Class: Anthracycline antibiotic – cytotoxic chemotherapy.
- Structure: Epimer of doxorubicin (difference at the C-4′ hydroxyl group) → slightly different pharmacokinetics and toxicity profile.
Mechanism of Action
- Intercalates into DNA → inhibits topoisomerase II, preventing DNA replication and transcription.
- Generates free radicals → oxidative damage to DNA, lipids, and proteins.
- Induces apoptosis in dividing tumor cells.
Clinical Uses
- Breast cancer (adjuvant, neoadjuvant, metastatic).
- Gastrointestinal cancers (gastric, esophageal).
- Soft tissue sarcomas.
- Sometimes in lymphomas (component of CHOP-like regimens).
Dosing
- IV infusion:
- Breast cancer: 60–120 mg/m² every 21 days (dose depending on regimen and combination therapy).
- Doses often adjusted for hepatic impairment.
- Cumulative lifetime dose: ~900 mg/m² (slightly higher than doxorubicin; less cardiotoxic).
Toxicities
- Cardiotoxicity: dose-dependent (less than doxorubicin), may cause CHF or reduced LVEF.
- Myelosuppression: neutropenia, thrombocytopenia, anemia (dose-limiting).
- Nausea, vomiting, mucositis, alopecia.
- Extravasation risk → can cause severe tissue necrosis.
- Secondary leukemia (rare, mostly AML).
Monitoring
- CBC before each cycle.
- Cardiac function (ECHO or MUGA) prior to therapy and periodically, especially with high cumulative doses.
- Liver function tests.
- Monitor infusion site for extravasation.
In summary:
Epirubicin is an anthracycline chemotherapy similar to doxorubicin, with slightly reduced cardiotoxicity. It is widely used in breast cancer and GI malignancies. Key concerns are myelosuppression, cumulative cardiotoxicity, and tissue extravasation.