![Picture](/uploads/4/7/9/5/47950691/4854522.jpg?470)
Disclaimer: This site is a part of curriculum project. The information should be used for educational purpose only.
TYPES AND CLASSIFICATION OF THE ANTICANCER DRUGS
1. ACCORDING TO CHEMICAL STRUCTURE AND SOURCES OF DRUGS:
Alkylating Agents, Antimetabolites, Antibiotics, Plant
Extracts, Hormones and others.
2. ACCORDING TO BIOCHEMISTRY MECHANISM OF ANTICANCER ACTION:
a. Block nucleic acid biosynthesis.
b. Direct influence the structure and function of DNA.
c. Interfere transcription and block RNA synthesis.
d. Interfere protein synthesis and function.
e. Influence hormone homeostasis.
3. ACCORDING TO THE CYCLE AND PHASE SPECIFICITY
OF THE DRUGS:
Cell Cycle Non Specific Agent (CCNSA), Cell Cycle Specific
Agent (CCSA)
MAJOR CLASSES OF DRUGS:
1. CYTOTOXIC DRUGS.
2. TARGETED DRUGS.
3. HORMONAL DRUGS.
FURTHER CLASSIFICATION,
Alkylating agents
Alkylating agents directly damage DNA to prevent the cancer cell from reproducing. As a class of drugs, these agents are not phase-specific; in other words, they work in all phases of the cell cycle. Alkylating agents are used to treat many different cancers, including leukemia, lymphoma, Hodgkin disease, multiple myeloma, and sarcoma, as well as cancers of the lung, breast, and ovary.
Because these drugs damage DNA, they can cause long-term damage to the bone marrow. In rare cases, this can eventually lead to acute leukemia. The risk of leukemia from alkylating agents is “dose-dependent,” meaning that the risk is small with lower doses, but goes up as the total amount of the drug used gets higher. The risk of leukemia after getting alkylating agents is highest about 5 to 10 years after treatment.
[14,23]
There are different classes of alkylating agents, including:
- Nitrogen mustards: such as mechlorethamine (nitrogen mustard), chlorambucil, cyclophosphamide (Cytoxan®), ifosfamide, and melphalan
- Nitrosoureas: which include streptozocin, carmustine (BCNU), and lomustine
- Alkyl sulfonates: busulfan
- Triazines: dacarbazine (DTIC) and temozolomide (Temodar®)
- Ethylenimines: thiotepa and altretamine (hexamethylmelamine)
Antimetabolites
Antimetabolites are a class of drugs that interfere with DNA and RNA growth by substituting for the normal building blocks of RNA and DNA. These agents damage cells during the S phase. They are commonly used to treat leukemias, cancers of the breast, ovary, and the intestinal tract, as well as other types of cancer. [14,21,23]
Examples of antimetabolites include:
- 5-fluorouracil (5-FU)
- 6-mercaptopurine (6-MP)
- Capecitabine (Xeloda®)
- Cladribine
- Clofarabine
Anti-tumor antibiotics
Anthracyclines Anthracyclines are anti-tumor antibiotics that interfere with enzymes involved in DNA replication. These drugs work in all phases of the cell cycle. They are widely used for a variety of cancers. A major consideration when giving these drugs is that they can permanently damage the heart if given in high doses. For this reason, lifetime dose limits are often placed on these drugs[14,21,23]
Topoisomerase inhibitors
These drugs interfere with enzymes called topoisomerases, which help separate the strands of DNA so they can be copied. They are used to treat certain leukemias, as well as lung, ovarian, gastrointestinal, and other cancers.[23]
Mitotic inhibitors
Mitotic inhibitors are often plant alkaloids and other compounds derived from natural products. They can stop mitosis or inhibit enzymes from making proteins needed for cell reproduction.
These drugs work during the M phase of the cell cycle but can damage cells in all phases. They are used to treat many different types of cancer including breast, lung, myelomas, lymphomas, and leukemias. These drugs are known for their potential to cause peripheral nerve damage, which can be a dose-limiting side effect.[14]
Corticosteroids
Steroids are natural hormones and hormone-like drugs that are useful in treating some types of cancer (lymphoma, leukemias, and multiple myeloma), as well as other illnesses. When these drugs are used to kill cancer cells or slow their growth, they are considered chemotherapy drugs.
Corticosteroids are also commonly used as anti-emetics to help prevent nausea and vomiting caused by chemotherapy. They are used before chemotherapy to help prevent severe allergic reactions (hypersensitivity reactions), too. When a corticosteroid is used to prevent vomiting or allergic reactions, it’s not considered chemotherapy. [14,23]
REFERENCE:-
http://www.cancer.org/treatment/treatmentsandsideeffects/treatmenttypes/chemotherapy/chemotherapyprinciplesanin-depthdiscussionofthetechniquesanditsroleintreatment/chemotherapy-principles-types-of-chemo-drugs