Bleomycin is primarily associated with which toxicity?

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

Answer: (A)

Bleomycin’s main toxicity is pulmonary toxicity that can progress to pneumonitis and fibrosis. The lungs are particularly vulnerable because bleomycin hydrolase, the enzyme that inactivates bleomycin, is present in low levels in pulmonary tissue, so the drug tends to accumulate there and cause oxidative damage, inflammation, and scarring of the interstitial spaces. Clinically this shows up as cough, shortness of breath, and abnormal lung imaging, and it often limits the usable dose of bleomycin. Oxygen therapy and prior chest radiation can worsen this toxicity, underscoring its lung-specific nature.

Other organ toxicities listed are not the hallmark of bleomycin. Nephrotoxicity is more characteristic of agents like cisplatin; cardiotoxicity is commonly linked to anthracyclines such as doxorubicin; and hemorrhagic cystitis is classically seen with cyclophosphamide or ifosfamide.