What medications are used to treat acute asthma exacerbations?

Medications for Acute Asthma Exacerbation

Administer albuterol (2.5-5 mg via nebulizer or 4-8 puffs via MDI with spacer every 20 minutes for 3 doses), systemic corticosteroids (prednisone 40-60 mg orally), and oxygen to maintain saturation >90%, with ipratropium bromide (0.5 mg) added for moderate-to-severe exacerbations. 1, 2, 3

Initial Treatment Algorithm (First 15-30 Minutes)

Oxygen Therapy

• Administer supplemental oxygen immediately via nasal cannula or mask to maintain oxygen saturation >90% (>95% in pregnant patients or those with heart disease). 1, 2, 3
• Continue monitoring oxygen saturation continuously until clear response to bronchodilator therapy occurs. 1, 2

Short-Acting Beta-Agonists (First-Line Bronchodilator)

• Albuterol is the first-line treatment for all asthma exacerbations. 1, 2, 3
• Nebulizer dosing: 2.5-5 mg every 20 minutes for 3 doses, then 2.5-10 mg every 1-4 hours as needed. 4, 1, 3
• MDI with spacer dosing: 4-8 puffs every 20 minutes for up to 3 doses, then as needed. 4, 1, 3
• MDI with spacer is equally effective as nebulizer therapy when properly administered with appropriate technique. 4, 1
• For severe exacerbations (FEV1 or PEF <40% predicted), consider continuous nebulization of albuterol. 1, 3

Systemic Corticosteroids (Critical Early Intervention)

• Administer systemic corticosteroids immediately to all patients with moderate-to-severe exacerbations, as clinical benefits may not occur for 6-12 hours. 1, 5
• Adult dosing: Prednisone 40-60 mg orally in single or divided doses. 4, 1, 3
• Pediatric dosing: 1-2 mg/kg/day (maximum 60 mg/day). 4, 1, 3
• Oral administration is as effective as intravenous and less invasive. 1
• Alternative: IV methylprednisolone 1-2 mg/kg or hydrocortisone 200 mg IV every 6 hours if patient cannot tolerate oral medication. 4, 1

Reassessment at 15-30 Minutes

Monitoring Parameters

• Measure peak expiratory flow (PEF) or FEV1 before and after treatments. 1, 3
• Assess symptoms, vital signs, and oxygen saturation. 1, 3
• Response to treatment is a better predictor of hospitalization need than initial severity. 1, 2

Adjunctive Therapies for Moderate-to-Severe Exacerbations

Ipratropium Bromide

• Add ipratropium bromide to albuterol for all moderate-to-severe exacerbations. 1, 2, 3
• Dosing: 0.5 mg via nebulizer or 8 puffs via MDI every 20 minutes for 3 doses, then as needed. 4, 1, 3
• The combination reduces hospitalizations, particularly in patients with severe airflow obstruction. 1, 5
• Important caveat: Addition of ipratropium has not been shown to provide further benefit once the patient is hospitalized beyond the first 3 hours. 4, 5
• May be mixed in the same nebulizer with albuterol. 4

Intravenous Magnesium Sulfate

• Consider for severe refractory asthma or life-threatening exacerbations not responding to initial therapy. 1, 2, 3
• Adult dosing: 2 g IV over 20 minutes. 4, 1, 3
• Pediatric dosing: 25-75 mg/kg (maximum 2 g) IV over 20 minutes. 1
• Most effective when administered early in the treatment course. 3

Medications to Avoid

Methylxanthines (Theophylline)

• No longer recommended due to erratic pharmacokinetics, known side effects, and lack of evidence of benefit over selective inhaled beta-agonists. 4, 1
• Increased side effect profile without superior efficacy. 1

Subcutaneous Epinephrine or Terbutaline

• No proven advantage over inhaled beta-agonists. 4
• Epinephrine 0.3-0.5 mg subcutaneously or terbutaline 0.25 mg subcutaneously may be considered only if inhaled therapy is not available. 4
• IV epinephrine has been associated with 4% incidence of serious side effects. 4

Other Agents Not Recommended

• Leukotriene antagonists: Effectiveness during acute exacerbations is unproven. 4
• Sedatives: Should never be administered to patients with acute asthma exacerbation. 1, 3
• Antibiotics: Not generally recommended unless strong evidence of bacterial infection (pneumonia or sinusitis). 1
• Aggressive hydration: Not recommended for older children and adults. 1

Treatment Duration and Discharge Planning

Corticosteroid Course

• Total course typically lasts 5-10 days for outpatient "burst" therapy. 1, 2
• No tapering necessary for courses less than 10 days. 1

Discharge Criteria

• PEF ≥70% of predicted or personal best. 1
• Symptoms minimal or absent. 1
• Oxygen saturation stable on room air. 1
• Patient stable for 30-60 minutes after last bronchodilator dose. 1

Common Pitfalls to Avoid

• Do not underestimate severity: Patients, relatives, and doctors often underestimate severity due to failure to make objective measurements. 1
• Do not delay corticosteroids: Early administration may reduce hospitalization rates. 1, 5
• Do not delay intubation once deemed necessary: Should be performed semi-electively before respiratory arrest occurs. 1
• Monitor for impending respiratory failure: Inability to speak, altered mental status, intercostal retraction, worsening fatigue, PaCO2 ≥42 mmHg. 1, 3
• Regular SABA use (≥4 times daily) can reduce duration of action: This highlights need for proper controller therapy. 3