A 12-year-old girl receiving combination chemotherapy for Ewing sarcoma develops painless gross haematuria. Cystoscopy shows haemorrhagic cystitis. Which drug in her regimen is responsible?

• A Vincristine
• B Doxorubicin
• C Etoposide
• D Ifosfamide ✓

Explanation

Haemorrhagic cystitis is caused by acrolein, a metabolite of oxazaphosphorines. It is classically associated with ifosfamide, whose metabolite is excreted in higher concentration in urine than that of cyclophosphamide. Mesna binds acrolein in the urinary tract and is given routinely with ifosfamide for uroprotection. Vincristine causes neuropathy, doxorubicin cardiomyopathy and etoposide myelosuppression, none of which produce haematuria.

Reference: Katzung's Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.