Topotec contains topotecan, an anti-cancer medicine used in the treatment of certain types of cancers, especially when other treatments are no longer effective. It belongs to a class of drugs called topoisomerase I inhibitors, which interfere with cancer cell division and help stop tumour growth.

Topotecan is usually administered by injection into a vein, though it may also be available in oral form depending on the treatment plan. It is typically used under medical supervision in hospital or clinical settings.

Mechanism of Action

Topotecan works by targeting an enzyme in cells called topoisomerase I, which helps manage DNA structure during cell replication. In healthy cells, this enzyme allows the DNA to unwind and copy itself properly. However, cancer cells replicate rapidly, relying heavily on this enzyme.

By inhibiting topoisomerase I, topotecan causes breaks in the DNA strands during the replication process. These breaks cannot be repaired in time, leading to cell death. Since cancer cells divide more quickly than normal cells, they are more affected by this action.

Uses

Topotec is primarily used for cancers that have not responded to initial treatments or have returned after treatment. It is most commonly indicated for:

• Ovarian cancer that has relapsed after chemotherapy

• Small cell lung cancer that has not responded or has returned after previous treatment

• Cervical cancer, often in combination with another drug like cisplatin, for advanced stages

  Adverse Effects

  Like most chemotherapy agents, topotecan can affect both cancerous and healthy cells, especially those that grow quickly such as blood cells and cells in the digestive tract.

  Common Side Effects

  • Fatigue or weakness

  • Nausea, vomiting, or diarrhoea

  • Low white blood cell count, increasing the risk of infection

  • Low red blood cell count, which can cause anaemia

  • Low platelet count, leading to increased risk of bleeding

  • Hair thinning or hair loss