Which medication in the asthma regimen is a leukotriene receptor antagonist?

• A. Theophylline
• B. Montelukast
• C. Fluticasone
• D. Salmeterol

Answer: (B)

Leukotriene receptor antagonists block the action of leukotrienes, inflammatory mediators that promote bronchoconstriction and airway inflammation in asthma. Montelukast selectively blocks the CysLT1 receptor for leukotrienes C4, D4, and E4, preventing their effects and helping to reduce bronchoconstriction and inflammation. Theophylline is a bronchodilator from a different class (methylxanthine) that works mainly by phosphodiesterase inhibition and adenosine antagonism. Fluticasone is an inhaled corticosteroid that reduces airway inflammation through gene regulation and glucocorticoid receptor action. Salmeterol is a long-acting beta-2 agonist that causes bronchodilation by stimulating beta-2 receptors. Therefore, montelukast is the leukotriene receptor antagonist.