A breast cancer patient receiving adriamycin-based chemotherapy develops a declining left ventricular ejection fraction. The risk of this toxicity becomes clinically significant above which cumulative dose?

• A 150 mg/m2
• B 250 mg/m2
• C 450 to 550 mg/m2 ✓
• D 800 mg/m2

Explanation

Doxorubicin causes dose dependent, usually irreversible dilated cardiomyopathy through free radical injury to cardiac myocytes. The incidence rises steeply beyond a cumulative dose of approximately 450 to 550 mg/m2, so total lifetime dosing is capped at this level unless dexrazoxane, an iron chelator cardioprotectant, is given. Bleomycin causes pulmonary fibrosis, cisplatin nephrotoxicity, and vincristine peripheral neuropathy, making these the classic paired drug-toxicity facts.

Reference: Katzung Basic and Clinical Pharmacology, 16th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.