Recommended Dose of Ketorolac for an 18 kg Child
The recommended intravenous dose of ketorolac for an 18 kg child is 0.5 mg/kg (9 mg) every 6 hours, with a maximum daily dose of 40 mg/kg/day. 1
Dosing Guidelines Based on Route of Administration
Intravenous (IV) Administration
- Initial dose: 0.5 mg/kg (9 mg for an 18 kg child) 1
- Maintenance: Can be given as bolus injections of 0.5 mg/kg every 6 hours or as an infusion of 0.17 mg/kg/hour 1
- Maximum daily dose: Should not exceed 40 mg/day 1, 2
- Maximum duration: Treatment should be limited to 48 hours for IV administration 1
Oral Administration (for transition from IV)
- Recommended oral dose: 0.25 mg/kg (4.5 mg for an 18 kg child) 1
- Maximum oral daily dose: 1.0 mg/kg/day (18 mg for an 18 kg child) 1
- Maximum duration: Oral therapy should not exceed 7 days 1
Age-Related Considerations
- Ketorolac is not recommended for use in infants under 1 year of age 1
- For children weighing less than 40 kg (including an 18 kg child), weight-based dosing is essential 3
- Clearance of ketorolac (expressed as L/h/kg) decreases with age from infancy 4
Important Clinical Considerations
Efficacy
- Ketorolac provides potent analgesia comparable to opioids such as morphine and more effective than codeine 1
- When combined with opioids, ketorolac exhibits marked opioid-sparing effects, allowing lower opioid doses 1
Safety Considerations
- Unlike opioids, ketorolac does not cause respiratory depression, nausea/vomiting, urinary retention, or sedation 1
- Ketorolac has reversible antiplatelet effects due to inhibition of thromboxane synthesis 1
- Bleeding time may be slightly increased but usually remains within normal values 1
- Monitor for potential adverse effects including gastrointestinal symptoms and renal function 2
Duration of Therapy
- The combined duration of IV/IM and oral ketorolac should not exceed 5 days 5
- Average length of therapy in pediatric studies was 3.4 days (range 1-12 days) 2
Pharmacokinetic Considerations
- Children have a larger volume of distribution (up to 2-fold) compared to adults 1
- Plasma clearance is higher in children, likely due to lower plasma protein binding 1
- Despite these differences, elimination half-life is similar to adults (4-6 hours) 1, 6
- A dosing regimen of 0.5 mg/kg every 6 hours maintains adequate analgesic concentrations in children 9 months to 16 years of age 4
Common Pitfalls to Avoid
- Avoid intramuscular injections in children unless IV access is unavailable 1
- Do not exceed the recommended maximum daily dose or duration of therapy 5, 1
- Use the lowest effective dose for the shortest duration consistent with treatment goals 5
- Remember that ketorolac oral formulation should not be given as an initial dose; it should only be used as continuation therapy after IV/IM dosing 5