This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy, Subject name: Pharmacology
Hemorrhagic cystitis is caused by 
Select and explain. 
A. Cyclophosphamide, B. 6 mercaptounrine, C. 5 flurouracil, D. Busulfan
A: Cyclophosphamide
Answer: A: Cyclophosphamide 
Explanation: Refer Katzung 11/e p500 It is a prodrug and is activated BBy hepatic biotransformation to aldophosphamade. One of the degradation products is acrolein that is responsible for hemorrhagic cystitis