antileukotriene

an·ti·leu·ko·tri·ene

(an'tē-lū'kō-trī'ēn), A drug that prevents or alleviates bronchoconstriction in asthma by blocking the production or action of naturally occurring leukotrienes; may also be useful in psoriasis.

Leukotrienes are eicosanoids derived from arachidonic acid, which is present in cell membranes. The cysteinyl leukotrienes, which are elaborated by bronchopulmonary mast cells, eosinophils, and probably alveolar macrophages, have been shown to mediate bronchoconstriction induced by exercise, hyperventilation in cold air, aspirin, and inhaled allergens. They act by stimulating a specific receptor, known as cysteinyl leukotriene receptor type 1 (CysLT1). Antileukotrienes having clinical usefulness in asthma include zileuton, which inhibits 5-lipoxygenase, an enzyme critical in the biosynthesis of leukotrienes, and leukotriene receptor antagonists (cinalukast, montelukast, zarirlukast, and others). Antileukotrienes reverse bronchconstriction in asthma to a lesser degree than β₂-adrenergic agonists, but their effects are additive to those of the latter agents. In chronic asthma, antileukotrienes improve peak flow and FEV₁ and reduce the frequency and severity of acute asthmatic attacks, the need for β₂-agonists, and the need for corticosteroid rescue. They are particularly effective in the prophylaxis of asthma induced by exercise and aspirin. In contrast, many people with allergic asthma show little or no response. Antileukotrienes are not indicated in the treatment of an acute asthmatic attack or in mild, intermittent asthma controlled adequately with occasional use of inhaled β₂-agonists. They have not been recommended as a substitute for inhaled corticosteroids in prophylaxis of asthma. Antileukotrienes are administered orally or by inhalation. Both onset and waning of clinical effects are gradual. Side-effects are minimal, but drug interactions may occur because of interference with cytochrome P-450 enzymes. Rare transitory elevations of hepatic aminotransferase have been reported with some agents.

antileukotriene

Any of a class of agents that either interferes with leukotriene synthesis or antagonises leukotriene receptors, which are as effective as cromolyn or theophylline, and may reduce the amount of inhaled steroids needed to control inflammation.
Antileukotrienes
LTD4 receptor antagonists (Zafirkulast-Accolate)

Pros
LTD4-induced bronchoconstriction, early and late responses, exercise challenge, cold-induced asthma, chronic asthma.

5-Lipoxygenase inhibitor (Zileutron-Zyflo)

Pros
Asthma induced by exercise, cold, aspirin, bronchial hyperresponsiveness.

FLAP inhibitors (5-lipoxygenase-activating protein inhibitor)
Pros
Early and late responses and cold-induced asthma.