A 46-year-old man with no significant past medical history presents to the emergency department (ED) with right flank pain and nausea. A computed tomography scan reveals a 5-mm ureteral stone with no obstruction or hydronephrosis. You are planning on starting him on intravenous (IV) ketorolac for pain. What is the most appropriate dose?
Ketorolac tromethamine is a highly effective nonsteroidal anti-inflammatory drug (NSAID). As a non-opiate analgesic, it is often the optimal first choice for the treatment of acute conditions such as flank, abdominal, musculoskeletal, and headache pains.2 While it is not associated with euphoria, withdrawal effects, or respiratory depression (like its opiate analgesic counterparts), ketorolac carries a US Food and Drug Administration black box warning for gastrointestinal, cardiovascular, renal, and bleeding risks.3
NSAIDs are known to have a “ceiling dose,” a dose at which maximum analgesic benefit is achieved; higher doses will not provide further pain relief. Higher doses of ketorolac may be used when anti-inflammatory effects of NSAIDs are desired, but they are likely to cause more adverse effects.4 Available data describe the analgesic ceiling dose of ketorolac as 10 mg across dosage forms.4,5 Yet, the majority of research and the majority of health care providers in current practice use higher doses of 20 to 60 mg. The US Food and Drug Administration label provides for a maximum dose of 60 mg/d.3
In one recent study, ketorolac was prescribed above its ceiling dose of 10 mg in atleast 97% of patients who received IV doses and in at least 96% of patients receiving intramuscular (IM) doses in a US emergency department.6 If ketorolac 10 mg 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.
Though often used at higher doses, 10 mg of ketorolac is enough for pain
This randomized double-blind trial evaluated the effectiveness of 3 different doses of IV ketorolac for acute pain in 240 adult patients, ages 18 to 65 years, presenting to an ED with acute flank, abdominal, musculoskeletal, or headache pain.1 Acute pain was defined as onset ≤30 days.
Patients were randomized 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, and the syringes 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 numerical pain score at 30 minutes after ketorolac administration; secondary outcomes included the occurrence of adverse events and the use of rescue medication.
The groups were similar in terms of demographics and baseline vital signs. The mean age of the participants was 39 to 42 years. 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 pain for an average of 1.5 to 3.5 days.
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