What are the recommended levosalbutamol (levosalbutamol) syrup dosages for adults (≥12 years), children 6–11 years, children 2–5 years, and infants (<2 years)?

Levosalbutamol Syrup Dosing

Levosalbutamol syrup is FDA-approved for children ≥2 years of age, but inhaled formulations (nebulizer or MDI with spacer) are strongly preferred over oral syrup because they deliver superior bronchodilation with markedly fewer systemic side effects such as tachycardia, tremor, and hypokalemia. 1

Critical Context: Oral Syrup Has Been Replaced by Inhaled Delivery

• Modern asthma guidelines have abandoned oral beta-agonists in favor of inhaled delivery because inhaled albuterol/levosalbutamol offers a superior therapeutic index—delivering effective bronchodilation with a markedly lower risk profile. 1
• Inhaled albuterol (nebulizer or MDI with spacer) delivers drug directly to the airways, producing faster onset of bronchodilation compared with oral syrup. 1
• Because systemic absorption is minimal with inhaled delivery, the incidence of tachycardia, tremor, and hypokalemia is markedly lower than with the oral route. 1

Age-Based Inhaled Levosalbutamol Dosing (Preferred Route)

Infants (<2 years)

• MDI with spacer + face mask: 1–2 puffs (≈90 µg/puff) every 4–6 hours as needed. 1
• For acute exacerbations: 4–8 puffs every 20 minutes for three doses, then every 1–4 hours as needed. 1
• Nebulized levosalbutamol: 0.31 mg/3 mL (half the dose of racemic albuterol) every 4–6 hours as needed. 1
• For acute exacerbations: 0.31 mg every 20 minutes for three doses, then every 1–4 hours as needed. 1

Children 2–5 years

• MDI with spacer + face mask: 1–2 puffs every 4–6 hours as needed. 1
• For acute exacerbations: 4–8 puffs every 20 minutes for three doses, then every 1–4 hours as needed. 1
• Nebulized levosalbutamol: 0.31 mg/3 mL every 4–6 hours as needed. 1
• For acute exacerbations: 0.31 mg every 20 minutes for three doses, then every 1–4 hours as needed. 1

Children 6–11 years

• MDI with spacer or nebulizer: 2 puffs every 4–6 hours as needed. 1
• Nebulized levosalbutamol: 0.31–0.63 mg every 4–6 hours as needed. 1
• For acute exacerbations: 4–8 puffs (MDI) or 0.63 mg (nebulizer) every 20 minutes for three doses, then every 1–4 hours as needed. 1

Adults and adolescents (≥12 years)

• MDI: 2 puffs every 4–6 hours as needed. 1
• Nebulized levosalbutamol: 0.63 mg every 4–6 hours as needed. 1
• For acute exacerbations: 0.63–1.25 mg every 20 minutes for three doses, then every 1–4 hours as needed. 1

Levosalbutamol Dosing Equivalence

• Levosalbutamol (R-albuterol) may be used at half the dose of racemic albuterol because it contains only the therapeutically active R-isomer. 1
• For children under 5 years, 0.31 mg/3 mL of levosalbutamol nebulizer solution is equivalent to 0.63 mg of racemic albuterol. 1
• Levosalbutamol binds to the beta2-adrenergic receptor with high affinity, whereas (S)-albuterol binds with 100-fold less affinity and may work in opposition to (R)-albuterol. 2

Administration Technique for Inhaled Delivery

• A spacer/holding chamber with face mask must be used when administering MDI treatments to children under 4 years; omission of the spacer or mask markedly reduces drug delivery to the lungs. 1
• Oxygen is the preferred gas source for nebulization at 6–8 L/min flow rate. 3
• Dilute levosalbutamol in 2–3 mL of saline solution for adequate nebulization. 3

Acute Exacerbation Protocol

• Initial emergency treatment: 0.31 mg (for children <5 years) or 0.63 mg (for children ≥5 years and adults) every 20 minutes for three doses. 1
• Maintenance after initial phase: repeat dose every 1–4 hours as needed, guided by clinical response. 3
• Add ipratropium bromide 0.25–0.5 mg to each nebulized dose every 20 minutes for the first three doses during severe exacerbations. 1

Monitoring and Safety

• Monitor heart rate, respiratory rate, oxygen saturation, and clinical response when administering levosalbutamol. 3
• Watch for tachycardia, tremor, hypokalemia, and hyperglycemia as potential side effects. 3
• Levosalbutamol was well tolerated in clinical trials and the risk/benefit ratio was reported to be superior to that of racemic salbutamol. 4

Clinical Efficacy Evidence

• Nebulized levosalbutamol is superior to racemic salbutamol in children in the treatment of acute exacerbation of asthma, with significant improvement in respiratory rate, heart rate, oxygen saturation, PEFR, and asthma score. 5
• Levosalbutamol 0.625 mg was at least as effective as racemic salbutamol 2.5 mg in providing relief from asthma symptoms. 4
• Racemic salbutamol causes significant tachycardia compared to levosalbutamol. 5

Common Pitfalls to Avoid

• Do not use oral syrup when inhaled formulations are available—this is outdated practice with inferior outcomes. 1
• Do not omit the spacer/mask in children under 4 years—this dramatically reduces drug delivery. 1
• Do not use levosalbutamol as monotherapy for long-term asthma control—it is a quick-relief medication only. 6
• Increasing use of levosalbutamol or use >2 days per week for symptom relief (not prevention of exercise-induced bronchospasm) indicates inadequate asthma control and the need for initiating or intensifying anti-inflammatory therapy. 6