Which class of chemotherapy agents includes drugs for which cumulative dose monitoring is especially important due to cardiotoxicity risk?

• A. Antimetabolites
• B. Alkylating agents
• C. Anthracyclines
• D. Antiangiogenesis inhibitors

Answer: (C)

The idea here is that some chemotherapy drugs cause damage to the heart in a way that builds up with the total amount given over time, so doctors carefully track the cumulative dose to protect cardiac function. Anthracyclines are the classic example. Drugs like doxorubicin, daunorubicin, idarubicin, and epirubicin can cause dose-dependent cardiotoxicity, meaning the risk of heart failure increases as the lifetime exposure accumulates. Because of this, there’s a recommended lifetime dose limit (for doxorubicin, about 450–550 mg/m2, though exact numbers vary by protocol). In practice, clinicians monitor heart function with imaging and may use protective strategies or formulations to reduce risk when higher cumulative exposure is anticipated.

Other classes can have cardiac risks, but they’re not defined by a clear, cumulative-dose cardiotoxicity that drives monitoring in the same way. Antimetabolites primarily affect rapidly dividing cells with toxicities like mucositis or cytopenias rather than a predictable, dose-related heart injury. Alkylating agents can have several toxicities, including cardiac effects in some cases, but the hallmark practice of lifelong cumulative-dose monitoring for heart protection is most associated with anthracyclines. Antiangiogenesis inhibitors can affect the heart as well, but their cardiac effects aren’t the classic cumulative-dose issue that guides this monitoring.