Controlled trial of bronchodilator-mucolytic aerosols, combined and separate

In seven of 30 ambulatory asthmatics the inhalation of 10% acetylcysteine reduced the FEV1 by more than 10% (range: 14% to 53%). Inclusion of isoproterenol (0.05%) reversed this depression over the entire trial in six of these subjects, while the seventh responded similarly except for the last measurement. It is concluded that the addition of isoproterenol to an acetylcysteine aerosol in the above ratio can eliminate the ventilatory impairment induced by the latter and is therefore indicated for those patients with chronic obstructive lung disease who benefit from a mucolytic agent.