People with certain types of cancer may receive a chemotherapy drug called Toposar. It works to prevent cancer cells from growing and dividing by causing DNA strands to break. This drug comes as a solution that is given slowly into a vein (an intravenous, or IV, infusion). Most people who receive this medication will experience some type of side effect, such as nausea or hair loss.
What Is Toposar?Toposar® (etoposide injection) is a prescription chemotherapy medication approved to treat cancer of the testicles in men who have not adequately responded to other treatment (chemotherapy, surgery, or radiation treatment). It is also approved to treat a type of lung cancer known as small cell lung cancer. Toposar is approved for use in combination with other chemotherapy medications.
How Does Toposar Work?Toposar belongs to a group of medicines known as podophyllotoxin derivatives. Podophyllotoxins are derived from the Mayapple tree (Podophyllum peltatum). These medications work by interfering with the action of an enzyme known as topoisomerase II.
Topoisomerase II helps relax DNA that has been tangled or overwound, which can happen when DNA is unwinding so it can duplicate (DNA duplication is necessary for cells to divide). The enzyme relaxes tightly bound DNA by cutting the DNA strands to relieve the tension and then putting the strands back together.
Toposar binds to topoisomerase II and prevents the enzyme from relaxing DNA. As a result, the DNA strands break. This prevents cells from dividing, which stops the growth of cancer cells.