Current standard management of an acute asthma attack calls for use of an aerosolized beta₂ agonist, generally in a dosage of 2.5 mg of albuterol given every 20 minutes for one hour. However, the assumption that this dosage is optimal for terminating an attack has never been rigorously tested. McFadden and associates conducted a prospective study to compare the effectiveness of a 5.0-mg dose of albuterol given twice during a 40-minute period with the standard 2.5-mg dose given three times during a 60-minute period in patients with acute exacerbations of asthma.

Adult patients with asthma who presented to an emergency department with an acute exacerbation of asthma were included in the study. Medical history, symptoms and medication use were recorded, peak expiratory flow (PEF) was measured and pulse oximetry was performed. One group of patients received 2.5 mg of aerosolized albuterol every 20 minutes for one hour. The other group received 5.0 mg of aerosolized albuterol every 20 minutes for two doses. Peak expiratory flow was measured after each treatment. Length of stay in the emergency department, clinical resolution and improvements in pulmonary function were assessed.

Eighty patients received the standard dosage of albuterol and 80 patients received the high dosage. Mean pretreatment PEF was less than 40 percent of normal at baseline. Patients receiving the high dosage (two doses of 5.0 mg) of albuterol had significantly more improvement in mean PEF after each treatment. These patients were well enough to be discharged from the emergency department after just one treatment more often than the patients receiving the standard dosage. Recurrence rates were similar in the two groups, with three patients in the standard-dosage group and four patients in the high-dosage group requiring additional treatment within 24 hours of discharge from the emergency department. Charges to third-party payers were 24 percent lower for patients who received the high-dosage therapy.

The authors conclude that the use of two 5.0-mg doses of aerosolized albuterol is as effective as the standard regimen of three 2.5-mg doses and has the advantage of more rapid improvement in lung function and more rapid discharge from the emergency department. A patient who fails to respond to 5.0 mg of albuterol with an increase in PEF to at least 40 to 45 percent of predicted levels should be hospitalized.