Once upon a time, Cancer was looked upon as a dreaded term which got people worked up in more than one way – but that has changed over the years. The advent of chemotherapy treatments along with the application of cytotoxic anticancer drugs has developed remarkably in the past few years. Thanks to these treatments, cancerous cells are damaged to a point where they are rendered incapable of growing and reproducing further. Additionally, the chemotherapeutic process is said to be the most effective on cells that tend to grow actively and divide – also known as the frightening “spread” which causes so much apprehension in cancer patients.
How do anti-Cancer drugs work?
Today, there are over 100 chemo drugs used for treating cancer. These medicines may be either used in combination with other medications or simply as it is. Further, each medicine differs from the other regarding its chemical composition, the method of administration and in terms of the side effects as well. Chemotherapeutic drugs are famed for targeting cells in multiple phases while their multiplying which is known as the cell cycle. Clinical oncologists who treat cancer work with numerous drug combinations and apply various treatment protocols which are based on specified dosages & depending on the particular time of the cell phase.
These drugs, however, are unable to differentiate between malignant and benign cells which invariably results in some form of damage to the latter as well. This leads to a host of side effects such as acute nausea, weight & hair loss, fever, loose motions, muscular cramps and profuse sweating. However, auxiliary treatment has now been introduced to control and take on these side effects.
Classification of chemotherapeutic drugs
Chemotherapeutic drugs are classified according to their method of working, chemical structure and how they relate to other drugs. Thereon, certain drugs have multiple functions and belong to more than one classification. In that regard, it becomes imperative to find out the manner in which a particular drug works so that its side effects can be dealt with beforehand. This knowledge, in turn, allows oncologists to figure out which drug combinations work better along with information on which order and the amount each drug needs to be administered.
Workings of Alkylating Agents:
Alkylating agents prevent cell multiplication by causing irreversible damage to their DNA. These medicines work effectively throughout the cell cycle and are typically prescribed to treat lung, ovarian and breast cancer, lymphoma, leukaemia, multiple myeloma, Hodgkin’s disease and sarcoma. However, since theDNAse drugs can cause potential DNA damage, there’s a chance of the patient’s bone marrow getting afflicted leading to red blood cell production getting affected as well. Unfortunately, this could lead to the development of leukaemia in rare cases, which again is “dose-dependent.” This implies that the risk is lower when smaller doses of alkylating agents are given and rises proportionately with an increase in dosage. Statistics have revealed that the chances of contracting leukaemia after a patient is exposed to alkylating agents are highest about five to ten years after receiving treatment.
Some notable alkylating agents are Altretamine, Busulfan, Carmustine, Chlorambucil, Cisplatin, etc.
Antimetabolites: These are another classification of anti-cancer drugs that arrest RNA and DNA growth by substituting the normal DNA and RNA building blocks. Antimetabolites damage cells during the phase when cellular chromosomes are replicated. These are commonly used for treating blood, breast, ovarian and intestinal tract cancers. The most frequently used antimetabolites are 5-fluorouracil, Capecitabine, 6-mercaptopurine, Floxuridine, Cytarabine, Gemcitabine, etc.
Other categories: The other types of chemotherapeutic drugs are anti-tumor antibiotics, Anthracyclines, Topoisomerase Inhibitors, Mitotic Inhibitors, Corticosteroids and Differentiating Agents. Each group of drugs has a separate method of working that varies from altering the malignant cell’s internal DNA to prevent it from multiplying; interfering with enzymes that copy DNA during the cell cycle to separating DNA strands for copying to preventing cell division and prevention of chemo-induced nausea & vomiting as also acute allergic reactions.