Topotecan

Chemical structure of Topotecan

Topotecan is a chemotherapy medication used primarily in the treatment of ovarian cancer, small cell lung cancer, and cervical cancer. It is a topoisomerase inhibitor, specifically inhibiting topoisomerase I, an enzyme crucial for DNA replication.

Mechanism of Action

Topotecan works by inhibiting the action of topoisomerase I, an enzyme that facilitates the unwinding of DNA necessary for DNA replication and transcription. By stabilizing the DNA-topoisomerase I complex, topotecan prevents the relegation of the DNA strand, leading to DNA damage and ultimately cell death. This mechanism is particularly effective in rapidly dividing cancer cells.

Clinical Uses

Topotecan is approved for use in several types of cancer:

• Ovarian cancer: It is used in patients with metastatic ovarian cancer after disease progression following initial or subsequent chemotherapy.
• Small cell lung cancer: Topotecan is used as a second-line treatment for patients with small cell lung cancer who have relapsed after first-line chemotherapy.
• Cervical cancer: In combination with cisplatin, topotecan is used for the treatment of stage IV-B, recurrent, or persistent cervical cancer.

Administration and Dosage

Topotecan is administered either orally or intravenously. The dosage and schedule depend on the type of cancer being treated, the patient's body surface area, and their overall health status. It is typically given in cycles, with periods of treatment followed by rest periods to allow the body to recover.

Side Effects

Common side effects of topotecan include:

• Myelosuppression, leading to low blood cell counts
• Nausea and vomiting
• Diarrhea
• Fatigue
• Alopecia (hair loss)

Patients receiving topotecan are monitored closely for signs of infection due to neutropenia, a condition of abnormally low neutrophil counts.

Related Pages

• Chemotherapy
• Topoisomerase inhibitor
• Ovarian cancer
• Small cell lung cancer
• Cervical cancer