Pharmacokinetics of 4'-epi-doxorubicin in man

The pharmacokinetics of 4'-epi-doxorubicin (4'-epi-adriamycin, 4'-epi-DX) in man can be described by a three-compartment model with a rapid distribution phase and a very long elimination phase. Urine excretion amounts to a total of about 11% of the administered dose during 48 h after drug administration, and less than 1% during the following 48 h. In plasma 4'-epi-doxorubicin is rapidly converted to five metabolites (4'-epi-doxorubicinol, aglycones and glucuronides), the concentration of the aglycones sometimes exceeding that of 4'-epi-DX. In urine only three metabolites were found in addition to the parent drug; they were identified as 4'-epi-doxorubicinol (EOH), 4'-epi-doxorubicin-glucuronide (E-Glu) and 4'-epi-doxorubicinol-glucuronide (EOH-Glu). Comparison of the pharmacokinetics and metabolic profiles of 4'-epi-DX and doxorubicin (DX) in man revealed that 4'-epi-DX eliminates faster than DX.