Albuterol and isoproterenol in bronchial asthma. Efficacy and toxicity of drugs administered via intermittent positive pressure breathing.

This study compared the efficacy and side effects of 1.25, 2.5, 5, 10, and 15 mg of albuterol and isoproterenol hydrochloride administered by intermittent positive pressure breathing (IPPB) to 12 patients with reversible airway obstruction. Equal doses of the two medications induced similar peak increases in pulmonary function, but the increase following albuterol persisted longer. The degree of bronchodilation was impressive; 15 mg of albuterol induced a mean increase over six hours of 82% in the forced expiratory volume in one second. Significant cardiovascular side effects were more common after isoproterenol than after albuterol. Albuterol is superior to isoproterenol as a bronchodilator when administered by IPPB because, for a given peak bronchodilation, cardiovascular side effects are fewer and bronchodilation persists longer with albuterol. The optimal dose of isoproterenol hydrochloride is 2.5 to 5.0 mg and the optimal dose of albuterol is 10 mg when these drugs are given by IPPB.