Summary

 Background: Nedocromil sodium confers both acute and chronic protective effects in patients with bronchial asthma, the interactions of which are unknown.

Objective: To examine to what extent and for how long nedocromil sodium prevents exercise-induced asthma when given immediately before exertion compared to chronic administration.

Patients and Methods: Eighteen asthmatic patients were given 4 mg NS at 30 min or 3.5 hours before exertion. We compared the resultant effect with that of the same protocol measured after 2 and 4 weeks of continuous treatment with the drug.

Results: Nedocromil sodium decreased exercise-induced asthma similarly at both points when given acutely. Chronic treatment of up to 4 weeks did not improve this protective effect at either interval following the inhalation.

Conclusion: Nedocromil sodium most likely reaches its maximal effect on exercise-induced asthma upon the first administration, although treatment for longer than 4 weeks might be required to prove a chronic effect of the drug.