Learning Center/Pharmacology/Levalbuterol

Levalbuterol

Xopenex

bronchodilator sabainhaled (SVN) · inhaled (MDI)Onset: 5–10 minutesDuration: 5–8 hours

Mechanism of Action

Pure R-enantiomer of racemic albuterol. Binds beta-2 receptors with greater affinity than the S-isomer. S-isomer (in racemic albuterol) may contribute to some adverse effects. Bronchodilation via cAMP-mediated smooth muscle relaxation.

Dosing

Adult

SVN: 0.63–1.25 mg q6–8h; acute: 1.25 mg q20 min × 3. MDI (Xopenex HFA): 2 puffs (45 mcg/puff) q4–6h

Pediatric

6–11 years: 0.31 mg SVN q6–8h; ≥12 years: adult dosing

Indications

Acute bronchospasm (asthma, COPD)
Alternative to albuterol in patients with significant tachycardia

Contraindications

Hypersensitivity to levalbuterol or albuterol

Side Effects

Less tachycardia than racemic albuterol (clinical benefit debated)
Tremor
Nervousness
Headache
Hypokalemia

Monitoring Parameters

Heart rate
SpO2
Serum potassium
Pulmonary function response

Drug Interactions

Beta-blockers (antagonism)
MAOIs (cardiovascular potentiation)
Loop diuretics (additive hypokalemia)

Clinical Pearls

Marketed as having fewer cardiovascular side effects than racemic albuterol — clinical evidence is mixed
Significantly more expensive than albuterol with comparable efficacy in most studies
May be preferred in patients with baseline tachycardia or cardiac disease
Equivalent bronchodilation at half the dose of racemic albuterol

Mnemonic

💡 Lev = Left (the R-isomer rotates light to the right, but it's the 'good half')

NBRC High-Yield

R-isomer of albuterol — same mechanism, potentially fewer cardiac side effects
Equivalent bronchodilation at lower dose than racemic albuterol
Clinical advantage over albuterol is debated
More expensive — not always preferred over albuterol

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