Part III Management of the Side Effects of Chemotherapy and Radiotherapy

Part III

 

Chapter 1

How to Cope with the Side Effects 

Three Types of Side Effects

    In general, side effects from chemotherapy and radiotherapy can be divided into three types. The first is a set of physiological responses, which are acute and the least concerning, including appetite loss, nausea and vomiting, weakness and fatigue, as well as flu-like symptoms; all of these can be managed by specific actions.

Fig. 3.1  Common cell types in a cell renewal system 

The second type of side effects is more severe and may damage cells in renewal tissues. There are a number of such cell renewal tissues in the body encompassing the hematopoietic system, the gastrointestinal tract, skin, hair, gonads, and cornea. Fig. 3.1 shows the common cell types in a cell types in a cell renewal system. The first and basic cell type is the stem cell – destroy all of these and the tissue gradually disappears. These cells are especially sensitive to both radiation and chemotherapeutic agents, and more so when they are proliferating. If over 99.9% of the stem cells are destroyed, the renewal tissue can’t recover by itself and the host will die. If stem cells are not totally destroyed, stem cell transplant and some protective agents can ameliorate some of the damage. The “committed” stem cells and differentiating cells (which may require proliferation) are also sensitive to chemotherapy and radiotherapy since they are proliferating just like the cancer cells. Finally, the differentiated cells such as platelets and red blood cells are resistant to chemotherapy. However, since the differentiated cells have a specific half-life, they are “used up” and may not be replaced as the stem cells and differentiating precursor cells have been destroyed. 

The third type of side effects is direct damage to cells in major organs such as liver, heart, and brain. These are non-proliferating cells, and like the differentiated cells discussed above and relatively insensitive. However, some drugs do have selective toxicity to specific organs such as anthracyclines and cardiac toxicity.

© Jiajiu Shaw, 2021

Disclaimer: This blog is written solely for informational purposes. It does not constitute the practice of any medical, nursing or other medical professional health care advice, diagnosis, or treatment. All contents posted are extracted from the book, "SIDE EFFECTS OF CHEMOTHERAPY AND RADIOTHERAPY", prepared by Dr. Jiajiu Shaw, Dr. Frederick Valeriote, and Dr. Ben Chen. 

Chemotherapy and Its Side Effects: Chapter 3 - Side Effects of Chemotherapy

D. Other Side Effects

D.1. Liver damage

Liver is a vital organ and has a wide range of functions. Liver produces bile to aid in digestion through the emulsification of lipids and plays a major role in metabolism. Other functions of liver include hormone production, decomposition of red blood cells (RBCs), plasma protein synthesis, and detoxification of small and complex molecules.

Theoretically, all drugs are associated with certain toxicity (but to different extents) and liver is the major organ that is supposed to “detoxify” the drugs mainly by breaking down the drugs into metabolite(s). The other way for liver to make a drug less toxic is to make it more water soluble, thus more easily excreted out of the body and reduce potential toxicity. However, a small percentage of drugs are able to evade the “protection mechanism” by the liver. In this case, the drugs pass through the body’s major detoxifying guard (liver), damage liver, and move to other organs to exert other side effects.

A typical example of anticancer drugs with potential liver toxicity is cisplatin. Tyrosine kinase inhibitors are also associated with potential liver toxicity. Recently, the FDA required a “black box warnings” to be included on labels of several anticancer drugs to indicate the increased risk of liver injury including some tyrosine kinase inhibitors.

© Jiajiu Shaw, 2020

Disclaimer: This blog is written solely for informational purposes. It does not constitute the practice of any medical, nursing or other medical professional health care advice, diagnosis, or treatment. All contents posted are extracted from the book, "SIDE EFFECTS OF CHEMOTHERAPY AND RADIOTHERAPY", prepared by Dr. Jiajiu Shaw, Dr. Frederick Valeriote, and Dr. Ben Chen.

Chemotherapy and Its Side Effects: Chapter 2 - Alkylating Agents (Cont'd)

A.1. Nitrogen mustards

One of the first alkylating agents was nitrogen mustard, NH2 (Fig. 1.1). Nitrogen mustards are alkylating agents but are not specific in their binding site. The utility of nitrogen mustards is limited because they are very reactive and consequently very short lived.

Because of its excessive toxicity, the original nitrogen mustard, NH2, is not often used nowadays. Instead, some of its analogs or derivatives, such as cyclophosphamide, are being used.

© Jiajiu Shaw, 2018

Disclaimer: This blog is written solely for informational purposes. It does not constitute the practice of any medical, nursing or other medical professional health care advice, diagnosis, or treatment. All contents posted are extracted from the book, "SIDE EFFECTS OF CHEMOTHERAPY AND RADIOTHERAPY", prepared by Dr. Jiajiu Shaw, Dr. Frederick Valeriote, and Dr. Ben Chen.