Single-isomer levalbuterol: A review of the acute data

Abstract

Levalbuterol, the pure (R)-isomer of racemic albuterol, is a new therapeutic option for patients with asthma. Racemic albuterol comprises a 50:50 mixture of (R)- and (S)-albuterol, with (R)-albuterol conferring all of the bronchodilator effects of the racemate. Numerous preclinical and in vitro studies have indicated that (S)-albuterol is not an inert isomer, but may have proinflammatory effects. Results from clinical trials in adults and children with asthma have demonstrated that 0.63 mg levalbuterol provides effective bronchodilation with lower b-mediated side effects compared with 2.5 mg racemic albuterol. In the emergency department, levalbuterol provided greater bronchodilation and significantly reduced hospital admissions compared with racemic albuterol. Recent studies have supported that levalbuterol use in acute settings may reduce the cost of asthma treatment by decreasing the total treatments and subsequent respiratory therapy resources. Levalbuterol provides heath care professionals with a safe, effective, and potentially cost-saving alternative to racemic albuterol for the treatment of patients with asthma.

Effects of Albuterol Isomers on the Contraction and Ca2+ Signaling of Small Airways in Mouse Lung Slices

“…However, frequent use can reduce the efficacy of racemic albuterol and may, in fact, exacerbate bronchial constriction (3,4). Several studies have compared (R)-albuterol and racemic albuterol, and have suggested that the use of the single (R)-enantiomer provided bronchodilator effects at a reduced doses and with fewer hospitalizations (5)(6)(7).…”

A preliminary comparison of levalbuterol and albuterol in prehospital care

“…The elimination half-life of dexalbuterol is more than 50% that of levalbuterol, and dexalbuterol is preferentially retained in pulmonary tissues, accumulating with regular use of the drug. Levalbuterol demonstrates no similar evidence of accumulation in the respiratory tree (4). Levalbuterol seems to decrease intracellular calcium concentrations, promoting smooth muscle relaxation, whereas dexalbuterol increases these concentrations (5,6).…”

“…Levalbuterol is 20 times more potent than dexalbuterol in enhancing mucociliary transport and particulate clearance within bronchial tissue (9). Nowak finds that the bronchoprotective and bronchodilatory effects of racemic albuterol are due exclusively to the levalbuterol isomer, whereas dexalbuterol displays proinflammatory effects and provides no therapeutic benefit (4).…”

Management of severe asthma exacerbation in children

“…[30] Comparing levalbuterol with racemic albuterol in children showed inconsistent results. Some studies [31][32][33] showed that levalbuterol provided greater bronchodilation and significantly reduced hospital admissions compared with racemic albuterol, while the others [34][35][36] showed similar efficacy and adverse effects. Further studies are needed before definitive recommendation of evalbuterol in severe cases.…”