Doxorubicin hydrochloride is a cytotoxic anthracycline antibiotic. The recommended single-agent dose of doxorubicin HCl (Adriamycin®) for injection is 60 to 75 mg/m2 intravenously (IV) in three-week cycles. Acute myelosuppression and long term, cumulative, cardiotoxicity (congestive heart failure) are dose-limiting. Doxorubicin is active against breast cancer as a single agent and is used with other drugs in multi-agent chemotherapy regimens. In LRR breast cancer, single agent doxorubicin achieves response rates comparable to combination chemotherapy.