"After spending half an hour convincing her of the benefits and safety of inhaled corticosteroids, she agreed. I saw him back 6 weeks later. His cough was pretty much gone, his lung function was completely normalized, and his FeNO had fallen 90%. That’s my record: A 90% reduction is about as good as it gets," Dr. Spahn said.
Assessing steroid adherence
Placing an allergic asthma patient on inhaled corticosteroid therapy should result in at least a 50% reduction in an elevated baseline FeNO. A lesser response, or an increasing FeNO during follow-up visits, is an indicator of an adherence problem.
"I like to tell people who’ve been in practice 20 years or longer that FeNO is to inhaled steroids as the theophylline blood level was to theophylline therapy. Back in the day when we used theophylline, our measure of adherence was checking someone’s theophylline level. If it was low and the patient was poorly controlled, we could blame their poor control on their poor adherence to theophylline. Up until FeNO, we didn’t have that ability with inhaled steroids. We can’t measure inhaled steroid levels due to the fact that they’re so small in the bloodstream," Dr. Spahn explained.
He reported receiving honoraria from GlaxoSmithKline as well as from Aerocrine, which markets an FeNO analyzer.