What is the recommended dose of dexamethasone (corticosteroid) for acute asthma exacerbations?

Dexamethasone Dosing for Acute Asthma Exacerbations

For acute asthma exacerbations, intravenous hydrocortisone 200 mg every six hours is recommended for patients who are seriously ill or vomiting, while oral prednisolone 30-60 mg daily is the standard oral therapy for 3-10 days without tapering. 1, 2

Corticosteroid Options and Dosing

First-Line Injectable Corticosteroid:

• Intravenous hydrocortisone: 200 mg every six hours for seriously ill patients or those who are vomiting 1

First-Line Oral Corticosteroid:

• Prednisolone: 30-60 mg daily for adults for 3-10 days 1, 2
• No tapering needed for short courses (up to 10 days) 1, 2

Alternative Corticosteroid Options:

• Dexamethasone (oral):
  • Single dose of 12 mg for adults 3
  • Two doses of 0.3 mg/kg given 24 hours apart for children 4

Treatment Algorithm for Acute Asthma

1. Assess severity of exacerbation:

   • Mild-to-moderate: Patient can speak in sentences, respiratory rate <25/min, PEF >50% predicted
   • Severe: Too breathless to complete sentences, respiratory rate >25/min, PEF <50% predicted
   • Life-threatening: Silent chest, cyanosis, PEF <33% predicted, bradycardia/hypotension 1

2. Initial management:

   • High-dose inhaled β-agonists (salbutamol 5 mg or terbutaline 10 mg nebulized)
   • Systemic corticosteroids immediately 1

3. Corticosteroid administration based on severity:

   • For severe/life-threatening exacerbations or patients unable to take oral medications:
     • IV hydrocortisone 200 mg every six hours 1
   • For mild-moderate exacerbations with oral intake possible:
     • Oral prednisolone 30-60 mg daily for 3-10 days 1

4. Monitoring response:

   • Measure peak expiratory flow 15-30 minutes after starting treatment
   • Continue oxygen therapy as needed
   • Adjust treatment frequency based on response 1

Important Clinical Considerations

• Oral administration is equally effective as IV administration for non-life-threatening exacerbations 2
• Patients should not be discharged until symptoms have stabilized with peak expiratory flow above 75% of predicted value 1
• While dexamethasone has shown promise as an alternative (with better compliance due to fewer doses), it did not quite meet noninferiority criteria compared to prednisolone in adult studies 3
• Inhaled corticosteroids should not be used routinely to treat acute exacerbations 5

Cautions and Contraindications

• Avoid sedation as it is contraindicated in acute asthma 1
• Antibiotics should only be given if bacterial infection is present 1
• Short courses of systemic corticosteroids can cause adverse effects including mental health impacts, hypertension, and gastrointestinal issues 2

Follow-up

• Schedule follow-up within 1-2 weeks of an exacerbation to assess recovery and adjust maintenance therapy 2
• Optimize controller medications to prevent future exacerbations requiring systemic corticosteroids 2

The evidence strongly supports using systemic corticosteroids for acute asthma exacerbations, with intravenous hydrocortisone for severe cases and oral prednisolone as the standard oral therapy, while dexamethasone remains a promising alternative that may offer better compliance.