Which of the following is a common side effect of anthracycline antibiotics?

Cardiotoxicity is a well-documented side effect of anthracycline antibiotics, such as doxorubicin and daunorubicin. These agents are commonly used in chemotherapy regimens for various cancers because of their effectiveness in interfering with DNA synthesis and function. However, their use can lead to damage to the heart muscle, which can result in conditions such as cardiomyopathy and heart failure.

The mechanism behind this toxicity is thought to involve the generation of free radicals, which can lead to oxidative stress and injury to cardiac myocytes (heart muscle cells). Monitoring for signs of cardiotoxicity, such as changes in cardiac function or symptoms of heart failure, is critical in patients receiving anthracyclines. This is why cardiotoxicity is recognized as a primary concern associated with this class of drugs, making it the most appropriate answer in this context.