Pharmacokinetics and metabolism of adriamycin in man

A pharmacokinetic evaluation o f adriamycin and its metabolites was undertaken in cancer patients treated according to an intermittent single high-dosage schedule. The long plasma half-life of adriamycin and metabolites, 26.7 hours, was similar to that of daunorubicin and its metabolites. Lang plasma half-life o f adriamycin, 16.7 hours, was shorter than that of its metabolites, 31.7 hours. In addition to differences in the metabolism of the two drugs, the cumulative 5 day urinary excretion of adriamycin and its metabolites was only 5.7% of the administered dose in contrast to 23% for daunorubicin and its metabolites. This study establishes that after a single intravenous dose plasma levels o f adriamycin are maintained for long periods; it lays a rational foundation for the empirically effective intermittent single high-dosage schedule. That adriamycin undergoes extensive metabolic degradation in patients is described for the first time.