Chemotherapy is a multipurpose term most commonly used for the treatment modality used for the management of tumors and cancerous diseases. This term is also used for the treatment of infectious diseases due to microbial organisms. Chemotherapy for cancer management is usually carried out by one or more than one antineoplastic agents. Sometimes, it is combined with either radiotherapy or surgery to enhance it effects. All the chemotherapeutic agents share a common property of cytotoxicity. These agents kill the rapidly dividing cells, the main problem in cancerous diseases. However, few newer antineoplastic drugs have been discovered who lack the property of cytotoxicity and they are called monoclonal antibodies. A large number of chemotherapeutic agents are available all over the world.
They are classified as:
1. Alkylating agents
3. Vinca alkaloids
4. Topoisomerase inhibitors
5. Cytotoxic antibiotic agents
What is Chemotherapy used for?
As already discussed, Chemotherapy serves the following three main purposes in the management of malignant diseases:
- Curing the cancer – rare
- Palliative treatment – alleviating the symptoms due to malignant disease
- Prolonging the life of an individual
Chemotherapy is one of the options in almost all the types of tumors if diagnosed at an early stage.
It is commonly used for the management of following tumors:
- Ovarian tumors
Chemotherapeutic agents have also been used for many other inflammatory, autoimmune and infectious diseases like:
- Crohn’s disease
- Ulcerative colitis
- Ankylosing spondylitis
- Psoriatic arthritis
- Rheumatoid arthritis
- CREST syndrome
- Multiple sclerosis
Common side effects of Chemotherapy
Most of the side effects of chemotherapeutic agents are just the extension of therapeutic effects. The basic principle of killing the rapidly multiplying cells is dangerous for the normal cells possessing the property of rapid multiplication. During the use of these agents rapidly multiplying normal cells like of gastrointestinal tract, bone marrow and hair follicles are also affected badly. So the most common side effects of chemotherapeutic agents are:
- Immunosuppression – Chemotherapy suppresses the immune system of the body and patients are prone to have different types of infections that may or may not be life threatening. During Chemotherapy this must be closely monitored. Patients usually develop viral infections like Herpes Simplex, shingles (varicella zoster virus) and sepsis. This occurs due to the suppression of bone marrow cells make white blood cells. The most common infection associated with Chemotherapy is Typhlitis. It is a life threatening infection of the gastrointestinal tract which manifests as fever with chills, nausea, vomiting, diarrhea, distention and pain in abdomen.
- Unusual tiredness and fatigue – it occurs due to anemia associated with Chemotherapy. Anemia also occurs due to bone marrow suppression and it may be improved by injecting synthetic erythropoietin, iron supplements and by blood transfusion.
- Gastrointestinal symptoms – cells lining the GIT are also the main targets of Chemotherapy. So, patients may complain of nausea, vomiting, diarrhea or constipation. Loss of appetite also occurs resulting in malnutrition and dehydration. This side effect is usually controlled with the help of strong antiemetics like ordansetron and granisetron.
- Hair damage and loss – hair follicles are one of the rapidly multiplying cells and Chemotherapy destroys them resulting in loss of hair. In some cases the hair are not completely lost but gets curled.
- Neuropathy – Chemotherapy induced neuropathy is very common among the patients. It causes pain, paralysis and cognitive impairment. All these effects are reversible once the course is discontinued.
- Skin – patients may have dry and red skin, and nails of fingers and toes are damaged.
- Increased thirst and unusual dryness of mouth (xerostomia)
- Tumor lysis syndrome – it can be very dangerous and life threatening. It occurs during the treatment of large tumors like lymphomas. The cancerous cells are shed in large quantity during the treatment and these cells spread throughout the body causing disaster. Prophylactic treatment is usually advised during the treatment of large tumors.
- Chemotherapeutic agents can target any organ or system of the body like:
- Heart (Cardiotoxicity)
- Liver (Hepatotoxicity)
- Ear (Ototoxicity)
- Kidney (Nephrotoxicity)
- Brain (Neurotoxicity)
Chemotherapy side effects on children
The most common side effect of Chemotherapy in children is the development of secondary neoplasm after complete recovery from the primary neoplasm due to Chemotherapy. The most common secondary neoplasm is acute myeloid leukemia which may occur secondary to topoisomerase inhibitors or alkylating agents.
Chemotherapy side effects on men
The most common side effect of Chemotherapy in men is infertility. Most of the chemotherapeutic agents are gonadotoxic. So, in order to prevent the fertility prior to the initiation of Chemotherapy, semen is preserved with specialized techniques for future use. Drugs having high risk of infertility are alkylating agents like cyclophosphamide and procarbazine.
Few males complain of impotence during the use of chemotherapeutic agents.
Chemotherapy side effects on women
In women, infertility due to Chemotherapy may be secondary to premature ovarian failure in which there is loss of primordial follicles. In females cryopreservation of ovarian tissue, oocytes and embryos is carried out to preserve fertility.
Chemotherapy side effects on pregnant women
Chemotherapy is contraindicated in all the trimesters of pregnancy. It is highly teratogenic during the first trimester. All types of congenital anomalies involving any system of the human body can occur due to the use of this drug. Although it is not much teratogenic during the second and third trimester, however, it may complicate pregnancy or lead to myelosuppression of the fetus.
Chemotherapy side effects on elderly
The most common side effect associated with Chemotherapy in the elderly is the emotional disturbance and labiality. Elderly often have mood swings during the use of this drug. Moreover, it aggravates the ongoing cognitive impairment in the elderly.