Leukotriene inhibitors are a class of medications used to manage inflammatory conditions, particularly those involving the respiratory system. Leukotrienes are inflammatory molecules produced by the immune system, by various cells, including mast cells, eosinophils, and macrophages, in response to allergens, infections, or other stimuli. Leukotriene inhibitors block the action of leukotrienes.

Key points:

• Action: They help reduce inflammation, relax smooth muscles in the airways, and decrease mucus secretion.

• Asthma: They are often used as maintenance therapy to manage asthma, particularly in individuals with mild to moderate persistent asthma or exercise-induced bronchoconstriction.

• Allergic Rhinitis: They are used to treat allergic rhinitis, especially when symptoms are not adequately controlled with antihistamines or intranasal corticosteroids.

• Other Conditions: They may have other potential uses in conditions such as chronic urticaria (hives), atopic dermatitis (eczema), and exercise-induced bronchoconstriction.

• Side Effects: Common side effects may include headache, gastrointestinal disturbances (such as nausea, diarrhea, or abdominal pain), fatigue, and upper respiratory tract infections. Rare but serious side effects include neuropsychiatric events or liver toxicity.

• Two main types: Leukotriene receptor antagonists (LTRAs) block the action of leukotriene receptors on target cells. Examples: montelukast, zafirlukast, pranlukast. Leukotriene synthesis inhibitors (LTSIs) inhibit the enzyme 5-lipoxygenase, which synthesizes leukotrienes. Example: zileuton.