[Pharmacokinetics of new anthracyclines]

Several new anthracyclines have been recently made available for clinical use or for clinical trials. Each molecule is characterized by original metabolic and pharmacokinetic features, which can be compared to those of the reference anthracyclines, doxorubicin and daunorubicin. Idarubicin is transformed into idarubicinol to a high extent, similarly to the transformation of daunorubicin to daunorubicinol, whereas the 13-dihydroderivatives of esorubicin, epirubicin or pirarubicin are present in plasma at lower levels than the parent drugs. Epirubicin is the only anthracycline able to form glucuronides, and pirarubicin can be transformed into doxorubicin itself. The elimination half-life of epirubicin or esorubicin is similar to that of doxorubicin (30 h) and the elimination half-life of unchanged idarubicin or pirarubicin is shorter (15-20 h). The novel anthracyclines have generally a higher plasma clearance than doxorubicin or daunorubicin, and a higher volume of distribution. Less than 10% of the injected dose of any anthracycline is found in urines, the major elimination pathway being the bile. The knowledge of anthracycline pharmacokinetics may allow the prediction of their behavior when special administrations are used (continuous infusion, locoregional therapy...).