What is the first‑line rescue inhaler for acute bronchospasm in asthma and chronic obstructive pulmonary disease, and what is the recommended dosing?

First-Line Rescue Inhaler Options for Acute Bronchospasm

Short-acting inhaled β2-agonists (albuterol/salbutamol or terbutaline) are the first-line rescue inhalers for acute bronchospasm in both asthma and COPD, delivered via metered-dose inhaler with spacer or nebulizer. 1

Recommended Medications and Dosing

For Asthma

• Albuterol (salbutamol): 2.5–5 mg via nebulizer or 200–400 μg (2–4 puffs) via MDI with spacer 1, 2
• Terbutaline: 5–10 mg via nebulizer or 500–1000 μg via MDI 1
• Adding ipratropium bromide 500 μg provides additional benefit in acute asthma (Grade A evidence), making combination therapy superior to β-agonist alone 1

For COPD Exacerbations

• Albuterol (salbutamol): 2.5–5 mg via nebulizer or up to 1000 μg via MDI with spacer 1, 2
• Terbutaline: 5–10 mg via nebulizer 1, 2
• Ipratropium bromide can be added (250–500 μg) but provides no additional benefit in acute COPD exacerbations (Grade A evidence), unlike in asthma 1

Delivery Method Selection

MDIs with spacers are equally effective as nebulizers for bronchodilation (Grade A evidence) and should be the preferred first-line delivery method for most patients who can use them properly. 1, 2

When to Use MDI with Spacer:

• Patients with adequate technique and coordination 2
• Outpatient or stable inpatient settings 2
• More cost-effective and convenient for most patients 2

When to Use Nebulizer:

• Severely breathless patients who cannot coordinate MDI technique 1
• Acute exacerbations requiring high-frequency dosing 2, 3
• Patients requiring doses >1 mg albuterol or >160 μg ipratropium 2, 3
• Hospital settings where staff convenience is a factor 1

Dosing Frequency and Duration

• Initial treatment: May be repeated within minutes if suboptimal response, or given continuously until patient stabilizes 1, 2
• Maintenance during exacerbation: Every 4–6 hours until recovery 1, 2
• Transition to MDI: Switch from nebulizer to hand-held inhaler as soon as condition stabilizes, which may permit earlier hospital discharge 1, 2

Critical Safety Considerations

For COPD Patients:

• Never use oxygen to drive nebulizers in patients with CO2 retention and acidosis—always use compressed air with supplemental oxygen via nasal cannula if needed 2, 3
• Oxygen-driven nebulizers can worsen hypercapnia and respiratory failure 2, 3

Escalation Criteria:

• Lack of response to repeated nebulized therapy mandates senior clinician review and consideration of noninvasive ventilation or intensive care 1, 2

Key Distinctions Between Asthma and COPD

The most important clinical difference is that combination β-agonist plus anticholinergic therapy provides added benefit in acute asthma (Grade A) but NOT in acute COPD exacerbations (Grade A). 1, 2 This distinction is critical for appropriate prescribing—while ipratropium should be routinely added in acute asthma, it offers no additional bronchodilation beyond β-agonist alone in acute COPD. 1

Common Pitfalls to Avoid

• Do not prescribe home nebulizers without formal respiratory specialist assessment including demonstration of ≥15% improvement in peak flow over baseline 2
• Do not use intravenous methylxanthines—they are not recommended due to increased side effects without added benefit 1
• Do not continue nebulizer therapy once stable—transition to MDI within 24–48 hours to facilitate discharge 2, 3
• Verify proper inhaler technique before attributing treatment failure to medication inadequacy 2