Nausea is an uneasy feeling in the stomach that may lead to vomiting. It is a common side effect or symptom from different illnesses, medications and treatments such as chemotherapy.
What causes nausea and vomiting?
Nausea and vomiting are quite common after chemotherapy. Some chemotherapy regimens have a higher chance of patients experiencing nausea and vomiting. Some immunotherapies or sometimes radiotherapy can cause these symptoms. The specialists are getting better at preventing and/or treating, what can be called ‘chemotherapy induced nausea and vomiting’.
Nausea and vomiting can sometimes occur within a few hours after the chemotherapy has started or after the treatment has finished. It can also happen for some people when they wake up on the day before having their treatment, especially if they had these symptoms the previous cycle.
Vomiting is triggered from a spot in the brain called the vomiting centre. There are several signals that can make the vomiting centre cause a person to vomit.
These may include:
- Signals from an area in the brain called the chemo-receptor trigger zone that reacts to chemicals or drugs in the blood
- Signals from the brain cortex and limbic system that reacts to sight, taste, and smell, as well as to emotions and pain
- Signals from some other organs and nerves that respond to disease or irritation in these organs. In chemotherapy, it has been noted that there are areas in the stomach, oesophagus and intestines that are triggered.
Preventing nausea and vomiting
The doctor can order anti-nausea medication prior to treatment and this can be in the form of a tablet or the nurse will put this into the IV before starting treatment. Once these are given some is allowed for the medications to start taking effect before treatment starts.
It is often good to ensure that on the day of treatment food has been eaten as this will help with how the stomach feels. It is also important to drink plenty of fluids, especially in the days leading up to treatment. Dehydration can cause nausea and then it is hard to keep up with fluids.
It is very important that the medication to be taken at home after treatment is taken as advised by the doctor, the pharmacist or nurse, even if nausea isn’t present. This is to keep the nausea away, which is better than trying to treat nausea once it starts.
The medication that is prescribed is what works best for most people. Sometimes a different medication may be needed. Contact the medical team if nausea and vomiting is not controlled. The treating team can sometimes send a prescription to your local pharmacy if a different medication is needed.
Why is it important to prevent nausea & vomiting?
It is important to prevent or stop nausea and vomiting. This will help prevent dehydration and signs of dehydration can include:
- Feeling dizzy or lightheaded
- Severe headache
- Heart feels like it is racing or fast heartbeat
- Dry mouth
- Less urine and it is darker in colour
Coping with nausea and vomiting
There are some things that may help.
- Eat a light and bland diet. Avoid strong smelling food
- Eat small amounts of food throughout the day
- Avoid heavy, high fat and greasy meals
- Wear loose-fitting clothes
- Avoid caffeine and smoking
- Drink plenty of fluid. Avoid hot drinks. Drink through a straw so the taste buds are bypassed. Fizzy drinks such as ginger ale can help settle the stomach
- Suck on hard lollies, ice blocks or ice during chemotherapy
- Identify and avoid triggers that make you sick.
- Talk to the health care team about your nausea
- Relax before and after treatment. Try things such as meditation and gentle breathing exercises
- Contact your health care team if you vomit more than 4-5 times in 24 hours
Treatment for nausea and vomiting
- Corticosteroids: are related to the natural hormone cortisol. Been used for many years. An example is dexamethasone
Serotonin antagonists: these drugs stop serotonin from sending a signal that causes vomiting. Examples are palonosetron, ondansetron and granisetron
- Dopamine antagonists: Examples are metoclopramide and prochlorperazine. Often prescribed for breakthrough nausea and vomiting
- NK-1 Inhibitors: It blocks the action of a peptide that triggers the nausea and vomiting reflexes. An example is Aprepitant (Emend)
- Anti-anxiety drugs: They block nausea and vomiting. Examples are ativan and valium.
Many patients who experience nausea and vomiting after chemotherapy develop anticipatory symptoms in the chemotherapy cycles that follow. This means patients can have these symptoms before they come into the hospital for treatment. Some report feeling nausea from a day or so before treatment or wake up on the day of treatment reporting feeling nausea or vomiting.
Anticipatory nausea and vomiting occurs in around 1 in every 3 patients and around 1 in every 10 people will experience anticipatory vomiting. It generally occurs in patients who experience uncontrolled nausea and vomiting after prior chemotherapy treatments.
Cause of anticipatory nausea
Anticipatory nausea and vomiting is thought to be a result of classical psychological conditioning. The sights sounds and smells of the chemotherapy room create a learned response once they associate the treatment area with nausea and vomiting. This becomes a pattern. There are some patients who are at a higher risk who include:
- Being young than 50 years or female
- Experiencing nausea and vomiting after a prior chemotherapy session
- Experiencing high levels of anxiety in reaction to specific situations
- Susceptible to travel sickness
- Those who experienced morning sickness during pregnancy
Prevention and treatment
The best thing is to prevent nausea and vomiting from the first cycle. The better the experience the less likely it will happen in future cycles.
Anticipatory nausea needs to be reported to the doctor or treating nurse. They can prescribe medications to help relax the patient before treatment starts. These medications can be taken home and be taken prior to coming in for the next treatment. The most common drug used is lorazepam (Ativan).
Other things to try is distraction, bring things to do during treatment or request a quieter area in the treatment area (if possible).