Exercise-induced wheeze: fraction of exhaled nitric oxide-directed management

Cowan, D. C. , Hewitt, R. S., Cowan, J. O., Palmay, R., Williamson, A., Lucas, S. J. E., Murrell, C. J., Thomas, K. N. and Taylor, D. R. (2010) Exercise-induced wheeze: fraction of exhaled nitric oxide-directed management. Respirology, 15(4), pp. 683-690. (doi: 10.1111/j.1440-1843.2010.01740.x) (PMID:20337988)

Abstract

Background and objective: Exercise-induced wheeze (EIW) is common. Several treatment options exist. Patients with low fraction of exhaled nitric oxide (FENO) are unlikely to be steroid-responsive and might benefit from non-steroidal therapies. We assessed: the efficacy of cromoglycate, formoterol and montelukast in patients with EIW and low FENO (<35 ppb) in a randomized cross-over trial, and the efficacy of inhaled corticosteroid in a high FENO (>35 ppb) group. Methods: Patients had EIW and airway hyperresponsiveness (AHR) to mannitol and/or exercise. Those with low FENO (n = 19) received cromoglycate (20 mg inh. bd + before challenge tests), formoterol (12 µg inh. Bd + before challenge tests) and montelukast (10 mg p.o. od), each for 2 weeks. Those with high FENO (n = 20) took inhaled fluticasone (500 µg) daily for 4 weeks. Primary end-points were: 50% reduction in maximum FEV1 %fall (clinical protection) and decrease in AHR to mannitol. Results: In patients with low FENO, cromoglycate, formoterol and montelukast significantly decreased AHR to mannitol in 63%, 61% and 47% of patients, respectively. In this group, the magnitude of exercise-induced bronchoconstriction (EIB) was significantly reduced with montelukast and formoterol; between-treatment differences were not significant. Of 6/19 with low FENO and EIB, protection occurred in 67% (cromoglycate), 83% (formoterol) and 50% (montelukast), respectively. In the high FENO group, AHR to mannitol and EIB decreased significantly with fluticasone (P < 0.001, P = 0.005, respectively), and protection occurred in 7/8 (88%) with EIB. Conclusions: In patients with EIW and low FENO, the number of ‘responders’ to cromoglycate, formoterol and montelukast was similar. In a high FENO population the response to inhaled corticosteroid was highly significant and comparable to previous studies.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Cowan, Douglas
• Authors: Cowan, D. C., Hewitt, R. S., Cowan, J. O., Palmay, R., Williamson, A., Lucas, S. J. E., Murrell, C. J., Thomas, K. N., and Taylor, D. R.
• College/School: College of Medical Veterinary and Life Sciences > School of Infection & Immunity
• Journal Name: Respirology
• Publisher: Wiley
• ISSN: 1323-7799
• ISSN (Online): 1440-1843