The bronchodilator response to inhalation of increasing doses of aerosolized albuterol

Forty-four asthmatic patients were treated on separate days with increasing doses of albuterol in four double-blind studies that included placebo controls. Twenty-six subjects received one, two, four, six, and eight inhalations from a metered dose inhaler; 18 subjects received 1.25, 2.5, 5, 10, and 15 mg delivered by IPPB. There was a significant linear relationship in both groups between the maximum increase in FEV1 and the log dose of albuterol. The response to four, six, and eight inhalations from the metered dose inhaler was significantly greater than the response to one inhalation, and the response to 15 mg by IPPB was significantly greater than the response to any other dose by IPPB. The results suggest that in many patients maximum possible bronchodilation is not achieved by customarily recommended doses.