Comparing two doses of intramuscular ketorolac for treatment of acute musculoskeletal pain in a military emergency department

Am J Emerg Med. 2021 Dec;50:142-147. doi: 10.1016/j.ajem.2021.07.054. Epub 2021 Jul 31.


Study objective: The goal of the study was to assess a low-dose versus a high-dose of intramuscular (IM) ketorolac for non-inferiority in adults with acute MSK pain in an emergency department (ED).

Methods: This was a single-blinded, randomized controlled, non-inferiority trial of adults presenting to an ED with a chief complaint of acute MSK pain. Patients were randomized to either a 15 mg or a 60 mg IM ketorolac dose. The primary outcome was the mean difference of change in pain from baseline to 60-min between the two groups as reported on a 100-mm (mm) visual analog scale (VAS). Secondary outcomes included the mean difference of change in VAS scores at 30-min and the incidence of reported adverse effects associated with the administration of ketorolac.

Results: One hundred ten patients were randomized with 55 in each group. The mean difference in pain between groups at 60-min (0.2 mm [95% CI -8.5-8.7]; p = .98) and 30 min (-1.7 mm [95% CI -8.5-5.1; p = .63) was less than the predetermined non-inferiority margin of 13 mm. There were no major adverse effects reported. Minor adverse effects were more frequent in the 60 mg group (n = 9; 16.4% vs. n = 1; 1.8%; p = .016) with burning at the injection site being the most commonly reported.

Conclusions: A 15 mg dose of IM ketorolac was found to be non-inferior to a 60 mg dose for acute MSK pain in adults presenting to the ED. Discontinuing the practice of ordering 60 mg doses of IM ketorolac in place of a lower dose for acute MSK pain should be considered.

Keywords: Analgesia; Emergency department; Intramuscular; Ketorolac; Musculoskeletal; Non-inferiority; Pain control.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Acute Pain / drug therapy*
  • Adolescent
  • Adult
  • Anti-Inflammatory Agents, Non-Steroidal / administration & dosage*
  • Anti-Inflammatory Agents, Non-Steroidal / adverse effects
  • Emergency Service, Hospital
  • Female
  • Hospitals, Military*
  • Humans
  • Injections, Intramuscular
  • Ketorolac / administration & dosage*
  • Ketorolac / adverse effects
  • Male
  • Middle Aged
  • Musculoskeletal Pain / drug therapy*
  • Pain Measurement
  • Single-Blind Method
  • United States


  • Anti-Inflammatory Agents, Non-Steroidal
  • Ketorolac