Doxorubicin is primarily associated with which toxicity?

• A. Nephrotoxicity
• B. Pulmonary fibrosis
• C. Cardiotoxicity
• D. Hemorrhagic cystitis

Answer: (C)

Doxorubicin’s dose-limiting toxicity is damage to the heart. It is an anthracycline that generates reactive oxygen species in cardiomyocytes, leading to oxidative stress and mitochondrial injury. Over time this accumulates, causing a dilated cardiomyopathy and potential heart failure, with risk increasing as the lifetime cumulative dose rises. Clinically, this is why heart function is monitored during treatment and why strategies like limiting exposure or using dexrazoxane may be considered. Other toxicities listed belong to different drugs (nephrotoxicity with some platinum agents, pulmonary fibrosis with bleomycin, hemorrhagic cystitis with cyclophosphamide/ifosfamide), but the hallmark toxicity of doxorubicin is cardiotoxicity.