Epirubicin (DB00445): A Comprehensive Monograph

Executive Summary

Epirubicin is a semisynthetic anthracycline antibiotic that serves as a cornerstone agent in modern oncologic practice.[1] Classified as a small molecule, it is primarily employed as a cytotoxic chemotherapy drug, most notably in the adjuvant treatment of breast cancer in patients with axillary node involvement following surgical resection.[1] Its core mechanism of action is multifaceted, centered on its function as a topoisomerase II inhibitor and a potent DNA intercalator. By forming a stable complex with DNA and inhibiting key enzymatic processes, Epirubicin effectively disrupts DNA and RNA synthesis, leading to the programmed death of rapidly proliferating cancer cells.[1]

A defining characteristic of Epirubicin is its unique stereochemistry; it is the 4'-epi-isomer of the widely used anthracycline, doxorubicin.[1] This specific spatial orientation of a hydroxyl group on the daunosamine sugar moiety fundamentally alters its metabolic profile and pharmacokinetic disposition, resulting in faster systemic clearance and a comparatively more favorable toxicity profile.[4] This structural modification is particularly associated with reduced cardiotoxicity, a major dose-limiting factor for the anthracycline class.[4]

Despite its improved safety profile relative to doxorubicin, Epirubicin therapy is associated with significant and predictable toxicities that require diligent management. The principal dose-limiting toxicities are acute, reversible myelosuppression, manifesting as severe neutropenia and leukopenia, and a cumulative, dose-dependent cardiotoxicity that can lead to potentially fatal congestive heart failure months to years after treatment completion.[5] Furthermore, a recognized long-term risk is the development of secondary malignancies, including acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS).[8]