Topotecan — Drug Monograph

Brand names: Hycamtin

Drug class: Topoisomerase Inhibitor

Mechanism of Action

Camptothecin analog. Reversibly binds and stabilizes the topoisomerase I-DNA cleavage complex, causing DNA strand breaks during replication. S-phase specific. Unlike irinotecan, topotecan is the active form (not a prodrug).

FDA Indications

• Metastatic ovarian carcinoma after failure of initial or subsequent chemotherapy
• Small cell lung cancer (SCLC) sensitive disease relapse
• Stage IVB, recurrent, or persistent cervical carcinoma with prior chemotherapy (in combination with cisplatin)

Common Side Effects

• Myelosuppression (neutropenia, thrombocytopenia, anemia)
• Nausea and vomiting
• Diarrhea
• Alopecia
• Fatigue
• Mucositis

Clinical Pearl

Topotecan is particularly myelosuppressive — G-CSF support is often used prophylactically or therapeutically. The 5-day schedule produces more consistent drug exposure than other schedules. Thrombocytopenia is often more dose-limiting than neutropenia in heavily pretreated ovarian cancer patients.

Related Therapies & Mechanisms

• Etoposide (VePesid) — Topoisomerase Inhibitor · SCLC
• Carboplatin (Paraplatin) — SCLC
• Cisplatin (Platinol) — SCLC
• Irinotecan (Camptosar) — Topoisomerase Inhibitor