This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Asthma, Subject name: Pharmacology
Montelukast mechanism of action is? 
Select and explain. 
A. Competitive inhibitor of leukotriene synthesis, B. Inhibits alpha receptor, C. Beta receptor agonist, D. Non-competitive inhibitor of leukotriene synthesis
A: Competitive inhibitor of leukotriene synthesis
Answer: A: Competitive inhibitor of leukotriene synthesis 
Explanation: ANSWER: (A) Competitive inhibitor of leukotriene synthesisREF: Goodman and Gillman's 11TH edition p. 478"Zafirlukast and Montelukast are leukotriene receptor antagonists. Leukotriene-modifying drugs act either as competitive antagonist of leukotriene receptors or by inhibiting the synthesis of leukotriene"