Influence on non-specific bronchial hyperreactivity to cold air hyperventilation and carbachol by nedrocromil and budenoside

In a double blind crossover trial we compared the effect of a four week treatment with inhaled nedocromil (4 x 4 mg/d) or budesonide (2 x 400 μg/d by spacer) on non-specific bronchial hyperresponsiveness (BHR) to cold air hyperventilation (CHV) and carbachol. 15 persons with clinically mild asthma, who showed a more than 50% decrease in sG(aw) after CHV were randomly allocated to treatment groups. A double dummy technique was applied. Before and after both treatment periods, which were seperated by an out wash period of four weeks, BHR to isocapnic cold air hyperventilation and carbachol was determined on two consecutive days. 13 persons completed the study. Maximum percentual drop of sG(aw)- and FEV1-values after CHV, the number of steps of carbachol-provocation carried out to reach a decrease in sG(aw) of at least 50% and the calculated cumulative breath units (CBU) of carbachol to cause a 50% (20%) decrease in sG(aw) (FEV1) were assessed. Peak-flow values were registered throughout the study. Data were compared by means of Wilcoxon's matched-pairs signed-ranks test. After budesonide most parameter showed a significant decrease of BHR (CHV: sG(aw) p < 0.1; FEV1 p < 0.05; Carbachol: provocatin-steps: p < 0.05; CBU: PD50 sG(aw) p < 0.05; PD20 FEV1 p < 0.05). There was no evidence for an influence of nedocromil on BHR (p-values all > 0.2). Comparing both treatments there was a difference in favour of budesonide partly reaching significance at 5% level. Budesonide but not nedocromil treatment showed a significant increase in peak-flow values (morning p < 0.02, evening p < 0.005). These results indicate that long term treatment with budesonide can diminish BHR to cold air hyperventilation. They cannot confirm a decrease of non-specific BHR after long term treatment with nedocromil. In the dosage applied treatment with budesonide is superior to nedocromil regarding effects on non-specific BHR.