Pharmacology · Class
Leukotriene modifiers !
Tablets that block cysteinyl leukotrienes, mediators that narrow and inflame the airways. Add-on controllers in asthma and allergic rhinitis.
Updated 2026-11-01
What they are
Oral asthma controllers that act on the leukotriene pathway: receptor antagonists of CysLT1 (montelukast, zafirlukast) and the 5-lipoxygenase inhibitor zileuton. They are less effective than inhaled corticosteroids and are used as add-on therapy, in exercise-induced bronchoconstriction, in aspirin-exacerbated respiratory disease and in allergic rhinitis.
Mechanism of action
Mast cells and eosinophils make leukotrienes from arachidonic acid through 5-lipoxygenase. The cysteinyl leukotrienes (LTC4, LTD4, LTE4) act on the CysLT1 receptor to contract airway muscle, increase mucus and vascular leak, and attract eosinophils. Receptor antagonists block CysLT1; zileuton stops leukotriene synthesis.
Target: Cysteinyl leukotriene receptor 1 (CYSLTR1); 5-lipoxygenase (ALOX5) for zileuton
Drugs in this class
Others in the class
- Zafirlukast
- Zileuton
- Pranlukast
Test yourself
Think of the answer, then tap the question to see it.
Which receptor do montelukast and zafirlukast block?
The cysteinyl leukotriene receptor CysLT1, the receptor of LTD4.
Which enzyme does zileuton inhibit?
5-lipoxygenase, so leukotriene synthesis from arachidonic acid stops.
What boxed warning does montelukast carry?
Serious neuropsychiatric events, such as agitation, sleep disturbance, depression and suicidal thoughts or behaviour.
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - MONTELUKAST SODIUM tablet, chewable MONTELUKAST SODIUM tablet, film coated (DailyMed (U.S. National Library of Medicine), 2026); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 44 (McGraw Hill, 2023).
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Representative model, for educational purposes only.