Do lower doses of doxorubicin maintain efficacy and reduce toxicity in patients with human neoplasia?
Lower doses of doxorubicin did not significantly alter remission rates, but irreversible congestive heart failure still occurred at cumulative doses of 240-390 mg/m2, highlighting the need for myocardial function monitoring.
Because patients treated with 60-90 mg/m2 every three to four weeks reach cardiotoxic doses of 550 mg/m2 within 36 weeks, prolonged treatment with Adriamycin is limited. The purpose of this study was to determine whether lower doses could be given over longer periods without loss of efficacy. Good risk patients treated with 75, 60, or 45 mg/m2 had remission rates of 25, 27, and 19%; poor risk patients treated with 50 and 25 mg/m2 had remission rates of 16 and 12% respectively. Although a dose response was identified, there were no statistically significant differences in remission rates, durations of remission, or toxicities in the dose schedules studied. Irreversible congestive heart failure occurred in five patients with cumulative doses of 240-390 mg/m2. Unless rapid remission induction is urgent, we recommend 60 mg/m2 X four doses and measurement of myocardial function if treatment is to continue.
OʼBryan et al. (1977) studied this question.