Levosalbutamol Oral Dosing in Adults
Levosalbutamol is not available or recommended in oral formulation for adults; it is only approved and available as an inhaled nebulizer solution or metered-dose inhaler (MDI).
Available Formulations and Routes
- Levosalbutamol (levalbuterol) is exclusively available as an inhalation solution for nebulization and as a pressurized metered-dose inhaler (pMDI) 1, 2
- The drug was introduced in 1999 specifically as an inhaled formulation to provide the bronchodilatory benefits of the (R)-enantiomer of albuterol without the potentially adverse effects of the (S)-enantiomer present in racemic albuterol 1
- No oral tablet or syrup formulation of levosalbutamol exists or has been approved by regulatory authorities 1, 2
Standard Adult Dosing for Inhaled Levosalbutamol
Nebulizer Solution Dosing:
- Acute exacerbations: 1.25 mg every 20 minutes for 3 doses initially, then 1.25 mg every 1-4 hours as needed 3
- Maintenance therapy: 0.63 mg to 1.25 mg three times daily 2
- Levosalbutamol is administered at half the milligram dose of racemic albuterol for comparable efficacy (i.e., 1.25 mg levosalbutamol ≈ 2.5 mg racemic albuterol) 2, 4
Metered-Dose Inhaler Dosing:
- Standard dose: 100 mcg (2 puffs of 45 mcg each) every 4-6 hours as needed 5, 4
- This provides equivalent bronchodilation to 200 mcg of racemic albuterol 4
Clinical Context and Rationale
- The inhaled route is strongly preferred for all short-acting beta-2 agonists because it provides faster onset of action, greater bronchodilator effect, and significantly fewer systemic side effects compared to oral administration 5
- Levosalbutamol was specifically developed as an inhaled formulation to maximize therapeutic benefit while minimizing beta-mediated adverse effects such as tachycardia, tremor, and hypokalemia 1, 6
- In hospitalized patients, levosalbutamol 1.25 mg every 6-8 hours required fewer total nebulizations compared to racemic albuterol 2.5 mg every 1-4 hours, with similar efficacy and hospital costs 3
Important Clinical Considerations
- If oral bronchodilator therapy is specifically required (which is rare in modern practice), only racemic albuterol/salbutamol is available in oral formulations (tablets and syrup) 5
- Regular use of any short-acting beta-agonist exceeding twice weekly for symptom control indicates poor asthma control and necessitates initiation or escalation of controller medications 5
- The technology to separate stereoisomers only became available in the past decade, which is why levosalbutamol was developed relatively recently and exclusively as an inhaled product 1