Role of leukotriene receptor antagonists in pediatric asthma

During the past decade, the inflammatory mechanisms that result in the clinical syndrome we call asthma have been emphasized in research, publications, and the various asthma management guidelines. This information clearly emphasizes the treatment of asthma with maintenance controller therapies early after the onset of symptoms in all but the very mildest of patients. Until the advent of the leukotriene receptor antagonists, nearly all of these maintenance therapies needed to be administered by inhalation through a variety of devices and spacers. Inhalation of medication was necessary to either increase the amount of drug reaching the airways or to increase the therapeutic index of drugs such as corticosteroids. Even under the best circumstances, this route of administration is difficult and expensive for many parents whose children have asthma. Now that oral controller therapies (leukotriene receptor antagonists) are available for children, their role in clinical practice needs to be examined. The latest asthma management guidelines classify asthma into four groups of severity, and base treatment recommendations on the intensity of symptoms, need for rescue medications, and pulmonary function as measured by peak expiratory flow and forced expiratory volume in 1 sec (FEV(1)). The categories of mild intermittent, mild persistent, moderate persistent, and severe asthma in children will be addressed in this presentation by reviewing the available data on the use of the leukotriene receptor antagonist montelukast in children. Mild intermittent asthma can be typified by exercise-induced asthma, a common pediatric condition. In this often troublesome condition, montelukast demonstrated effectiveness at the end of a once a day dose by blocking the effects of this naturally occurring challenge. Drug regulatory approval of a new drug also includes patients with more regular symptoms who are usually classified as having persistent or moderate asthma. In these montelukast pediatric studies, approximately 40% of patients were already taking inhaled corticosteroids. Patients had improvements in FEV(1), symptoms, and rescue medication use, clearly showing an effect with once a day dosing. Pediatric data in severe asthma patients are more limited, but in such patients a therapeutic trial of montelukast would seem preferable to using systemic corticosteroids or increasing inhaled steroids to a level where adverse effects have an increasing potential of occurring. Montelukast has been available in the United States since March 1998 and has received excellent acceptance by physicians, parents, and patients. The 5-mg chewable tablet administered once a day in the evening in children aged 6-14 years apparently fills a previously unmet need in the treatment of pediatric asthma.