This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Pharmacology
A child suffering from asthma is to be treated with a drug that blocks the synthesis of leukotrienes. What drug would be an appropriate choice 
Select and explain. 
A. Cromolyn sodium, B. Montelukast, C. Zileuton, D. Theophylline
C: Zileuton
Answer: C: Zileuton 
Explanation: zileuton mech of action:- It is a 5-LOX(lipoxygenase) inhibitor, blocks LTC4/D4 as well as LTB4 synthesis. It therefore has the potential to prevent all LT induced responses including those exeed by activation of cysLT1 receptor. Duration of action of zileuton is sho. side effects:- Hepatotoxicity