New drug evaluation using exercise-induced bronchospasm.

Exercise-induced asthma was used to demonstrate that a xanthone, a new orally active cromolyn-like drug, has significant activity in man. The effect of a single oral dose of 8 mg/kg was studied in a double-blind corss-over fashion at two and five hours after administration, with significant inhibition of post-exercise bronchospasm being seen at five hours. Further study seems indicated to determine optimal dosage and clinical effectiveness.