Antileukotriene agents in asthma: The dart that kills the elephant?

THE PERSISTENCE OF AIRWAY INFLAMMATION is believed to cause the mechanical changes and symptoms of asthma. After decades of research, a new class of m edication has emerged that focuses on leukotrienes, mediators of inflammati on. These substances are potent inducers of bronchoconstriction, increased vascular permeability and mucus production, and they potentiate the influx of inflammatory cells in the airways of patients with asthma. In this artic le the author reviews the development, mechanism of action, and clinical an d toxic effects of the leukotriene synthesis inhibitors and receptor antago nists that are entering the North American market. These agents can decreas e airway response to. antigen, airway hyperresponsiveness and exercise-indu ced asthma. They are also effective inhibitors of ASA-induced symptoms. Alt hough few published studies are available, the antileukotrienes seem almost as effective in the management of chronic asthma as low-dose inhaled corti costeroids, and their use permits a decrease in the frequency of use or dos e of corticosteroids. Further evaluation and clinical experience will deter mine the position of targeted inhibition of the leukotriene pathway in the treatment of asthma.