There are different types of drugs for chemotherapy that help kill cancer cells within the body. Let’s take a look at the various types of chemotherapeutic drugs available for cancer treatment in the following article.
One of the commonly used treatment methods for cancer is chemotherapy. They are called antineoplastic drugs that target cancer cells and cause their destruction. However, these drugs do not differentiate between rapidly dividing cancerous cells and those cells in the bone marrow, digestive tract and hair follicles that tend to divide rapidly under normal circumstances. This gives rise to many side effects of chemotherapy. Let’s have a look at these common chemotherapy drugs in the following paragraphs.
Different Types of Drugs Used in Chemotherapy
These drugs help in treating different stages of cancer. Based on the chemotherapy type, the drugs either shrink or slow the growth of tumor cells. Chemotherapy drugs tend to affect cell division or DNA synthesis and other cellular functions of the rapidly dividing cancer cells. The chemotherapy drugs are divided on the basis of their work action, chemical structure as well as their relationship to other drugs. The following are the different chemotherapy drug types used today for treatment of cancer.
Alkylating agents are cell cycle non-specific chemotherapy drugs. These drugs cause damage to the cell DNA that prevents it from reproducing further. Due to this action, they cause long-term damage to the healthy bone marrow. Thus, in some rare cases, the use of alkylating agents can lead to acute leukemia. This condition is dose dependent, which means that lower doses will not lead to leukemia. The different types of alkylating agents include –
- Nitrogen mustards like mechlorethamine, chlorambucil, cyclophosphamide, ifosfamide and melphalan
- Nitrosoureas like streptozocin, carmustine and lomustine. (These drugs are very useful in treatment of brain cancers as they can cross the blood-brain barrier)
- Alkyl sulfonates like busulfan
- Hydrazines and Triazines like procarbazine, altretamine, dacarbazine and temozolomide
- Ethylenimines like thiotepa and altretamine (hexamethylmelamine)
- Metal salts like carboplatin, cisplatin and oxaliplatin
Plant Alkaloids and Terpenoids
Chemotherapy drugs derived from plants are called plant alkaloids or mitotic inhibitors. They are cell cycle specific drugs that target cells during different phases of division. These drugs block the microtubule function that is very important for cell division. The different types of plant alkaloids are as follows –
- Vinca alkaloids like vincristine, vinblastine and vinorelbine
- Taxanes like paclitaxel and docetaxel
- Podophyllotoxins like etoposide and tenisopide
- Camptothecan analogs like irinotecan and topotecan
Antitumor antibiotics are drugs that are derived from the soil fungus Streptomyces. These are cell cycle specific and act during multiple phases of cell cycle. The different types of antitumor antibiotics are as follows –
- Anthracyclines like daunorubicin, doxorubicin, epirubicin, idarubicin and mitoxantrone
- Chromomycins like dactinomycin and plicamycin
- Miscellaneous drugs like mitomycin and bleomycin
Drugs that interfere with the topoisomerase enzymes (that help in separation of the DNA strands for further replication) are called topoisomerase inhibitors. The types of topoisomerase inhibitors used are –
- Topoisomerase I inhibitors like irinotecan and topotecan
- Topoisomerase II inhibitors like amsacrine, etoposide, etoposide phosphate and teniposide
Miscellaneous Chemotherapy Drugs
Those drugs that act in different ways and cannot be placed in a specific category are called miscellaneous chemotherapy drugs. These unique drug types are as follows –
- Ribonucleotide reductase inhibitor like hydroxyurea
- Retinoids like bexarotene, isotretinoin and tretinoin (ATRA)
- Adrenocortical steroid inhibitor like mitotane
- Antimicrotubule agent like estramustine
- Enzymes like asparaginase and pegaspargase
Types of Cancers Treated by Chemotherapy
These different drugs used in chemotherapy are used to treat different types of cancers. The following list contains the types of cancers treated by chemotherapy –
- Alkylating agents are used to treat cancers of the lung, breast and ovary as well as Hodgkin’s disease, multiple myeloma, acute and chronic leukemia, lymphoma and sarcoma.
- Antimetabolites are used to treat tumors of the breast, ovary, and the intestinal tract, leukemias and other cancers.
- Antitumor antibiotics treat breast cancer, prostate cancer, lymphoma and leukemia.
- Topoisomerase inhibitors are used for treatment of lung cancer, ovarian cancer, gastrointestinal cancer, certain leukemias and other cancers.
- Plant alkaloids help in treating breast cancer, lung cancer, myelomas, lymphomas and leukemias.
These chemotherapy drugs are mostly administered orally to the patient. These types of oral chemotherapy drugs are available in the form of capsules, liquid or tablets. There are certain chemotherapy drugs that are given in the form of injections or through intravenous therapy.
There are many side effects of chemotherapy that occur and should be discussed with the doctor before undergoing chemotherapy. For more information on cancer treatment, speak to an oncologist.