Topotekaani

Topotekaani, known in English as topotecan, is a semi-synthetic derivative of camptothecin used in cancer chemotherapy. It inhibits DNA topoisomerase I, an enzyme required for relaxing DNA during replication. By stabilizing the topoisomerase I-DNA cleavage complex, topotecan prevents religation of single-strand breaks, leading to DNA damage and selective killing of rapidly dividing cancer cells.

Clinical use includes relapsed or platinum-sensitive ovarian cancer (often in combination with cisplatin), relapsed small cell lung cancer after first-line therapy, and platinum-treated recurrent or metastatic cervical cancer. Dosing and regimens vary by cancer type and region and may employ single-agent or combination therapy.

Topotecan is formulated for intravenous administration and as an oral capsule. Treatment typically follows multi-day schedules within 21-day cycles, with dose adjustments for renal or hepatic impairment and other patient factors.

Common adverse effects are myelosuppression (neutropenia and thrombocytopenia), fatigue, nausea, vomiting, diarrhea, and mucositis. Other risks include alopecia and increased infection susceptibility. Careful monitoring is required in patients with kidney or liver dysfunction.

It is marketed under various brand names, including Hycamtin in some markets. As a camptothecin analogue, topotecan is one of several topoisomerase I inhibitors used in oncology.