Anthracyclines are a class of antibiotic drugs. They are obtained from Streptomyces bacteria. They are used as a form of chemotherapy, to treat a number of cancers, inclusing blood cancer. The most important clinically are doxorubicin and daunorubicin. They act to inhibit cellular processes around DNA metabolism which results in the death of rapidly dividing cells. Most anthracyclines are administered directly into the blood. Common side effects include decreased immune cell production, nausea, vomiting and hair loss. The greatest potential side effect is dose related damage to heart tissue and modern treatment regimens are designed to minimise this risk. Research continues around new anthracycline variants and formulation with several clinical trials currently underway around the world.