Inhaled corticosteroid therapy suppresses nitric oxide levels (NO) of airway origin but not necessarily NO of alveolar or small airway origin. Systemic therapy with an oral anti-leukotriene agent may suppress NO production in distal airways and alveoli not reached by inhaled therapy.
Asthma and Airway Centre, University Health Network, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada. leandro.fritscher@uhn.on.ca
