Chemotherapy is the use of anti-cancer drugs to kill cancer cells. Chemotherapy may be used in combination with other cancer therapies, such as surgery, targeted therapeutics, hormone therapies or radiation therapy, depending on the type of cancer being treated. Chemotherapeutic agents are highly toxic because they inhibit the basic cell processes required for growth, which is how they kill cancer cells. A number of chemotherapy drugs have been developed to target cancer cells by inhibiting a range of cellular processes.
Ifosfamide
Ifosfamide is a chemotherapy agent that is considered a pro-drug--the chemical gets converted into the drug within the body. Ifosfamide is an alkylating agent. It attaches a small molecule onto strands of DNA, which severely damages the DNA. Once DNA is severely damaged, the cell can no longer make the proteins needed to grow and the cell dies. Ifosfamide is toxic to normal cells as well as cancer cells, and especially targets any cells in the body that proliferate quickly, such as bone marrow cells that give rise to the blood. According to the University of Pennsylvania, ifosfamide can cause a number of blood-related side effects, including a decrease in white and red blood cells, and a decrease in platelets in the blood. Ifosfamide can also cause nausea, hair thinning and loss, and bladder and kidney defects.
Irinotecan
Irenotecan is a chemotherapy drug that prevents cells from dividing by inhibiting the duplication of DNA. In cell division, two strands of DNA are wound around each other in a spiral, and the strands must be separated so that the DNA can be replicated and passed on to two daughter cells. The proteins required for part of this unwinding are called topoisomerases, and irenotecan is a topoisomerase inhibitor. Therefore, topoisomerase stops cell division by preventing the replication of DNA. Irenotecan affects both cancer cells and normal cells throughout the body. The University of Kentucky reports that chemotherapy with irenotecan usually lowers white and red blood cell counts, causes diarrhea and nausea, and leads to hair loss.
Mercaptopurine
Mercaptopurine is a chemotherapy drug that is classified as an antimetabolite. Normal cells contain molecules called metabolites, which help support the metabolism of the cell, giving the cell the energy it needs to divide. Antimetabolites are chemicals that interact with and inhibit metabolic pathways within the cell, so the pathways become non-functional. Flooding the cell with antimetabolites, like mercaptopurine, halts cell division. Like other chemotherapy drugs, use of mercaptopurine often leads to side effects, as mercaptopurine affects normal cells as well as cancer cells. The University of Pennsylvania reports that mercaptopurine causes a decrease in the amounts of white blood cells, red blood cells and platelets. Less common side effects of the drug may include ulcers, liver changes, and skin rashes.
