Leukotriene inhibitors and antagonists in asthma.

OBJECTIVE

This article reviews the literature on the effects of leukotrienes in asthma. In particular, the ability of recently developed receptor antagonists and synthesis inhibitors to attenuate the asthma-causing effects of leukotrienes is examined.

DESIGN

Published literature on the role of leukotrienes in asthma was reviewed. Reports of research on agents that inhibit the synthesis of leukotrienes or block leukotriene receptors were also studied.

RESULTS

Leukotrienes are endogenous molecules formed by the breakdown of a membrane constituent, arachidonic acid, via the 5-lipoxygenase enzyme pathway. This pathway ultimately produces several species of leukotrienes with various biologic activities, including generalized inflammatory effects associated with asthma: increased vascular permeability, enhanced mucous production, and decreased mucociliary transport. Particularly important in asthma, leukotriene receptors on the airways mediate a potent bronchoconstriction. Two general types of drugs have been developed with the goal of attenuating the leukotrienes' effects in inflammation and asthma: the leukotriene receptor blockers and the leukotriene synthesis inhibitors (eg, 5-lipoxygenase inhibitors).

CONCLUSIONS

The antileukotriene drugs attenuated the responses to inhaled leukotrienes and allergen challenges. These agents produced beneficial effects in cold-, exercise-, and aspirin-induced asthma, as well as clinical asthma. Many of these medications appear to be effective in the treatment of asthma; however, further clinical research is needed to determine which patients would benefit most from their use.