Adenosine-induced bronchoconstriction: comparison between nedocromil sodium and sodium cromoglycate

The purpose of this study was to compare the protective effect of nedocromil sodium with that of sodium cromoglycate against adenosine-induced bronchoconstriction in 15 asymptomatic asthmatic patients. Airways response was evaluated as FEV1 and adenosine was administered as an aerosol diluted in 0.9% saline to produce a concentration range of 0.03-4.00 mg/ml. When FEV1 was decreased by 20% of the post-saline value, inhalation was discontinued and the PD20 adenosine calculated. Patients were studied on four separate days. On the first day the adenosine challenge was performed and on subsequent days patients were pretreated with either placebo or test drug in a randomized double-blind manner. In this study both sodium cromoglycate and nedocromil sodium showed a significant protective effect against adenosine in comparison with placebo. Their activity was not related to a bronchodilator action. Nedocromil sodium showed a greater protective effect against adenosine challenge which may be indicative of a broader spectrum of activity against nonantigenic stimuli.