Nowak R, Emerman C, Hanrahan JP, et al (XOPONEX Acute Severe Asthma Study Group): A comparison of levalbuterol with racemic albuterol in the treatment of acute severe asthma exacerbations in adults. American Journal of Emergency Medicine. 24(3):259 267, 2006.
Standard racemic albuterol used for the treatment of respiratory distress from asthma and COPD contains equals amounts of the two forms (or isomers) of the albuterol molecule the S-isomer and the R-isomer. Some data suggests that the S-isomer may actually worsen constriction and cause inflammation, whereas the R-isomer possesses greater bronchodilatory and bronchoprotective properties.
This large, multi-center, randomized, double-blinded clinical trial compared the clinical improvement, hospital admission rates and time to ED discharge for asthma patients who received racemic (S- and R-isomer) albuterol versus those who received levalbuterol (the R-isomer). All patients were given corticosteroids along with the bronchodilators.
The study found that although clinical improvement was significantly higher in the levalbuterol group, hospitalization rates and time to ED discharge were the same for both groups. However, for those patients not on steroid therapy at the time of their attack, levalbuterol (the R-isomer) significantly reduced admission.
This very well-done study supports at least for asthma patients not on corticosteroids at the time of their asthma attack the use of levalbuterol (marketed as Xoponex). However, Xoponex costs somewhere between two and six times that of racemic albuterol. Although this cost increase would be offset by a reduction in overall hospitalizations, it s unclear whether its routine use as the first-line agent in prehospital care would be worth the additional cost incurred by the EMS agency.
Corresponding studies involving COPD patients and pediatrics demonstrate greater clinical improvement with levalbuterol, but again the added cost of the agent must be seriously considered when making the decision to add it to your inventory of medications.
One thing was made clear by this study: Early administration of corticosteroids to asthma patients, particularly those not currently taking them, significantly improves their clinical response, shortens their hospital stay and reduces their need for re-admission following their attack.