In ten adult patients with severe, partially reversible airflow obstruction due to
asthma, with or without co-existent
chronic bronchitis, the acute
bronchodilator responses of
ipratropium bromide (40 micrograms) and
terbutaline (500 micrograms) from
metered-dose inhalers,
atropine methonitrate (2 mg) as a wet
aerosol and placebo were compared in a double blind trial. Also the combination of
ipratropium bromide and
terbutaline aerosols was compared with both
ipratropium and
terbutaline alone in short-term and long-term studies. In the short-term study, all the drugs produced significant bronchodilatation compared with placebo. The responses to
ipratropium bromide and
terbutaline alone were not significantly different. The combination of
ipratropium bromide with
terbutaline did not produce significantly greater changes in the FEV1, SGaw or static lung volume than
terbutaline alone.
Atropine methonitrate however, produced significantly greater changes of the airway conductance (SGaw) and static lung volumes (TLC and RV) but not FEV1, when compared to
ipratropium bromide. When administered over randomised periods of one month each there were no significant differences between the combination of
ipratropium bromide and
terbutaline and each
drug alone in daily airflometer recordings, daily symptom scores or fortnightly spirometry and clinical assessment. It is concluded that
ipratropium bromide, in the conventional dose of 40 microgramm by
metered-dose inhaler produces safe, effective bronchodilatation. Its effect, however, did not significantly augment that of the beta
adrenergic stimulant,
terbutaline and was less than that of
atropine methonitrate 2 mg by wet
aerosol.