What is the recommended levosalbutamol dosing for acute bronchospasm relief and routine use in adults (≥12 years), including adjustments for patients over 65 years or with cardiac disease?

Levosalbutamol Dosing for Adults

For acute bronchospasm in adults (≥12 years), levosalbutamol 0.63-1.25 mg via nebulizer is the recommended dose, which provides equivalent bronchodilation to racemic salbutamol 2.5 mg. 1

Acute Bronchospasm Relief

Standard Dosing

• Initial dose: 0.63-1.25 mg levosalbutamol nebulized in 3 mL total volume 1
• This is equivalent to half the dose of racemic salbutamol (2.5 mg), since levosalbutamol contains only the active (R)-enantiomer 2, 3
• For severe exacerbations, use 1.25 mg levosalbutamol 1

Frequency in Acute Settings

• Every 20 minutes for first 3 doses if severe bronchospasm 1
• Then every 1-4 hours as needed if improving 1
• For moderate exacerbations: every 4-6 hours 1

Administration Details

• Dilute to minimum 3 mL total volume using normal saline 4
• Use oxygen at 6-8 L/min as driving gas when available 4
• Treatment takes 5-10 minutes; continue until 1 minute after "spluttering" occurs 1

Routine/Chronic Use

Maintenance Dosing

• 0.63 mg three times daily for routine asthma control 3
• This dose was shown to be at least as effective as racemic salbutamol 2.5 mg 3
• Higher dose of 1.25 mg three times daily may be used if needed 3

Special Populations

Patients Over 65 Years

• Use standard adult dosing (0.63-1.25 mg) 1
• First treatment should be supervised, as beta-agonists may rarely precipitate angina in elderly patients 1
• No specific dose reduction is required based on age alone 1

Patients with Cardiac Disease

• Cardiac disease is NOT a contraindication to levosalbutamol use 5
• Standard doses (0.63-1.25 mg) do not significantly affect heart rate 5
• Even 5-10 times the standard dose only increases heart rate by 20-30 beats/minute 5
• Salbutamol does not induce severe arrhythmias, even in patients with cardiac comorbidity 5
• Treatment should not be withheld in cases of tachycardia or underlying heart disease 5

When to Add Ipratropium

• Add ipratropium 500 μg to levosalbutamol if poor response to initial beta-agonist alone 1
• Combination can be mixed in the same nebulizer chamber 1, 4
• Use combined therapy for severe exacerbations or COPD patients 1

Important Clinical Considerations

Dosing Rationale

• Levosalbutamol contains only the therapeutically active (R)-enantiomer, eliminating the potentially harmful (S)-enantiomer found in racemic salbutamol 2, 3
• 100 μg levosalbutamol via MDI equals 200 μg racemic salbutamol in bronchodilator effect 2
• This 2:1 ratio applies to nebulized formulations as well 1, 3

Monitoring Parameters

• Peak flow rate, heart rate, respiratory rate, and oxygen saturation 4
• For chronic use, measure peak flows twice daily before nebulization, plus 30 minutes after morning treatment 1

Common Pitfall

• Do not use "dryness" as endpoint for nebulization—continue until 1 minute after spluttering begins 1
• Avoid undertreating severe exacerbations by using insufficient frequency in the first hour 1