10 mg/kg generally is recommended as an acceptable starting dose for treating patients with acute pain. Unfortunately, many physicians start much lower. In a prospective, randomized, placebo-controlled, double-blind study, researchers compared the effects of morphine at doses of 0.10 mg/kg and 0.15 mg/kg in 280 adult patients (age range, 21–65) who presented with pain of less than 7 days’ duration and who were deemed to require opioid analgesia by an attending emergency physician.

All patients received an initial dose of 0.10 mg/kg of morphine. After 30 minutes, those randomized to the hi…