Etoposide is a chemotherapy medication used in the treatment of lung cancer, testicular cancer, and certain lymphomas. It is frequently used in combination with other chemotherapy agents.

It belongs to a class of drugs known as topoisomerase II inhibitors.

Etoposide works by interfering with topoisomerase II, an enzyme that helps unwind DNA during replication. By inhibiting this enzyme, etoposide may cause DNA strands to break, preventing cancer cells from dividing and leading to cell death.

Because normal cells also rely on DNA replication, particularly those that divide quickly, etoposide may affect healthy tissues and lead to side effects such as reduced blood counts and increased risk of infection.