Doxorubicin (Adriamycin) is an unquestionably effective anticancer agent for 
many types of tumors, including advanced breast cancer. However, cardiotoxic 
effects of the drug have limited its use. Methods of reducing or preventing 
doxorubicin-induced cardiotoxicity have been suggested, including an 
investigational doxorubicin analog, mitoxantrone ( Novantrone ). Mitoxantrone 
was developed to reduce the cardiotoxicity associated with doxorubicin while 
maintaining effective antitumoral effects. Initial reports suggested that 
mitoxantrone might lack cardiotoxic potential; however, recent studies indicate 
that the drug can produce adverse cardiac effects (congestive heart failure), 
perhaps with similar frequency to that observed with doxorubicin. It is doubtful 
that mitoxantrone will be a significant advance over doxorubicin if direct 
comparative studies reveal a similar incidence of cardiomyopathy.