Less Is More When It Comes to Ketorolac for Pain

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It’s time to review our dosing with ketorolac for acute pain management.



Practice Changer

A 46-year-old man with no significant medical history presents to the emergency department (ED) with right flank pain and nausea. CT reveals a 5-mm ureteral stone with no obstruction or hydronephrosis. You are planning to start him on IV ketorolac for pain. What is the most appropriate dose?

Ketorolac tromethamine is a highly effective NSAID. As a nonopiate analgesic, it is often the first choice for the treatment of acute pain in the flank, abdomen, musculoskeletal system, or head.2 While it is not associated with euphoria, withdrawal effects, or respiratory depression (like its opiate analgesic counterparts), ketorolac carries an FDA black-box warning for gastrointestinal, cardiovascular, renal, and bleeding risks.3

NSAIDs are known to have a “ceiling dose” at which maximum analgesic benefit is achieved; higher doses will not provide further pain relief. Higher doses of ketorolac may be used when the anti-inflammatory effects of NSAIDs are desired, but they are likely to cause more adverse effects.4 Available data describe the ceiling dose of ketorolac as 10 mg across dosage forms—yet the majority of research and most health care providers in current practice use higher doses (20 to 60 mg).4,5 The FDA-approved labeling provides for a maximum dose of 60 mg/d.3

In one recent study, ketorolac was prescribed above its ceiling dose in at least 97% of patients who received IV doses and at least 96% of those who received intramuscular (IM) doses in a US ED.6 If 10 mg of ketorolac is an effective analgesic dose, current practice exceeds the label recommendation to use the lowest effective dose. This study sought to determine the comparative efficacy of 3 different doses of IV ketorolac for acute pain management in an ED.


10 mg of ketorolac is enough for pain

This randomized double-blind trial evaluated the effectiveness of ketorolac in 240 adult patients (ages 18 to 65) presenting to an ED with acute flank, abdominal, musculoskeletal, or headache pain.1 Acute pain was defined as onset within the past 30 days.

Patients were randomly assigned to receive either 10, 15, or 30 mg of IV ketorolac in 10 mL of normal saline. A pharmacist prepared the medication in identical syringes, which were delivered in a blinded manner to the nurses caring for the patients. Pain (measured using a 0-to-10 scale), vital signs, and adverse effects were assessed at baseline and at 15, 30, 60, 90, and 120 minutes. If patients were still in pain at 30 minutes, IV morphine (0.1 mg/kg) was offered. The primary outcome was a numerical pain score at 30 minutes after ketorolac administration; secondary outcomes included the occurrence of adverse events and the use of rescue medication (morphine).

The treatment groups were similar in terms of demographics and baseline vital signs. Mean age was 39 to 42. Across the 3 groups, 36% to 40% of patients had abdominal pain, 26% to 39% had flank pain, 20% to 26% had musculoskeletal pain, and 1% to 11% had headache pain. Patients had experienced pain for an average of 1.5 to 3.5 days.

Continue to: Baseline pain scores...

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