Acute Relief of Exercise-Induced Bronchoconstriction by Inhaled Formoterol in Children With Persistent Asthma: Conclusion
The primary outcome parameter, FEV1 at 5 min, showed no difference between formoterol and terbutaline. At 5 min after dosing, the mean increase from each predrug baseline was 62% of the maximum increase for each drug. The median recovery times for for-moterol, terbutaline, and placebo were 5.0 min, 7.4 min, and 44 min, respectively. Similar numbers of standard dose inhalations of formoterol (4.5 ^g) and terbutaline (0.5 mg) gave less systemic activity from formoterol.
EIB is a cardinal symptom in pediatric asthma affecting social and physical development and quality of life more so than in adults. Asthma management strategies today generally recommend the use of SABAs 15 min before exercise. This may be well suited for the scheduled activities of adult life, but it is insufficient for most children. Typically, children exercise spontaneously multiple times during a day, and such repeated pretreatment is a challenge to compliance. Prolonged protection should be preferred to enhance the child’s physical activity.
However, regular use of an LABA could induce tolerance with cross-tolerance to bronchodilators used as rescue treatment. The induced tolerance reduces the advantage of prolonged protection against EIB. Indeed, it is advised not to use regular LABAs as monotherapy, and the available evidence does not show convincing additive clinical effect or protection against exacerbations from regular LABAs added to ICS. However, intermittent use of formot-erol would be less prone to the development of tolerance and takes full advantage of the effect of the adrenergic symptom relief. This will provide the child with a rapid relief and long-term protection against EIB on occasions where the primary antiinflammatory control has failed to protect the child. This approach may eventually prove more successful for the management of childhood asthma than current options for relief.
In conclusion, this study shows a similar acute bronchodilatory effect from formoterol and terbutal-ine during EIB in children with persistent asthma. This proposes the usefulness of formoterol for relief therapy in pediatric asthma management.