Agent causing hemorrhagic cystitis
## **Core Concept**
Hemorrhagic cystitis is a condition characterized by bleeding from the bladder mucosa, leading to blood in the urine. It can be caused by various factors, including infections, radiation, and certain medications. The question focuses on identifying an agent that can cause this condition.
## **Why the Correct Answer is Right**
The correct answer, **Cyclophosphamide**, is a chemotherapy medication known to cause hemorrhagic cystitis as a side effect. This occurs because cyclophosphamide is metabolized to acrolein, a toxic compound that can damage the bladder mucosa, leading to bleeding. The risk of hemorrhagic cystitis is dose-dependent and can be mitigated by adequate hydration and the use of mesna (sodium 2-sulfanylethanesulfonate), which binds to acrolein in the urine and prevents bladder toxicity.
## **Why Each Wrong Option is Incorrect**
- **Option A:** While certain infections can cause hemorrhagic cystitis, the option is not specified, making it impossible to assess its correctness directly.
- **Option B:** If this option were a common cause of hemorrhagic cystitis, it would be a well-known association; however, without specifying what "B" represents, it's hard to directly refute it. Generally, radiation (not listed) is a known cause, but if "B" were radiation, it would still not be the best answer given the direct association of cyclophosphamide with this condition.
- **Option D:** Without knowing what "D" represents, it's challenging to provide a direct refutation. However, given the known side effects of cyclophosphamide, options other than cyclophosphamide are less likely to be correct if they do not have a well-documented association with hemorrhagic cystitis.
## **Clinical Pearl / High-Yield Fact**
A key point to remember is that **mesna** is used to prevent hemorrhagic cystitis in patients receiving cyclophosphamide or ifosfamide chemotherapy. This protective measure is crucial in patients undergoing chemotherapy with these agents to prevent bladder toxicity.
## **Correct Answer: C. Cyclophosphamide**