One type of chemotherapy used to fight cancer is alkylating agents. They work by destroying the DNA of the cancer cell, during any phase of the cell cycle. It is effective for several types of cancer including leukemia, lymphoma and Hodgkin disease. A side effect of alkylating agents is that they damage the bone marrow. In rare cases, individuals may develop leukemia if they use alkylating agents. Some of the drugs grouped as alkylating agents include mechlorethamine, streptozocin, busulfan, temozolomide and altretamine.
Antimetabolites are another class of drugs that are effective against cancer. They interfere with the replication of DNA and RNA in cancer cells during the S phase of the cell cycle. Specifically, they replace the normal components of the genetic material to prevent the cancer cell from dividing. This type of drug is used to treat several types of cancer including leukemia, breast cancer and ovarian cancer. Capecitabine, 5-fluorouracil, 6-mercaptopurine, methotrexate and gemcitabine are some of the drugs classified as antimetabolites.
Another category of chemotherapy drugs is anti-tumor antibiotics. This class of drugs targets DNA replication enzymes in cancer cells. Anti-tumor antibiotics effectively interfere with these enzymes during any phase of the cell cycle. A side effect of these drugs, especially with anthracyclines, is that they damage the heart muscle. For this reason, the maximum lifetime dosage for these drugs is usually capped. Daunorubicin, doxorubicin, actinomycin-D and mitoxantrone are some of the anti-tumor antibiotics.
Topoisomerase inhibitors are another type of chemotherapy drug that targets DNA replication enzymes. Specifically, topoisomerase inhibitors interfere with the topoisomerase enzyme, which is involved in separating the DNA strands prior to replication. These drugs are effective against several types of cancers including leukemia, lung cancer, ovarian cancer and GI cancers. There are two types of drugs within this group. Topotecan and irinotecan are topoisomerase I inhibitors. Etoposide and teniposide are topoisomerase II inhibitors. A side effect of topoisomerase II inhibitors is an increased risk of developing acute myelogenous leukemia.
Drugs derived from plant alkaloids and natural products are grouped in the mitotic inhibitor class. They work by stopping cell division during the M phase of the cell cycle or by damaging enzymes that produce proteins required for cell division during any phase of the cell cycle. A side effect of mitotic inhibitors is peripheral nerve damage. Some of the drugs in this category include paclitaxel, docetaxel, ixabepilone, vinblastine and estramustine. They are used to treat several types of cancer including lymphoma, breast cancer and lung cancer.
Corticosteroids are hormone drugs that are used to treat multiple myeloma, lymphoma and leukemia. Prednisone, methylprednisolone and dexamethasone are corticosteroids that are used to treat nausea and vomiting associated with other chemotherapy drugs. In this capacity, these drugs are considered anti-emetics and not chemotherapy.
1. “What are the Different Types of Chemotherapy Drugs?” American Cancer Society. https://www.cancer.org/Treatment/TreatmentsandSideEffects/TreatmentTypes/Chemotherapy/ChemotherapyPrinciplesAnIn-depthDiscussionoftheTechniquesanditsRoleinTreatment/chemotherapy-principles-types-of-chemo-drugs
2. “Types of Chemotherapy.” Chemocare. https://www.chemocare.com/whatis/types_of_chemotherapy.asp