6 Cytotoxic Drugs That Have Become Quintessential to Treat Cancer

Medical treatment of any disease involves three basic steps: diagnosis, treatment, and rehabilitation. Diagnosis can be defined as identifying a certain ailment based on its symptoms; treatment is nothing but actively performing medical procedures and therapies so as to cure a disease. Rehabilitation can be defined as the process of providing support to a patient who is recovering from a disease so as to help him to reacquire, relearn, or regain the strength, ability and skills he possessed before contracting the disease. At each and every step, be it diagnosis, treatment, or rehabilitation, drugs play an important part to smoothen the process.

Cytotoxic drugs form an extremely important component of the medical treatment of cancer. ‘Cyto’ means cells, ‘toxic’ means poison; so essentially cytotoxic drugs kill cells, thereby preventing their multiplication and replication of malignant cancerous cells, thus putting a break on the growth of cancer. Cytotoxic drugs work effectively as they possess the ability to differentiate between normal cells and cancer cells. Thus, they help in minimizing the damage on normal cells, while at the same time effectively targeting cancer cells.

Types of Cytotoxic Drugs

Different types of cytotoxic drugs exist which combat cancerous cells in different ways. Also, distinct drugs are used for the treatment of different types cancers. Some of the types of cytotoxic drugs are given below:

1. Alkylating Agents:

This type of cytotoxic drugs helps in the treatment of cancer by damaging the DNA of malignant cancerous cells. These cells, thus, by damaging the DNA of such cells deprive them of their ability to replicate or multiply. One added advantage of alkylating agents is that they work in any stage of cell cycle. However, in rare cases, these drugs may affect the bone marrow cells which are responsible for creating new blood cells. Alkylating agents are used to treat diseases like leukemia, sarcoma, multiple myeloma, etc.

2. Antimetabolites:

Antimetabolites have a slight difference in the working as compared to alkylating agents. Instead of killing the DNA, antimetabolites alter the DNA and the RNA of the cancerous cells and offer substitute DNA and RNA for normal building of cells. As a result, the cancerous cells cannot engage in the duplication function of cancerous cells. Such antimetabolites are used to treat breast cancer or cancer of intestinal tract.

3. Anthracyclines:

Anthracyclines are a type of anti-tumor antibiotics which alter the composition of the enzymes that are responsible for duplication of DNA in cells. These anti-tumor antibiotics, instead of killing or interfering with DNA of the malignant cell, bind themselves to the DNA of such cells, thereby restricting their ability to multiply. Anthracyclines are the most frequently used cytotoxic drugs.

4. Nitrosoureas:

Nitrosoureas are a special type of alkylating agents which have the special ability to travel to the brain. Normal cytotoxic drugs lack this ability as they are not capable of crossing the blood-brain barrier which prevents majority of the drugs to enter the cranial area. However, nitrosoureas possess this ability, and hence are used extensively in the treatment of brain tumors.

5. Topoisomerase Inhibitors:

Also known as plant inhibitors, topoisomerase inhibitors disrupt the composition of a specific enzyme called topoisomerases. These enzymes are responsible for separation of DNA of cancerous cells which helps in multiplication of cells. Thus, by disrupting the composition of these enzymes, topoisomerase inhibitors prevent the replicating ability of cancerous cells. Topoisomerase inhibitors are of two types, based on the enzyme which they affect- Topoisomerase I inhibitors and Topoisomerase II inhibitors.

6. Corticosteroids:

Corticosteroids are natural, hormone-based steroids which are used in treatment of various cancers so as to fasten the process of recovery. These drugs are also used in some cases to prevent the side effects of chemotherapy.

The Bottom Line

The above-mentioned cytotoxic drugs form the major chunk of medications used to treat cancer. However, apart from these, there are many others such as miotic inhibitors and different anti-tumor antibiotics which are also used to curb the spread of cancer. These drugs play a vital role in allaying the pain associated with chemotherapy along with helping in restricting the growth of cancer cells.

About the Author(s)

Akhilesh Prabhugaonkar

Akhilesh Prabhugaonkar holds a bachelor’s degree in Electronics Engineering from the reputed Vishwakarma Institute of Technology. He has a special interest in the field of forensics, world history, international relations and foreign policy, sports, agriculture, astronomy, security and oceanography. An ardent bibliophile and melophile, Akhilesh loves to write on topics of his interest and various other societal issues. This love for writing made him enter the professional world of content writing and pursue his career in this direction.