From the Guidelines
Levosalbutamol, also known as levalbuterol, is a bronchodilator medication used to treat asthma, bronchospasm, and other respiratory conditions, and it is the R-enantiomer of salbutamol (albuterol). It works by selectively stimulating beta-2 receptors in the lungs, causing the smooth muscles in the airways to relax and widen, making breathing easier. The medication is typically administered via an inhaler or nebulizer, with common dosages being 45-90 mcg (inhaler) or 0.63-1.25 mg (nebulizer) every 4-6 hours as needed, as seen in the guidelines for managing asthma exacerbations 1. Some key points to consider when using levosalbutamol include:
- It is the purified form of the active component of regular albuterol, which means it may cause fewer side effects like tremors, nervousness, and increased heart rate in some patients because it lacks the S-enantiomer that contributes to these adverse effects but provides little bronchodilation benefit 1.
- The medication provides quick relief of symptoms, usually within minutes, making it valuable for acute breathing difficulties, though it doesn't treat the underlying inflammation causing asthma 1.
- Levosalbutamol administered in half the milligram dose of albuterol provides comparable efficacy and safety, as stated in the expert panel report 3 (EPR-3) guidelines for the diagnosis and management of asthma 1. The recommended dosage for levosalbutamol is 0.075 mg/kg (minimum dose 1.25 mg) every 20 minutes for 3 doses, then 0.075-0.15 mg/kg every 1-4 hours as needed for children, and 1.25-2.5 mg every 20 minutes for 3 doses, then 5 mg every 1-4 hours as needed for adults, according to the guidelines 1.
From the FDA Drug Label
The active component of XOPENEX HFA (levalbuterol tartrate) Inhalation Aerosol is levalbuterol tartrate, the (R)-enantiomer of albuterol. Levalbuterol tartrate is the generic name for (R)-albuterol tartrate in the United States. Levosalbutamol is another name for levalbuterol, which is the (R)-enantiomer of albuterol.
- It is a relatively selective beta2-adrenergic receptor agonist.
- The drug label does not provide further information on levosalbutamol beyond its identification as levalbuterol 2.
From the Research
Definition of Levosalbutamol
- Levosalbutamol, also known as levalbuterol, is a single isomer beta2-agonist that differs from racemic albuterol by elimination of (S)-albuterol 3, 4, 5, 6, 7.
- It is the therapeutically active isomer of salbutamol, a chiral drug with R (levosalbutamol) and S-isomers 7.
Mechanism of Action
- Levosalbutamol acts by stimulating the β2-adrenoceptor present on smooth muscle and other cells in the airways, resulting in bronchodilatation 3.
- It has a high affinity for the beta2-adrenergic receptor, whereas (S)-albuterol binds with 100-fold less affinity 4.
- Levosalbutamol possesses the bronchodilatory, bronchoprotective, and ciliary-stimulatory properties of racemic albuterol, while (S)-albuterol does not contribute beneficially to the therapeutic effects of the racemate 4, 5.
Therapeutic Use
- Levosalbutamol is indicated for the treatment or prevention of bronchospasm with reversible obstructive airway disease 3.
- It is used in the treatment of patients with asthma and chronic obstructive lung disease 4, 5, 6.
- Clinical trials have shown that levosalbutamol has therapeutic advantages over racemic salbutamol and is more cost-effective 7.
Comparison with Racemic Salbutamol
- Levosalbutamol provides greater bronchodilation than racemic albuterol and offers the possibility for improving clinical outcomes in patients with asthma and other obstructive airway diseases 4.
- It can be given at lower doses than racemic albuterol to provide comparable bronchodilation, with the potential for reduced beta-mediated adverse effects in adults and children 4, 6.
- The use of levosalbutamol may eliminate the persisting obstruction and decrease elastance that are associated with enhanced inflammation, allowing for more effective suppression of edema and diminution of leukocyte activation 5.