title: The effect of inhaled RS 7540, a xanthone, on exercise-induced asthma.
abstract: The effect of 71 oxo-7-thiomethoxyxanthone-2-carboxylic acid sodium salt (RS 7540) in inhibiting exercise-induced asthma was compared with that of placebo in a double-blind crossover study. Single doses of 40 mg were given by inhalation to 12 patients. Ten of these subsequently received a dose of 20 mg. RS 7540 at both dose levels had a statistically significant effect in giving total or partial protection from exercise-induced bronchospasm; however, no dose relationship was apparent.
mesh_terms: D000328:Adult; D001249:Asthma / Q000188:drug therapy*; D001794:Blood Pressure; D001986:Bronchial Spasm / Q000188:drug therapy* / Q000209:etiology; D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D004341:Drug Evaluation; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D010366:Peak Expiratory Flow Rate; D005082:Physical Exertion; D010919:Placebos; D012138:Respiratory Therapy; D014966:Xanthenes / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D010919:Placebos; D014966:Xanthenes