Bronchodilatory effect of trapidil in man.

Trapidil (Rocornal) is clinically used as a coronary vasodilator and inhibitor of coagulation of the platelet. Recently trapidil has been reported to have a bronchodilatory action in excised dog's tracheal smooth muscle. In the present study the bronchodilatory effects of trapidil were investigated in man. For 21 patients with asthma, 6 patients with emphysema and 2 patients with chronic bronchitis, 100 mg of trapidil was infused intravenously. Subjects were divided into two groups. Group I was infused for about 30 min and Group II for about 10 min. After administration of trapidil, forced vital capacity increased in both groups (p less than 0.01), forced expiratory volume at 1.0 s (p less than 0.01) and peak expiratory flow rate (p less than 0.05) increased in Group II. Respiratory resistance decreased (p less than 0.01) in Group II. From these results, it was confirmed that trapidil has bronchodilatory effect. We think trapidil is useful for the treatment of the patients not only with ischemic heart disease but with chronic obstructive lung disease.