The reducing effects of tazifylline on histamine-induced bronchoconstriction in atopic asthmatics

Percentage reductions in the peak flow rates to a standardized number of histamine inhalations were compared after 7 days of treatment with 10 mg bd tazifylline and after 7 days of placebo in a randomized crossover study in 11 male seasonal atopic asthmatics. After tazifylline, mean % reductions in peak flow rates were significantly lower than after placebo (p = 0.03). The effects of tazifylline had disappeared within 7 days of stopping treatment. Using a 50% decrease in bronchial reactivity as the criteria of "protection", 7 of the subjects were "protected" by tazifylline only and none by placebo only (p = 0.03).