Early bronchodilating effect of oxitropium bromide in comparison with ipratropium bromide

The bronchodilating effects of a metered aerosol dose of 40 micrograms ipratropium bromide and of 200 micrograms oxitropium bromide are similar 15 min. after administration. The bronc hodilating activity of ipratropium bromide appears earlier (i.e., 75-90 s after administration) than that of oxitropium bromide but later than that of ibuterol, a beta2-agonist. Ipratropium bromide administered at the close of 80 micrograms provokes a bronchodilation about double of that obtained with 40 micrograms. An adaptation of the usual dosage should be considered.