Effect of nedocromil sodium on the bronchoconstrictor effect of neurokinin A in asthmatics.

In a double-blind, crossover study we have investigated the effect of nedocromil sodium on neurokinin A (NKA)-induced bronchoconstriction in asthmatics. 12 patients with mild asthma inhaled either nedocromil sodium 4mg or placebo, on 2 separate days, as 2 puffs from a metered-dose aerosol 30 minutes before challenge with NKA. On the placebo treatment day, NKA produced a concentration-dependent decrease in basal specific airway conductance (sGaw) and forced expiratory volume in 1 second (FEV1). The inhalation of nedocromil sodium 4mg inhibited the decrease in both sGaw and FEV1. The maximal percentage decrease in sGaw on the nedocromil sodium day was 27.0 +/- 5.2 (vs placebo, 53.3 +/- 5.4; p less than 0.05) and the maximal percentage decrease in FEV1 5.5 +/- 1.4 (vs placebo, 12.4 +/- 2.3; p less than 0.05). We conclude that nedocromil sodium protects against NKA-induced bronchoconstriction in asthmatics.