Cyclophosphamide is associated with which notable side effect?

• A. Hemorrhagic cystitis
• B. Nausea only
• C. Hair loss only
• D. Peripheral neuropathy

Answer: (A)

Hemorrhagic cystitis is the notable toxicity linked to cyclophosphamide because its metabolite acrolein is produced during metabolism and is excreted in the urine, where it irritates and can inflame the bladder mucosa, sometimes leading to bleeding. The risk rises with higher doses and inadequate hydration. Prevention hinges on giving mesna, which binds acrolein in the urinary tract, and ensuring good hydration to dilute and flush the bladder. While nausea and hair loss can occur with chemotherapy, they are not as specific or characteristic for cyclophosphamide as bladder irritation from acrolein; peripheral neuropathy is not a typical feature of this drug. Thus hemorrhagic cystitis stands out as the key associated side effect.