Tuesday, April 3, 2018

What's new in asthma treatment?

- Kenny Lin, MD, MPH

As part of the process of updating the 2007 National Asthma Education and Prevention Program (NAEPP) Expert Panel Report 3 guidelines, the Agency for Healthcare Research and Quality (AHRQ) recently released two comparative effectiveness reviews. The first AHRQ review concluded that subcutaneous and sublingual immunotherapy for patients with environmental allergies both reduce the use of long-term controller medications for asthma, and that sublingual immunotherapy also improves asthma symptoms and quality of life. A previous article in American Family Physician discussed allergen immunotherapy for family physicians who wish to offer this treatment in their offices or to determine whether a patient would be a candidate for therapy for an allergist.

The second AHRQ review evaluated the effectiveness of inhaled corticosteroids, long-acting beta agonists (LABA), and long-acting muscarinic antagonists (LAMA) for asthma in different patient populations. In children younger than age five with recurrent wheezing, the authors found that intermittent inhaled corticosteroid use during upper respiratory tract infections decreases asthma exacerbations. Another section of the review, which was published as a research article in JAMA, found that in patients with uncontrolled, persistent asthma, adding LAMA to inhaled corticosteroids reduced exacerbations compared to adding placebo, but had similar benefits compared to adding LABA. Finally, a third section concluded that in patients age 12 years and older, the use of combined inhaled corticosteroids and LABA as controller and quick relief therapy was associated with a lower risk of asthma exacerbations than more traditional strategies involving a controller therapy plus a short-acting beta agonist as relief therapy.

It remains to be seen how this new evidence will be incorporated into the next version of the NAEPP guidelines, which have historically advocated a stepwise approach to management of persistent asthma until good control is achieved. A shortcoming of the AHRQ reviews is that they did not specifically examine harms of LABA, the subject of a Medicine By the Numbers in the March 1 issue of AFP. A Cochrane review examined 48 trials that compared step therapy with an inhaled LABA/steroid combination to a higher inhaled steroid dose in more than 33,000 patients with asthma. Although 1 in 73 patients in the LABA/steroid group avoided a mild asthma exacerbation, there was no benefit on hospitalizations, deaths, or severe exacerbations. Moreover, the authors concluded that 1 in 1,430 additional persons in the LABA/steroid group would experience an asthma-related death, leading them to conclude that combination LABA/steroid inhalers have no benefits. Given the close balance of benefits and harms and uncertainty surrounding these estimates, family physicians should practice shared decision-making with patients about the pros and cons of controller medication options.

Dr. Jennifer Middleton summarized some useful tools and apps for asthma management in a previous Community Blog post, and you can find more information on the diagnosis, prevention, and treatment of asthma in our AFP By Topic collection.