Ketorolac Intramuscular Administration
Recommended Dosing
For adults aged 17-64 years, administer ketorolac 15-30 mg IM every 6 hours, with a maximum daily dose of 120 mg and treatment duration not exceeding 5 days. 1, 2
Age-Specific Dosing Adjustments
- Patients ≥65 years: Use the lower dose of 15 mg IM every 6 hours due to increased systemic exposure, prolonged elimination half-life (37% longer), and 28% higher AUC compared to younger adults 1, 3
- Patients aged 17-64 years: Standard dosing of 15-30 mg IM every 6 hours is appropriate 1
- Pediatric patients: Ketorolac is not indicated for use in children via IM route; if parenteral administration is necessary in children, IV route is preferred at 0.5 mg/kg followed by 1.0 mg/kg every 6 hours (maximum 90 mg/day for 48 hours) 2, 4
Maximum Duration
The combined duration of IM/IV ketorolac plus oral ketorolac must not exceed 5 days in adults. 1, 2 This strict limitation is critical to minimize dose-dependent adverse effects including GI bleeding, renal toxicity, and cardiovascular events 2
Absolute Contraindications
Ketorolac IM is contraindicated in the following patients 1, 2:
- Aspirin/NSAID-induced asthma (risk of severe, potentially fatal bronchospasm due to cross-reactivity)
- Active peptic ulcer disease or active GI bleeding
- Cerebrovascular hemorrhage or other active bleeding
- Pregnancy ≥30 weeks gestation (risk of premature closure of fetal ductus arteriosus)
- Advanced renal impairment or risk of renal failure
- Concurrent use of other NSAIDs (additive toxicity without additional analgesic benefit) 5
High-Risk Populations Requiring Caution
Use ketorolac with extreme caution or avoid in 1, 2:
- Age ≥60 years: Increased risk of acute renal failure, GI bleeding; use reduced dose of 15 mg IM every 6 hours
- Compromised fluid status or dehydration: Heightened nephrotoxicity risk
- Pre-existing renal insufficiency: Monitor closely; discontinue if BUN or creatinine doubles 5
- History of peptic ulcer disease or GI bleeding: Even without active disease, risk is substantially elevated
- Concurrent anticoagulant therapy: Ketorolac reversibly inhibits platelet aggregation and prolongs bleeding time 4, 6
- Concurrent nephrotoxic medications: Renal impairment occurs in 8.7% with similar aminoglycoside drugs 5
- Hepatic impairment: Use with caution; 15% of patients may develop borderline liver enzyme elevations 2
- Cardiovascular disease or hypertension: Increased risk of thrombotic cardiovascular events 2
Required Monitoring
Baseline Assessment
Before initiating ketorolac, obtain 1, 5:
- Blood pressure
- BUN and creatinine
- Liver function tests (ALT, AST)
- Complete blood count (CBC)
- Fecal occult blood test
Ongoing Monitoring
- Repeat laboratory tests every 3 months for long-term therapy (though duration should not exceed 5 days for IM/IV use) 1
- Discontinue immediately if: 5
- BUN or creatinine doubles from baseline
- Hypertension develops or worsens
- Liver enzymes increase >3 times upper limit of normal
- Signs of GI bleeding (melena, hematemesis, epigastric pain)
- Development of rash or fever (potential DRESS syndrome) 2
Common Adverse Effects
Patients should be counseled about 1, 2:
- Edema and fluid retention
- Drowsiness and dizziness
- Gastrointestinal upset (dyspepsia, nausea)
- Increased diaphoresis
- Injection site burning (more common with 60 mg doses) 7
Clinical Pearls
Ketorolac demonstrates equivalent analgesic efficacy to opioids without respiratory depression, sedation, or opioid-related adverse effects. 8, 1 In emergency department studies, oral ketorolac showed equivalent efficacy to acetaminophen/codeine for acute low back pain, with significantly fewer adverse events (34% vs 64%) and better tolerability 8
Dose Equivalence
Recent evidence demonstrates that 15 mg IM ketorolac is non-inferior to 60 mg IM for acute musculoskeletal pain, with significantly fewer minor adverse effects (1.8% vs 16.4%) 7 Similarly, in patients ≥65 years, 15 mg IV or 30 mg IM doses did not demonstrate greater need for rescue analgesia compared to higher doses 9
NSAID Stacking Warning
Never administer ketorolac within 6-8 hours of ibuprofen or other NSAIDs. 5 Wait for complete ibuprofen clearance (half-life ~2 hours, requiring 6-8 hours for adequate elimination) to avoid additive GI, renal, and cardiovascular toxicities without additional analgesic benefit 5
Safe Combination Therapy
Ketorolac can be safely alternated with acetaminophen 650 mg every 4-6 hours (maximum 3-4 grams/day), as these have different mechanisms and non-overlapping toxicity profiles 5 This provides more continuous pain coverage without exceeding maximum daily doses of either medication 5