Oxitropium bromide is a novel anticholinergic bronchodilator agent. The purpose of this study was to compare the bronchodilating and cardiovascular effects of oxitropium (0.2 mg), fenoterol (0.4 mg), combined oxitropium and fenoterol (0.2 mg and 0.4 mg, respectively) over a 10-h test period. Fourteen patients with chronic obstructive pulmonary disease (COPD) (FEV1, 0.95 +/- 0.38L) were studied in a randomized, double-blind, placebo-controlled trial. Combined oxitropium and fenoterol produced significantly greater improvements in FEV1 over a time span of 15 min to 10 h and in the area under the time-FEV1 curve (AUC) than either oxitropium or fenoterol alone. The effects of oxitropium on both FEV1 and AUC values were similar to those of fenoterol. Oxitropium resulted in a greater increase in FEV1 than the placebo even after 10 h. In contrast; fenoterol produced a significant improvement in the FEV1 for only 15 min to 4 h. Oxitropium showed no adverse cardiovascular effects, whereas fenoterol was associated with an increased heart rate at 15 min and 1 h after the administration. We conclude that oxitropium bromide is an effective and safe bronchodilator for even elderly patients with COPD.