Valrubicin is an anthracycline that affects a variety of inter-related biological functions, most of which involve nucleic acid metabolism. It readily penetrates into cells, where after DNA intercalation, it inhibits the incorporation of nucleosides into nucleic acids, causes extensive chromosomal damage, and arrests cell cycle in G2. Although valrubicin does not bind strongly to DNA, a principal mechanism of its action, mediated by valrubicin metabolites, is interference with the normal DNA breaking-resealing action of DNA topoisomerase II.
Valrubicin is a semisynthetic analog of the anthracycline doxorubicin, and is administered by infusion directly into the bladder.
Valrubicin is metabolized to two primary metabolites: N-trifluoroacetyladriamycin and N-trifluoroacetyladriamycinol.
The primary anticipated complications of overdosage associated with intravesical administration would be consistent with irritable bladder symptoms. Myelosuppression is possible if valrubicin is inadvertently administered systemically or if significant systemic exposure occurs following intravesical administration (e.g., in patients with bladder/rupture perforation). The maximum tolerated dose in humans by either intraperitoneal or intravenous administration is 600 mg/m2.