Dose-response of Albuterol in Asthmatics
Dose-response of Albuterol in Asthmatics
The purpose of this study was to determine the lung function response after increasing doses
 of albuterol (a bronchodilator) in children and adults with asthma.
Inhaled short-acting b2-agonists (SABA) are the most potent bronchodilators used today to
 treat acute symptoms of asthma and albuterol, a partial b2-agonist, is the most frequently
 prescribed asthma medication in the US. Although universally used in for acute asthma
 symptoms, SABA have been associated with a significant degree of interpatient variability.
 Many studies have characterized the SABA dose to bronchodilator response relationship under
 controlled conditions. However, few studies have explored the magnitude and sources of
 bronchodilator response variability, and no studies have characterized the dose versus
 bronchodilator response relationship using population pharmacokinetic/pharmacodynamic
 (PPK/PD) modeling. In the present study, we characterized the relationship between inhaled
 doses of albuterol and bronchodilation in 81 children and adults with moderate to severe
 persistent asthma using a population pharmacodynamic approach. The purpose of this study was
 to obtain estimates of the pharmacodynamic parameters that characterize the dose-response
 curve, including maximal dose for bronchodilation, and to quantify and identify sources of
 interpatient pharmacodynamic variability.
Eligibility Criteria:

 -  Well-defined history of physician diagnosed asthma

 -  Any ethnic background

 -  8 to 65 years old

 -  Baseline pre-bronchodilator FEV1 of 40% to 80% predicted for age, height, and gender

 -  No oral corticosteroid use, emergency room visits, or hospitalizations within the
 previous 3 months

 -  Nonsmokers or less than a 5 pack-year history with no smoking in the previous year

 -  Normal physical exam and no confounding diseases were selected

 -  Able to withhold inhaled short-acting b2-agonists or inhaled anticholinergic drugs for
 8 hours, oral antihistamines for 5 days, theophylline for 24 hours, and cromolyn,
 nedocromil, and inhaled corticosteroids for 2 hours prior to the study.