[A comparative trial of bronchodilator effects of fenoteral and sch 1000 in chronic bronchitis (author's transl)].

In a group of 20 patients with chronic bronchitis, bronchodilator effects of fenoterol (400 mug), SCH 1000 (40 mug), and their combination (fenoterol 400 mug msch 1000 40 mug) have been evaluated and compared by measuring total pulmonary capacity (CPT), intrthoracic gas volume (VGT), forced expiratory volume in one second (VEMS), specific airways resistance (SRva) and maximun expiratory flow at a lung volume for which the initial flow was 0.1 l/s (Vo.iv). Measurements have been made before and 30, 60, 120 and 180 min after administration of the drug. With each of the three drugs, the improvement of the five functional parameters is statistically significant at all time intervals. Changes in CPT, VGT, VEMS and SRva are not statistically different when using the different drugs, whereas the Vo.1v changes suggest a lesser bronchodilator effect of SCH 1000 than fenoterol (p less than 0.05 at 180 min), and especially than fenoterol-SCH 1000 combination (p less than 0.05 at all time intervals). The combination is lightly but not significantly better than fenoterol only. On account of these results and the very high tolerance for the two drugs, a new medication combining SCH 1000 and fenoterol is desirable. The authors emphasize the sensitivity of maximum expiratory flow measurements at low lung volumes for trials on bronchodilators and the necessity to consider the possible reduction in CPT for flows comparison at an identical absolute lung volume.