RESUMEN
A multi-center, open, randomized, 2-way crossover study was conducted with chronic obstructive pulmonary disease (COPD) patients to compare the safety and efficacy of cumulative doses of ipratropium bromide administered from a pressurized metered-dose inhaler (MDI) or from a breath-activated dry powder inhaler (DPI). Enrolled in the study were 39 patients with moderate to severe COPD and who showed a > or= 15% increase in baseline forced expiratory volume in the first second (FEV(1)) after 80 microg of ipratropium bromide. Thirty-six patients were evaluable for efficacy analysis, and 38 patients were included in the safety analysis group. A significant improvement in pulmonary function was observed following inhalation of cumulative doses of ipratropium bromide (from 20 to 320 microg), but no statistically significant difference was found between the 2 formulations. The dose-response curves were similar. There was no statistical difference in area-under-the-curve during the 180 min period after the last dose for any of the pulmonary function variables. Overall, effects on pulse rate, blood pressure, and QT interval on electrocardiogram were no different between the devices. Six mild adverse events occurred in 4 patients: ventricular ectopic beats on electrocardiogram at 270 min with MDI, bad taste with both MDI and DPI, slight transient increase in blood pressure in the same patient during each study day with both MDI and DPI. Two moderate adverse events occurred in 2 patients: transient ventricular ectopic beats on electrocardiograms with DPI at 270 min, moderate bronchospasm with MDI at 200 min. Patients expressed a preference for DPI, which was found to have a better acceptability and appeared to be easier to use than MDI. The new lactose powder formulation of ipratropium bromide inhaled via the breath-activated DPI is a safe and effective alternative to the chlorofluorocarbon-propelled MDI.