Lower incidence of doxorubicin-induced cardiomyopathy by once-a-week low-dose administration

A review of the literature investigating an alternative method of administering doxorubicin on a weekly basis demonstrates a lower incidence of doxorubicin-induced cardiomyopathy, as judged by endomyocardial biopsy techniques and by an apparent lower incidence of CHF as compared to older reports in the literature utilizing conventional tri-weekly administration. However, none of these studies has utilized objective methods for verifying cardiac function. The precise reason why weekly administration may induce lesser degrees of damage to the myocardium is not clearly understood. However, it appears that the lower serum concentrations obtained with this dosing regimen result in lower myocardial tissue concentrations of the drug. Though the initial data are encouraging, larger clinical trials are necessary to establish a lower incidence of cardiotoxicity with weekly low-dose doxorubicin administration. Such studies, if specifically designed to evaluate changes in myocardial function, will resolve the questions and hopefully establish the advantages of this encouraging new therapeutic modality.