Doxorubicin cardiotoxicity: possible roleofdigoxin inits prevention

Summary Twenty-nine patients withgynaecological cancerswho receivedover400mg ofdoxorubicin weremonitored electrocardiographically todeterminewhethercardiac glycosides counteredtheadverseeffects ofhightotal dosesof doxorubicin. Minor electrocardiographical changeswerenotedinfiveoutofsixpatients whowere notreceiving a cardiacglycoside and fouroutofsix whowerereceiving ouabain, andnoneofthe16whowere receiving digoxin. Oneotherpatient ondigoxin stopped takingitand developedcardiomyopathy. One patient onouabainalsodeveloped cardiomyopathy. Sofarnine patients ondigoxin havereceived between550and1000 mg,m2ofdoxorubicin withoutilleffect. Cardiacglycosides arethought topreventdoxorubicin cardiomyopathy bycompetitively inhibiting doxorubicin atitsreceptor sites, butouabainhasa much shorter halflifethandoxorubicin anditsmetabolites andsois lesseffective thandigoxin.