Doxorubicin is considered one of the strongest chemotherapy drugs for breast cancer ever invented. It can kill cancer cells at every point in their life cycle, and it's used to treat a wide variety of cancers, not just breast cancer. Doxorubicin is also known as “The Red Devil” because it is a clear bright red color. It can cause your urine or other body fluids to turn a reddish color for 1 to 2 days after a dose is given, which is normal and temporary.

Doxorubicin can cause harsh side effects such as heart toxicity (cardiotoxicity), severe nausea and vomiting, and total hair loss (alopecia). Because of its heart toxicity, doxorubicin has a maximum cumulative dose that can be given to each patient. The higher the total dose you receive over time, the greater your chance of heart side effects. Your doctor will monitor your heart before, during, and after doxorubicin treatment. Patients typically receive injections every 21 to 28 days on a specific cycle, but your dose schedule may be different.

Doxorubicin works by inhibiting an enzyme known as topoisomerase 2 and blocking RNA and DNA synthesis, which leads to cell death. Doxorubicin used to be marketed as the brand name product Adriamycin, but this has since been discontinued in the U.S., but the generic doxorubicin is still on the market. A liposomal form of doxorubicin (brand name: Doxil) is also available that allows doxorubicin to circulate in the blood for longer.