Effect of nebulized ipratropium bromide on lung function in nonallergic bronchial asthma

The present investigation was performed on 64 randomly chosen never-smoking patients, 40-60 years old, with nonallergic bronchial asthma with an average FEV1 of 69-73% of predicted, a positive methacholine test, a normal serum IgE level, and a negative RAST or skin test to common allergens and not receiving oral steroid treatment. Sensitive spirometric tests were used to evaluate the dose-response effect of inhalation of 0.08, 0.15 or 0.25 mg of ipratropium bromide. The drug caused bronchodilatation with a nearly linear dose-response relationship for static lung volumes, while the total lung capacity was unchanged after this inhalation. Airway resistance decreased and specific airway conductance increased after all doses. Ventilation and flows were better after doses of 0.15 and 0.25 mg than after 0.08 mg. The intrapulmonary gas distribution improved only after inhalation of 0.25 and 0.15 mg. The currently recommended dose of 0.08 mg seems to be suboptimal for dilatation of both small and large airways.