Does regular treatment with ketotifen inhibit bronchoconstriction induced by isocapnic hyperventilation?

Abstract
Eight asthmatic patients completed a 12‐week, double‐blind, placebo controlled study to assess the efficacy of ketotifen, 1 mg twice daily, in the inhibition of bronchoconstriction induced by isocapnic hyperventilation (IH). There was no significant difference in the degree of bronchoconstriction produced by IH after treatment with ketotifen or placebo.