What is the recommended intravenous dose of ketorolac for an adult with moderate to severe pain, and how should it be adjusted for patients aged 65 years or older or with impaired renal function?

Ketorolac Intravenous Dosing

For adults under 65 years with normal renal function, administer 30 mg IV ketorolac over at least 15 seconds every 6 hours (maximum 120 mg/day), but for patients ≥65 years, those with renal impairment, or weighing <50 kg, reduce the dose to 15 mg IV every 6 hours (maximum 60 mg/day), with treatment duration not exceeding 5 days. 1

Standard Adult Dosing (<65 years, normal renal function, ≥50 kg)

• Single-dose treatment: 30 mg IV administered over no less than 15 seconds 1
• Multiple-dose regimen: 30 mg IV every 6 hours, with maximum daily dose of 120 mg 1
• The analgesic effect begins in approximately 30 minutes with maximum effect at 1-2 hours, lasting 4-6 hours 1

Dose Adjustments for High-Risk Populations

Three patient groups require mandatory dose reduction to 15 mg IV every 6 hours (maximum 60 mg/day): 1

• Patients ≥65 years of age
• Patients with renal impairment
• Patients weighing <50 kg (110 lbs)

Rationale for Age-Based Dose Reduction

The pharmacokinetic profile changes significantly in elderly patients, justifying the 50% dose reduction:

• Plasma ketorolac concentrations are 10% higher in patients ≥65 years 2
• Terminal elimination half-life increases by 37% (4.52 hours vs 3.31 hours) 2
• Area under the curve (AUC) increases by 28% in older adults 2
• Residence time is 36% longer in elderly patients (6.02 hours vs 4.44 hours, p=0.003) 2

Evidence Supporting Lower Dosing

Recent high-quality research demonstrates that lower ketorolac doses provide equivalent analgesia with potentially improved safety:

• A 2017 randomized controlled trial of 240 ED patients showed no difference in pain reduction at 30 minutes between 10 mg, 15 mg, and 30 mg IV doses, with all groups achieving substantial pain relief (numeric rating scale reduction of approximately 2.5-3.0 points) 3
• A 2021 noninferiority trial found that 10 mg, 20 mg, and 30 mg IV doses produced similar analgesic efficacy in renal colic, with median pain score improvements from 90 mm to 40-50 mm at 30 minutes (p<0.05) 4
• A 2023 retrospective study of 312 elderly ED patients (≥65 years) found no significant difference in need for rescue analgesia between lower doses (15 mg IV/30 mg IM) versus higher doses (30 mg IV/60 mg IM), with 6.5% vs 13.5% requiring rescue (p=0.094) 5

Critical Administration Guidelines

Proper administration technique is essential to minimize adverse effects: 1

• IV bolus must be given over no less than 15 seconds (never as rapid push)
• Correct hypovolemia prior to administration to reduce renal risk 1
• Do not mix in small volumes with morphine sulfate, meperidine, promethazine, or hydroxyzine (causes precipitation) 1

Duration of Therapy Limitations

Ketorolac therapy must not exceed 5 days regardless of route or dose 1

• Patients should be switched to alternative analgesics as soon as possible 1
• For breakthrough pain, do not increase dose or frequency; instead consider supplementing with low-dose opioids unless contraindicated 1

Role in Multimodal Analgesia

Ketorolac serves as an effective component of opioid-sparing regimens:

• A single 30 mg IV dose of ketorolac showed equivalent procedural pain control to 4 mg IV morphine in critically ill adults undergoing chest tube removal 6
• Perioperative IV ketorolac decreases postoperative opioid requirements, pain scores, hospitalization costs, and length of stay in pediatric orthopedic procedures 6
• NSAIDs including ketorolac provide opioid-sparing effects in the 2-3 days following major gastrointestinal surgery 6

Common Pitfalls to Avoid

Do not use higher doses assuming greater efficacy - the analgesic ceiling effect occurs at approximately 10 mg IV, with doses above this providing no additional pain relief while potentially increasing adverse effects 3, 4

Do not forget the mandatory dose reduction in elderly patients - failure to reduce the dose to 15 mg IV in patients ≥65 years exposes them to 28% higher drug exposure without additional benefit 2, 1

Do not exceed 5-day treatment duration - prolonged NSAID use significantly increases risk of gastrointestinal bleeding, renal impairment, and cardiovascular events 1

Do not administer as rapid IV push - the bolus must be given over at least 15 seconds to minimize adverse effects 1