What is the oral (PO) dose of ketorolac (tromethamine) for an adult patient with moderate to severe pain, considering age and renal function?

Oral Ketorolac Dosing

For adults aged 17-64 years, oral ketorolac is dosed as 20 mg once, followed by 10 mg every 4-6 hours as needed, not exceeding 40 mg/day, and must only be used as continuation therapy after IV or IM ketorolac, with total combined duration not exceeding 5 days. 1

Standard Dosing by Age and Risk Factors

Adults Age 17-64 Years (Standard Risk)

• Initial dose: 20 mg PO once 1
• Maintenance: 10 mg every 4-6 hours as needed 1
• Maximum daily dose: 40 mg/day 1
• Critical restriction: Oral formulation should NOT be given as an initial dose—it must follow IV or IM ketorolac administration 1

High-Risk Populations (Age ≥65 years, renal impairment, or weight <50 kg)

• Initial dose: 10 mg PO once 1
• Maintenance: 10 mg every 4-6 hours as needed 1
• Maximum daily dose: 40 mg/day 1

Critical Duration Limitations

The combined duration of IV/IM ketorolac plus oral ketorolac must not exceed 5 days in adults. 1 This strict limitation exists because cumulative risks of gastrointestinal bleeding, renal impairment, and operative site bleeding increase substantially with prolonged therapy. 2

Dosing Interval Requirements

• Minimum dosing interval: 4-6 hours between doses 1
• Do not shorten this interval even if pain persists 1
• Use the minimum effective dose for each individual patient 1

Absolute Contraindications to Oral Ketorolac

Oral ketorolac is not approved for patients under age 17 years. 1

Additional contraindications include:

• Active peptic ulcer disease 3
• History of gastrointestinal bleeding 3, 4
• Severe renal impairment 4
• Perioperative pain in coronary artery bypass graft surgery 3
• Concurrent use with other NSAIDs (including ibuprofen) 4

Key Safety Considerations

NSAID Stacking Risk

Never combine ketorolac with other NSAIDs such as ibuprofen. 4 If a patient has recently taken ibuprofen, wait 6-8 hours after the last ibuprofen dose before administering ketorolac to allow for adequate drug clearance. 4 The toxicities of multiple NSAIDs are additive without providing additional analgesic benefit. 4

High-Risk Patient Populations Requiring Extreme Caution

• Age ≥60 years (increased risk of all NSAID-related adverse effects) 3, 4
• History of peptic ulcer disease (5% risk of recurrent bleeding within 6 months) 3
• Concurrent anticoagulant use (increases GI bleeding risk 5-6 times) 3, 4
• Compromised fluid status or dehydration 4
• Pre-existing renal insufficiency 4
• History of cardiovascular disease or hypertension 4

Mandatory Monitoring Requirements

For patients receiving ketorolac, baseline assessment should include:

• Blood pressure 4
• BUN and creatinine 4
• Liver function tests 4
• Complete blood count 4
• Fecal occult blood 4

Immediate Discontinuation Criteria

Stop ketorolac immediately if:

• BUN or creatinine doubles 4
• Hypertension develops or worsens 4
• Liver function tests increase >3 times upper limit of normal 4
• Any signs of gastrointestinal bleeding occur 4

Clinical Context: Analgesic Ceiling Effect

Research demonstrates that ketorolac exhibits an analgesic ceiling effect, with 10 mg potentially representing the ceiling dose. 5, 6 A randomized controlled trial showed that intravenous ketorolac at 10 mg, 15 mg, and 30 mg provided similar analgesic efficacy in ED patients with moderate to severe pain, with no incremental benefit at higher doses. 6 Despite this evidence, clinical practice patterns show that 97% of patients receive doses above the ceiling dose. 5

Alternative Analgesic Strategies

If additional pain control is needed beyond the maximum ketorolac dose:

• Acetaminophen can be safely alternated with ketorolac (650 mg every 4-6 hours, maximum 3-4 grams/day) as these medications have non-overlapping toxicity profiles 4
• Opioid analgesics are safe alternatives that do not share NSAID toxicity profiles 4
• Consider multimodal analgesia rather than exceeding ketorolac dosing limits 4