Sch 1000: a New Anticholinergic Bronchodilator

Sch 1000 is a derivative of atropine with equivalent bronchodilator activity. A double blind controlled study of Sch 1000 administered to asthmatic subjects by inhalation in 4 doses from 10 mug to 80 mug was conducted. The onset of action was between 15 and 30 min, compared to 5 min for isoproterenol, but persisted for 4 hours compared to 1 hour for isoproterenol. The maximal level of bronchodilatation produced by Sch 1000 was comparable to but not as great as that after isoproterenol. Dose-response data suggested that maximal bronchodilatation may be achieved by 10 to 20 mug of Sch 1000; larger doses did not result in significantly greater increases in forced expiratory volume in 1 sec or maximal mid-expiratory flow. The Sch 1000-mediated increase in maximal mid-expiratory flow was significantly greater than that of forced expiratory volume in 1 sec. Fewer side effects were encountered after Sch 1000 than after isoproterenol and no atropine-like effects could be attributed to Sch 1000 in the doses studied.