What is the recommended dosage of dexamethasone (corticosteroid) for children with asthma?

Dexamethasone Dosage for Asthma in Children

For acute asthma exacerbations in children, use a single dose of oral dexamethasone 0.3 mg/kg (maximum 12 mg) as it is equally effective to a 5-day course of prednisolone while offering superior compliance and fewer side effects. 1, 2

Recommended Dosing Regimens

First-Line Approach

• Single-dose dexamethasone: 0.3 mg/kg orally (maximum 12 mg) 1, 2
• This regimen is noninferior to 5 days of prednisolone (1 mg/kg/day) for mild-to-moderate exacerbations 1
• Provides similar efficacy with improved compliance (99.3% vs 96.0%) and significantly less vomiting (0% vs 5.7%) compared to multi-day prednisolone 1, 2

Alternative Two-Day Regimen

• Dexamethasone 0.6 mg/kg/day for 2 consecutive days (maximum 16 mg/day) 3, 4
• This higher-dose, two-day course is also noninferior to 5 days of prednisolone 3, 4
• May be considered for more severe exacerbations or when clinicians prefer a slightly longer steroid exposure 3

Critical Clinical Context

When NOT to Use Dexamethasone

• Dexamethasone is NOT recommended for chronic cough or non-specific cough in children 5
• In children with wheeze but without confirmed asthma, oral steroids showed no benefit and were associated with increased hospitalizations (p=0.058) 5
• For pertussis-associated cough, dexamethasone provides no significant benefit 5

Appropriate Use for Asthma

• Dexamethasone should only be used for acute asthma exacerbations, not for chronic asthma management 1, 2, 4
• For chronic asthma control, use inhaled corticosteroids (ICS) at 400 mcg/day beclomethasone equivalent, not oral steroids 5

Practical Advantages of Dexamethasone

Compliance Benefits

• Single-dose administration eliminates the need for parents to remember multiple days of medication 1, 2
• Significantly fewer children vomit dexamethasone (0-2.1%) compared to prednisolone (3-5.7%) 1, 2, 4
• No bitter taste issues that plague prednisolone 1, 6

Clinical Outcomes

• Similar relapse rates (7.4% vs 6.9%) compared to 5-day prednisolone course 2
• Equivalent symptom persistence at day 7 (56.6% vs 58.3%) 4
• Comparable hospitalization rates from ED (11% vs 12%) 2
• Fewer missed school days (13.2% vs 19.5%) 2

Important Caveats

Relapse Considerations

• One study found higher rates of requiring additional steroids within 14 days with single-dose dexamethasone (13.1% vs 4.2%, absolute difference 8.9%) 1
• This suggests some children may benefit from the two-day regimen (0.6 mg/kg/day × 2 days) rather than single-dose 3, 4
• Ensure parents understand when to return for reassessment 1

Concurrent Bronchodilator Therapy

• Dexamethasone should be used alongside inhaled beta-2 agonists (salbutamol/albuterol) 5, 7
• For severe exacerbations, consider adding ipratropium bromide 5
• Systemic steroids reduce relapses and hospital admissions but do not replace bronchodilator therapy 1

Dosing Summary by Severity

Mild-to-Moderate Exacerbations:

• Dexamethasone 0.3 mg/kg PO once (max 12 mg) 1, 2

Moderate-to-Severe Exacerbations:

• Dexamethasone 0.6 mg/kg/day PO for 2 days (max 16 mg/day) 3, 4
• Alternative: Prednisolone 1-2 mg/kg/day for 3-5 days (max 40-60 mg/day) 5

Note: The 2021 systematic review of asthma exacerbation guidelines confirms oral corticosteroid dosing consensus, with dexamethasone at 0.6 mg/kg and prednisolone at 1-2 mg/kg per day 5