Dexrazoxane: how it works in cardiac and tumor cells. Is it a prodrug or is it a drug?

Dexrazoxane is highly effective in reducing anthracycline-induced cardiotoxicity and extravasation injury and is used clinically for these indications. Dexrazoxane has two biological activities: it is a prodrug that is hydrolyzed to an iron chelating EDTA-type structure and it is also a strong inhibitor of topoisomerase II. Doxorubicin is able to be reductively activated to produce damaging reactive oxygen species. Iron-dependent cellular damage is thought to be responsible for its cardiotoxicity. The available experimental evidence supports the conclusion that dexrazoxane reduces doxorubicin cardiotoxicity by binding free iron and preventing site-specific oxidative stress on cardiac tissue. However, it cannot be ruled out that dexrazoxane may also be protective through its ability to inhibit topoisomerase II.