A patient who has recently completed chemotherapy reports dysuria and haematuria. Which cytotoxic drug is most likely responsible?

A patient who has recently completed chemotherapy reports dysuria and haematuria. Which cytotoxic drug is most likely responsible?

• A. Methotrexate
• B. Cyclophosphamide
• C. Doxorubicin
• D. Paclitaxel

Answer: (B)

Hemorrhagic cystitis is a known bladder-irritating toxicity caused by certain alkylating chemotherapy drugs. The key metabolite involved is acrolein, which accumulates in the urine and damages the bladder lining, producing painful, burning urination and blood in the urine. Cyclophosphamide is metabolized to acrolein, making it the classic drug in this scenario. The pattern of dysuria with hematuria after chemotherapy fits this bladder toxicity. Prophylaxis with Mesna (which binds acrolein) and good hydration are common preventive and management strategies. Other drugs listed are not typically associated with hemorrhagic cystitis as a primary toxicity, so they don’t explain the symptom cluster as clearly.

Hemorrhagic cystitis is a known bladder-irritating toxicity caused by certain alkylating chemotherapy drugs. The key metabolite involved is acrolein, which accumulates in the urine and damages the bladder lining, producing painful, burning urination and blood in the urine.

Cyclophosphamide is metabolized to acrolein, making it the classic drug in this scenario. The pattern of dysuria with hematuria after chemotherapy fits this bladder toxicity. Prophylaxis with Mesna (which binds acrolein) and good hydration are common preventive and management strategies.

Other drugs listed are not typically associated with hemorrhagic cystitis as a primary toxicity, so they don’t explain the symptom cluster as clearly.