The most common chemotherapy side effects: Causes and advice 

Mirella Orsi

For the American Cancer Society estimated cancer prevalence in the United States as of January 1, 2009 is 12,549,000. Cancer prevalence is defined as the number of living people who have ever had a cancer diagnosis. It includes people diagnosed with cancer in the past as well those who were recently diagnosed.

Fortunately, we may say that, in the last years, the chemotherapy has made big steps forward. However, it has still a lot of side effects that make the therapy very hard to follow for the patients. Among these; nausea, vomiting and loss of appetite as the most common as the more annoying. During the chemotherapy, the druginduced nausea and vomiting may occur, so regularly that, anticipatory vomiting occurs, when patients return for treatment, before the chemotherapeutic agent is given. A research about the emesis from The National Cancer Institute at the national institute of health says that ”The prevalence of anticipatory nausea and vomiting (emesis) (ANV) has varied, owing to changing definitions and assessment methods. However, anticipatory nausea appears to occur in approximately 29% of patients receiving chemotherapy (about one of three patients), while anticipatory vomiting appears to occur in 11% of patients (about one of ten patients).With the introduction of new pharmacologic agents (5-HT3 receptor antagonists), it was anticipated that the prevalence of ANV might decline; however, studies have shown mixed results. One study found a lower incidence of ANV, and three studies found comparable incidence rates. It appears that the 5-HT3 agents reduce post-chemotherapy vomiting but not post-chemotherapy nausea, and the resulting impact on ANV is unclear.”

Sometimes these side effects can bring the patients to a syndrome of cachexia. About half of all cancer patients show a syndrome of cachexia, characterized by anorexia and loss of adipose tissue and skeletal muscle mass. Cachexia can have a profound impact on quality of life, symptom burden, and a patient’s sense of dignity. It is a very serious complication, as weight loss during cancer treatment is associated with more chemotherapy-related side effects; fewer completed cycles of chemotherapy, and decreased survival rates.
The physiologic mechanisms responsible for nausea and vomiting are not fully understood. However, it is clear that the coordination of the complex motor activity of the stomach and abdominal musculature takes place in the “vomiting center”. This centre, located in the reticular formation in the medulla, receives an input from the chemoreceptor trigger zone located on the floor of the fourth ventricle, the vestibular apparatus and other areas.The cancer chemotherapeutic agents like: alkylating agents, plant alkaloids and miscellaneous drugs stimulate the trigger zone, apparently through activation of dopamine and serotonin receptors.chemio
An anti-emetic agent is a drug that acts controlling vomiting and nausea. The anti-emetic drugs include: Phenothiazines, Metoclopramide, Ondansetron, Marijuana derivates and Corticosteroids. The first drugs block dopamine receptor in the chemoreceptor trigger zone as well as other areas of the brain. Metoclopramide also acts as a dopamine antagonist instead, the Ondansetron is a 5-HT3 inhibitor, and both of them are approved for use in the prevention of chemotherapy-induced and postoperative nausea and vomiting. Marijuana derivates are effective anti-emetics in some patients, including some in whom other anti-emetics are ineffective. The Corticosteroids, e.g. dexamethasone, are anti-emetics however their mechanism is unknown. In addition, we also have to considerate the effective anti-emetics of plants like Ginger (Zingiber officinale). In fact, powered ginger given in a dose of 2g is a strong anti-emetic, it is said to be better than Dinenhydrinate (Dramamine) the therapeutic dose of which is 100mg. The gingerols and shogaols are the compounds responsible for the anti-emetic effect. Homeopathy may be able to be an alternative comfort remedies during the chemotherapy. In fact, remedies like Phosphorus not only helps with the after-effects of general anaesthesia but may also help with side effects of chemotherapy. The Acupuncture and use of relaxation techniques show effective agonist these side effects.

Eating is an important part of maintaining your health during chemo cycle or radiation and side effects like nausea , vomiting and loss of appetite can be interfering with the recovery .Therefore, sometimes , using the appetite-stimulating is necessary.There are several widely used drugs which can cause a boost in appetite, including the 5-HT2C receptor antagonists/inverse agonists (e.g. Mirtazapine), Dopamine antagonists (e.g. Chlorpromazine), adrenergic antagonists (e.g. Propranolol) and Corticosteroids (e. g. Prednisone). Also we have to say that the appetite-stimulating effect of cannabis is documented in several cases.
In fact, the delta-9 tetrahydrocannabinol (THC), the main effective constituent of cannabis, was licensed as an anti-emetic drug in cancer patients receiving chemotherapy. There are also traditional appetite-stimulating like royal jelly that is a stimulant of appetite and of digestive functions. In conclusion , we can say that there are some useful advices to help to reduce these side effects like: avoid big meals, rest after eating, eat & drink slowly, refrain from eating in a warm room, eat your food cold or at room temperature , don’t lie down for a couple of hours after meals and eat frequent small meals.

Articles Published on ScienceCaffe– 05. 2013