Effect of nedocromil sodium on the late asthmatic reaction to bronchial antigen challenge.

The effect of inhaled nedocromil sodium (4 mg by pressurized aerosol) on the dual asthmatic reaction to bronchial antigen challenge was studied in eight patients with asthma. The following prechallenge/postchallenge treatment combinations were administered: nedocromil sodium/placebo, nedocromil sodium/nedocromil sodium, placebo/nedocromil sodium, and placebo/placebo. Each patient received three treatment combinations assigned with a balanced incomplete block design. Nedocromil sodium administered before antigen challenge was significantly more effective than placebo in blocking both the early (p less than 0.001) and late (p less than 0.01) fall in FEV1. Postchallenge administration of nedocromil sodium tended to delay the onset of late asthmatic reaction but did not provide significant protection compared to placebo. These results demonstrated that nedocromil sodium prevents both phases of the dual asthmatic reaction to bronchial antigen provocation when it is inhaled before challenge. Further investigation is necessary to elicit a definite answer to whether nedocromil sodium administered after bronchial challenge has an effect on late asthmatic reaction.