Asthma - Inhaled Corticosteroids
According to the NHLBI guidelines, inhaled corticosteroids are the preferred first-line controller therapy for persistent asthma for all age groups. This recommendation is based on numerous studies demonstrating that inhaled corticosteroid treatment results in decreased asthma symptoms, decreased use of rescue bronchodilator, and decreased frequency of acute asthma symptoms.
The largest study demonstrating the benefit of inhaled corticosteroids in pediatric patients with asthma was the Childhood Asthma Management Program (CAMP), which showed that regular treatment with inhaled corticosteroids was superior to both nedocromil and placebo.
The subjects receiving inhaled corticosteroids experienced fewer hospitalizations and emergent care visits, decreased symptoms and use of albuterol rescue therapy, and fewer episodes of acute asthma requiring oral prednisone. Initiation of inhaled corticosteroids should be prompted when a patient demonstrates persistent asthma symptoms.
Based on the severity of symptoms, patients should initially receive low to moderate doses of inhaled corticosteroids and be monitored for response. If improvement in symptoms, lung function, and rescue bronchodilator use is seen, the dose should be maintained and then later decreased if tolerated.
If control is not obtained, then a trial of either a higher dose of inhaled corticosteroids or the addition of a second agent should be considered. Currently, the guidelines leave this decision to the clinician, but recent studies have shown that there is significant heterogeneity in response to medications by asthmatics.
In fact, a recent study demonstrated that, with increased inhaled corticosteroid dose and the addition of LABAs, only two thirds of the subjects gained control. Additionally, by recent studies have demonstrated the limitations of inhaled corticosteroids. For example, the PEAK study was unable to demonstrate asthma prevention.
In fact, no clear evidence thus far has shown that inhaled corticosteroid treatment alters the natural progression of asthma. Multiple preparations of inhaled corticosteroids exist, including nebulized hydrofluoroalkane (HFA) metered dose inhalers and dry powder inhalers. Dosing differs according to delivery device and steroid.
The most common side effects of inhaled corticosteroids are local and include hoarseness or dysphonia, cough, and oral candidiasis. The stringent use of mouth rinsing can dramatically reduce the likelihood of these symptoms, as does the use of a spacer device. When oral candidiasis occurs, it is easily managed with topical antifungal therapy.
Systemic side effects seen with inhaled corticosteroids are usually limited to patients receiving very high doses and are similar to the side effects seen with systemic corticosteroids: adrenal suppression, growth suppression, decreased bone density, myopathy, and weight gain.
Many parents express concern about the risk of growth suppression, and previous studies have shown that moderate doses of inhaled corticosteroids have a small but detectable effect on growth in the first year. This effect is much less with low doses and the long-term effect on adult height is virtually undetectable, but may be seen with higher doses.
This risk may be increased in patients who are concurrently treated with additional topical steroids for their skin or nasal mucosa. Despite this low risk, vigilance in following linear growth is still recommended for children on any dose of inhaled corticosteroids. Titration to the lowest effective dose of inhaled corticosteroids for optimal disease control minimizes the possibility of adverse side effects.