Dexamethasone Dosing for Croup in Infants: Oral Administration of Injectable Formulation
For an infant with croup, administer dexamethasone 0.6 mg/kg orally using the injectable formulation (maximum dose 16 mg), which is the standard recommended dose by the American Academy of Pediatrics. 1, 2
Dosing Specifics
- Standard dose: 0.6 mg/kg (maximum 16 mg) given as a single dose 1, 2
- The injectable formulation can be administered orally and is equally effective as intramuscular or intravenous routes 1, 2
- For infants, calculate the dose based on weight in kilograms: multiply the infant's weight by 0.6 mg/kg 1
Lower Dose Alternative
While 0.6 mg/kg is the guideline-recommended dose, research demonstrates that 0.15 mg/kg is equally effective for both mild-to-moderate and moderate-to-severe croup 3, 4, 5:
- A 2007 randomized trial showed no difference in croup scores between 0.15 mg/kg and 0.6 mg/kg in hospitalized children with moderate to severe croup 5
- A 1995 study confirmed that 0.15 mg/kg is as effective as 0.3 or 0.6 mg/kg in relieving symptoms and reducing hospitalization duration 4
- The lower dose may be considered to minimize potential side effects while maintaining efficacy 3, 6
Clinical Onset and Duration
- Onset of action: as early as 30 minutes after administration, with statistically significant improvement by 30 minutes 1, 2, 3
- Duration of action: 24-72 hours of sustained relief 1, 2
- No tapering required for single-dose regimen 1, 2
Route of Administration
- Oral route is preferred when the infant can tolerate it—equally effective as IM or IV and avoids injection pain 1, 2
- All three routes (oral, IM, IV) demonstrate equivalent efficacy 1, 2
- Simply give the injectable dexamethasone solution by mouth 1, 2
Adjunctive Therapy for Severe Cases
If the infant has moderate to severe croup with significant respiratory distress (prominent stridor, significant retractions, agitation):
- Add nebulized epinephrine while waiting for dexamethasone to take effect 1, 7, 2
- Epinephrine dose: 0.5 mL/kg of 1:1000 solution (maximum 5 mL) by nebulizer 7, 2
- Epinephrine provides immediate but short-term relief, while dexamethasone provides longer-lasting benefit 1, 2
Important Caveats
- For severe croup requiring repeat dosing: administer another dexamethasone dose plus nebulized epinephrine regardless of timing of the initial dose 1, 2
- Monitor for at least 2 hours after epinephrine administration for potential rebound airway obstruction 8
- Ensure the infant can maintain adequate oxygenation; provide supplemental oxygen if needed 8