Oral versus Intravenous Opioid Dosing for the Initial Treatment of Acute Musculoskeletal Pain in the Emergency Department

The objective was to compare the time to medication administration, the side effects, and the analgesic effect at sequential time points after medication administration of an oral treatment strategy using oxycodone solution with an intravenous (IV) treatment strategy using morphine sulfate for the initial treatment of musculoskeletal pain in emergency department (ED) patients. This was a prospective randomized clinical trial of patients > 6 years old who were going to receive IV morphine sulfate for the treatment of musculoskeletal pain but did not yet have an IV. Consenting patients were randomized to have the treating physician order either 0.1 mg/kg morphine sulfate IV or 0.125 mg/kg oxycodone orally in a 5 mg/5 mL suspension as their initial treatment for pain. The time from the placement of the order to the administration of the medication was recorded. Pain was measured using a 100-mm visual analog scale (VAS) and recorded at 0, 10, 20, 30 and 40 minutes after drug administration. A total of 405 eligible patients were identified during the study period; 328 (81.0%) patients consented to be in the study. A total of 158 patients were randomized to the IV morphine sulfate treatment group, and 162 were randomized to the oral oxycodone treatment group. Of the patients who were randomized to IV therapy, 34 were withdrawn from the study prior to drug administration; leaving 125 patients in the IV group for analysis. Of the patients who randomized to oral therapy, 22 were withdrawn from the study prior to drug administration, leaving 140 patients for analysis. No serious adverse events were detected. There was a 12-minute difference between the median time of the order and the administration of oral oxycodone (8.5 minutes) and IV morphine (20.5 minutes). The mean percent change in VAS score was larger for patients in the IV therapy group than those in the oral therapy group at 10 and 20 minutes. At 30 and 40 minutes, the authors could no longer detect a difference. The satisfaction scale score was higher after treatment for the morphine group (median = 4; interquartile range [IQR] = 4 to 5) than for the oxycodone group (median = 4; IQR = 2 to 5; p = 0.008). The oral loading strategy was associated with delayed onset of analgesia and decreased patient satisfaction, but a shorter time to administration. The oral loading strategy using an oxycodone solution provided similar pain relief to the IV strategy using morphine 30 minutes after administration of the drug. Oral 0.125 mg/kg oxycodone represents a feasible alternative to 0.1 mg/kg IV morphine in the treatment of severe acute musculoskeletal pain when difficult or delayed IV placement greater than 30 minutes presents a barrier to treatment.