• To determine the most effective dose of inhalation arformoterol for treating acute bronchospasm in asthmatics by evaluating the averaged mean percent change from baseline % predicted FEV1 after 3 doses of study medication in each of the 3 groups [ Time Frame: 1 hour ] [ Designated as safety issue: No ]
  

• To determine the safety and tolerability of arformoterol when used to treat acute exacerbations of asthma. [ Time Frame: 5 hours ] [ Designated as safety issue: Yes ]
  
• The averaged mean percent change from baseline FEV1 and PEFR (percent predicted and absolute) after the 3 doses of study drug [ Time Frame: 1 hour ] [ Designated as safety issue: No ]
  
• The mean percent change from baseline in the FEV1 and PEFR (absolute and percent predicted) following each dose of study drug [ Time Frame: 1 hour ] [ Designated as safety issue: No ]
  
• The mean change from baseline in the FEV1 and PEFR (absolute and percent predicted) following each dose of study drug [ Time Frame: 1 hour ] [ Designated as safety issue: No ]
  
• The peak change (liters) and peak percent change from baseline in the FEV1 and PEFR (absolute and percent predicted) following each dose of study drug [ Time Frame: 1 hour ] [ Designated as safety issue: No ]
  
• The time to onset of a 15% improvement in FEV1 for each dose (individual and cumulative) and total dose of study medication to reach this [ Time Frame: 5 hour ] [ Designated as safety issue: No ]
  
• The time required to achieve a FEV1 and PEFR > 60% predicted for each dose (individual and cumulative) [ Time Frame: 5 hours ] [ Designated as safety issue: No ]
  
• Percent of responders (defined as those discharged following treatment who did not require additional therapy in the ED) [ Time Frame: 5 hours ] [ Designated as safety issue: No ]
  
• Percent of patients in each group requiring additional therapies after the first hour of study drug treatments [ Time Frame: 5 hours ] [ Designated as safety issue: No ]
  
• All of the primary and secondary endpoints partitioned by the presenting PFT in quartiles and the presenting S albuterol levels in quartiles [ Time Frame: 5 hours ] [ Designated as safety issue: No ]
  
• Determine the pharmacokinetics of arformoterol in this clinical setting [ Time Frame: 5 hours ] [ Designated as safety issue: No ]
  

Acute bronchospasm associated with exacerbations of asthma is a common problem. Currently the mainstay of treatment is inhalation albuterol, either levalbuterol or racemic mixture, in repetitive fashion depending on the resolution of the airways obstruction. Formoterol is a long-acting (>12 hours) selective beta2-agonist that has a very rapid onset of bronchodilatation (<3 minutes and thus similar to that produced by albuterol). Patients with acute bronchospasm could benefit from the prn use of formoterol as they would receive acute relief of their symptoms and this would last for a prolonged time period. Additionally formoterol has been reported to be 28-109 times as potent as albuterol and safe at doses of 54ug in healthy subjects and asthmatics. Racemic formoterol structurally has 2 chiral centers and thus is composed of 4 enantiomers. The RR form (or arformoterol) is the active bronchodilator and it is not clear what the physiologic actions of the other 3 enantiomers are. This study is the first to evaluate nebulized arformoterol solution for therapy of acute asthmatics presenting to the Emergency Department.