The use of 5-lipoxygenase inhibitors and leukotriene receptor antagonists in the treatment of chronic asthma.

With the elucidation of asthma as a chronic inflammatory disease, therapeutic approaches have shifted from treatment of symptoms with bronchodilators to treatment of the underlying disease with antiinflammatory agents. Along with concerns about corticosteroid side effects on the part of both physicians and patients, this shift has motivated researchers to develop and test new agents with antiinflammatory capabilities. The leukotrienes are endogenous mediators with three inflammatory effects: they increase vascular permeability, recruit other inflammatory leukocytes, and induce bronchoconstriction. A number of antileukotriene agents are in various stages of development. Zileuton, a leukotriene synthesis inhibitor, has been shown to improve airway function and reduce asthma-symptoms, although there is some concern over liver toxicity. Zafirlukast, montelukast, and pranlukast, three new leukotriene receptor antagonists, have similar benefits and have not been associated with serious increases in liver enzymes. It is hoped that new antiinflammatory drugs will provide clinicians with targeted and effective asthma treatments that do not bear the potential risks of corticosteroid therapy.