Exhaled nitric oxide variations during oral challenge with different NSAIDs in patients with aspirin-induced asthma

Background: Patients with aspirin induced asthma (AIA) experience varying degrees of adverse respiratory reactions after use of nonsteroidal anti-inflammatory drugs (NSAIDs). The effect of oral challenges with different NSAIDs on fractional exhaled nitric oxide(FeNO) as a marker of airway inflammation has notbeen thoroughly investigated. Objectives: To investigate the effect of oral challenges with 3 different NSAIDs, namely Aspirin (ASA), nimesulide (NIM) and celecoxib(CEL) on FeNO values in patients with AIA. Methods: Oral challenge with all 3 drugs was performed in 30 patients with AIA and 15 patients with Aspirin Tolerant Asthma (ATA), compared with 15 normal subjects. Results: Patients with AIA and ATA had baseline FeNO significantly higher than controls (26.06 ± 7.74 and 23.74 ± 3.27 vs. 9.55 ± 2.00 p.p.b. respectively, p<0.001). During Oral Challenge with Aspirin (OAC) FeNO levels increased significantly only in patients with AIA, starting to rise 45 minutes after the administration of the first dose (27 mg) of aspirin and reaching a peak value about 6 hours after the beginning of OAC ( 53.14 ± 15.07 p.p.b., vs26.06 ± 7.74 p<0.001). Statistically significant, although lower, increase in FeNO peak values was also observed only in patients with AIA during oral challenges with NIM and CEL (34.03 ± 11.3 p.p.b. vs 25,84 ±8,26 and 27.85 ± 8.98 p.p.b. vs 25,49 ± 8,23 respectively). Conclusion: FeNO seems to be a sensitive and early marker of inflammation in patients with AIA receiving NSAIDs. The safety of COX-2 inhibitors seems to be further supported by the minimal increase in FeNO.