Doxorubicin medak is an anthracycline antibiotic. It exerts its antitumor effect through a cytotoxic mechanism of action, in particular by intercalation into DNA, inhibition of the enzyme topoisomerase II and the formation of reactive oxygen species (ROS). All this has a detrimental effect on DNA synthesis: intercalation of the doxorubicin molecule leads to inhibition of DNA and RNA polymerase synthesis due to disturbances in basic recognition and sequence specificity. Inhibition of topoisomerase II leads to breakage of single and double DNA helices. DNA cleavage also occurs as a result of a chemical reaction with highly reactive oxygen species, such as, for example, the hydroxyl OH radical. The consequences of this are mutagenic and chromosomal aberrations.