Which medication has the potential for cardiotoxicity, especially if the patient's baseline ejection fraction is low?

Trastuzumab is a monoclonal antibody commonly used in the treatment of HER2-positive breast cancer. One of the critical concerns associated with trastuzumab therapy is its potential for cardiotoxicity, particularly in patients who already have a compromised cardiac function, such as those with a low baseline ejection fraction.

The mechanism of cardiotoxicity with trastuzumab is thought to involve its effect on cardiac myocytes, leading to disruptions in the normal signaling pathways that regulate heart function. Consequently, patients receiving this agent are monitored closely for signs of heart failure and reduction in ejection fraction during treatment. This risk is particularly emphasized in patients who have pre-existing heart conditions or who have received other cancer therapies known to impact cardiac health, such as anthracyclines.

In contrast, the other medication options listed—taxanes, tamoxifen, and anastrozole—are not primarily associated with cardiotoxic effects. Taxanes can have different side effects, but their direct impact on cardiac function is not a primary concern. Tamoxifen and anastrozole are both hormonal therapies that exert their effects mainly through different mechanisms related to estrogen, and while they may have other risks, they do not carry the same specific risk of cardiotoxicity