Safety and Efficacy of Low-Dose Versus High-Dose Parenteral Ketorolac for Acute Pain Relief in Patients 65 Years and Older in the Emergency Department

Background There is limited data surrounding acute pain management in elderly ED patients. Ketorolac is a potent non steroidal anti-inflammatory drug (NSAID) with dose/duration-dependent side effects. There is evidence that an analgesic ceiling effect exists for parenteral ketorolac doses greater than 10 milligrams (mg); however, this has not been studied in patients 65 years and older. Methods This was a retrospective chart review of ED patients 65 years and older who received at least one dose of parenteral ketorolac. Patients were separated into two cohorts based on the ketorolac dose received: 15 mg IV or 30 mg intramuscular (IM) and 30 mg IV or 60 mg IM. The primary objective was to evaluate the analgesic efficacy of parenteral ketorolac doses measured as needing rescue analgesia from 30 minutes to 2 hours after ketorolac administration. Secondary objectives included changes in pain scores and the occurrence of adverse drug events commonly associated with ketorolac. Results Two-hundred and sixty patients received ketorolac doses of 15 mg IV or 30 mg IM, and 52 received 30 mg IV or 60 mg IM. The primary outcome occurred in seven of 52 patients who received ketorolac 30 mg IV or 60 mg IM and 17 of 260 patients who received ketorolac 15 mg IV or 30 mg IM (13.5% vs. 6.5%, p=0094; OR: 2.22, 95% CI: 0.87-5.67). The average change in pain scores were 2.9 (& PLUSMN;3.1) and 2.8 (& PLUSMN;2.9) for patients who received doses 30 mg IV or 60 mg IM compared to doses 15 mg IV or 30 mg IM, respectively (p=0.154). The occurrence of adverse events was low in both groups. Conclusion Parenteral ketorolac doses of 15 mg IV or 30 mg IM did not demonstrate a greater need for rescue analgesia compared to doses of 30 mg IV or 60 mg IM.