Fractional Exhaled Nitric Oxide and Asthma Treatment Adherence

Purpose Of Review: Despite increased clinician awareness, nonadherence to inhaled corticosteroid treatment presents a major challenge to successful asthma management and risks inappropriate treatment escalation, particularly in severe disease. In patients with Type-2 mediated biology, fractional exhaled nitric oxide (FeNO) has a role in assessment and monitoring of adherence to inhaled corticosteroids.

Recent Findings: Asthmatic patients with elevated FeNO are at an increased risk of exacerbation. High FeNO is often secondary to suboptimal adherence to inhaled corticosteroid treatment, whether intentional or nonintentional. FENO-suppression can 'unmask' underlying adherence issues and is a useful test in the presence of Type-2 biology in the 'difficult-to-control' asthma population. Identification of nonadherence can improve asthma control and prevent inappropriate commencement of costly biologic therapies.

Summary: Assessment of adherence and FeNO response to monitored inhaled corticosteroid in Type-2 biomarker high asthmatic individuals may prevent unnecessary escalation to biologic therapy. Establishing an 'optimised' FeNO may alert clinicians to the possibility of underlying nonadherence at future clinical assessments.