Nitric Oxide: A Potential Marker for Adherence in Asthma?

MARCH 21, 2018
Connor Walker, PharmD Candidate
Current treatment options for patients living with asthma include long acting beta-agonists and inhaled corticoid steroids (ICS). While these therapeutic options are effective in a majority of patients, approximately 10% will remain poorly controlled. This can be due to poor inhaler technique, poor medication adherence, and other comorbidities.

It can be difficult for providers to determine the cause of treatment failure, especially when it pertains to improper technique and medication adherence. A case study published December 2017 in the Journal of Asthma highlights the importance of proper medication adherence in addition to 1 possible marker that clinicians can use to track adherence.

Nitric oxide is a key component in all aspects of lung function and is often implicated in asthma’s pathophysiology. The American Thoracic Society states that persistently high fractional exhaled nitric oxide (FeNO) may be caused by poor adherence to ICS therapy. These findings may indicate FeNO as a potential marker to help track ICS adherence.

The patient in this case study received a device used to monitor her adherence and inhaler technique over a 3-month period. Clinicians monitored her FeNO levels at baseline, 4, 8 and 12 weeks. Handheld FeNO devices are now commercially available, reimbursable by some insurance providers, and can be used in clinical settings.

Results of this study include a reduction of FeNO from 92 ppb at baseline to 22 ppb at 12 weeks, along with an overall decrease in airway inflammation. This demonstrates that an increase in ICS use correlates inversely with a reduction of FeNO levels.

During the 12-week period, this patient reported no asthma exacerbations and effectively weaned her maintenance steroid dose down from 40 mg to 10 mg. The patient also reported that she was able to complete a 6-km run for the first time in many years.

Providers should look at these results and remember just how imperative it is that patients are educated on the importance of technique and medication adherence. Providers should also keep in mind that these topics may need to be reinforced multiple times with patients in order to ensure the best outcomes.

Connor Walker is a 2018 PharmD Candidate at the University of Connecticut.


 Hunt E, Flynn D, MacHale E, et al. Reduction in exhaled nitric oxide tracks improved patient inhaler compliance in difficult asthma-a case study. J Asthma. 2017;26:1-3.