Nausea and Vomiting

Nausea and vomiting are common side effects of cancer and cancer treatments. Symptoms can vary from mild to severe and may occur before, during, or after treatment. Pediatric cancer patients and families often report that nausea is one of the side effects that bothers them most. If not managed, nausea and vomiting can have a negative effect on emotional well-being, hinder treatment compliance, interfere with daily activities, and lead to poor nutrition, weight loss and other health complications.

For most children with cancer, there are effective ways to reduce nausea and vomiting. These include nausea medicines, changes in diet, and coping strategies such as deep breathing and distraction. Complementary therapies such as acupuncture, aromatherapy, and hypnosis may also be effective.

Families may see or hear the term “emesis” during cancer care. Emesis is the clinical name for vomiting. Antiemetic drugs are medicines used to treat nausea and vomiting.

What Is Nausea?

Nausea is the feeling of sickness or discomfort that a person associates with the urge to vomit. Nausea is subjective, meaning that it depends on the person’s own experience. Nausea usually involves unpleasant sensations in the throat, esophagus, or stomach. Other sensations a person may relate to nausea are dizziness, trouble swallowing, sweating, and feeling chilled or flushed.

What is Vomiting?

Vomiting, or throwing up, occurs due to the action of the diaphragm and abdominal muscles. These muscles contract and push stomach contents up the esophagus and out the mouth. This is regulated by nerves that respond to certain triggers. Common triggers for nausea and vomiting are viruses and bacteria, motion, and physical or chemical signals. These activate nerve pathways that control the vomiting reflex.

Nausea and vomiting are related, but each may occur without the other.

Causes of Nausea and Vomiting in Children with Cancer

Chemotherapy is a main cause of nausea in children with cancer. However, radiation therapy and other medicines can also trigger feelings of nausea. Some children have nausea due to the effects of cancer itself or because of other health problems. Children with brain tumors may have hydrocephalus, a build-up of fluid in the brain. The increased pressure can trigger nerves that cause vomiting.

Common causes of nausea and vomiting in children with cancer include:

• Chemotherapy
• Other medicines including antibiotics, opioid medicines, and anti-seizure drugs
• Radiation therapy
• The cancer itself, especially if the tumor affects the brain or digestive system
• Disorders of the stomach and digestive tract
• Inner ear problems
• Hormone and metabolic imbalances
• Fever and infection
• Stress and anxiety
• Pain
• Previous vomiting

Nausea and vomiting are caused by a complex interaction among several body systems including the autonomic nervous system, central nervous system, endocrine system, and digestive system. Thoughts and emotions also play an important role in nausea and vomiting.

Nausea and Vomiting During Chemotherapy

Up to 70% of children who get chemotherapy will experience nausea at some point during treatment. Symptoms vary from mild stomach upset to severe vomiting. There are 3 types of nausea and vomiting (emesis) associated with chemotherapy:

1. Acute Emesis – occurs during the first 24 hours after chemotherapy. It usually begins 1-2 hours after chemotherapy and starts to get better after 4-6 hours.
2. Delayed Emesis – develops after 24 hours. Usually, delayed emesis is most severe 48-72 hours after chemotherapy and then gets better over the next few days.
3. Anticipatory Emesis – develops before chemotherapy and is brought on by triggers that the person associates with chemotherapy. This is a learned response and is most common in patients who had episodes of severe nausea and vomiting with past treatments.

Chemotherapy medicines can be classified by their risk or likelihood of causing nausea and vomiting:

• High (>90% risk)
• Moderate (30-90% risk)
• Low (10-30% risk)
• Minimal (<10% risk)

These categories are based on the likelihood of symptoms if no anti-nausea medicines are given. Children receiving chemotherapy with high or moderate risk of vomiting are usually given medicines to prevent nausea and vomiting before symptoms occur.

What Cancer Medicines Cause Nausea and Vomiting?

Why Does Chemotherapy Cause Nausea and Vomiting?

Nausea and vomiting with chemotherapy is not fully understood. However, chemotherapy may cause the release of certain neurotransmitters that regulate nausea and vomiting. Neurotransmitters including dopamine, serotonin, and substance P act as chemical signals in the areas of the brain that control nausea and vomiting. Some anti-nausea medicines act on these neurotransmitter systems to block the signals.

How to Treat Nausea and Vomiting in Children

There are several ways to help manage nausea and vomiting during cancer treatment. It is important for families to work closely with the care team to make sure that children’s symptoms are managed.

Medicines for Nausea

Nausea medicines (antiemetics) may be used to prevent and treat nausea and vomiting. Common medicines used in pediatric cancer patients include:

• Ondansetron (Zofran®)
• Granisetron (Kytril®)
• Lorazepam (Ativan®)
• Diphenhydramine (Benadryl®)
• Dexamethasone (Decadron®, Dexamethasone Intensol®, Dexpak®)
• Aprepitant (Emend®)
• Metoclopramide (Reglan®)
• Olanzapine (Zyprexa®)
• Scopolamine (Transderm Scop®)

Some patients will receive a combination of medicines. Many of the medicines used to reduce nausea and vomiting have other uses. Families should always talk with their doctor or pharmacist to know the purpose and dosing instructions for each drug their child is taking.

Doctors prescribe nausea medicines based on the chemotherapy plan, age of the child, type of cancer, and other patient factors. Some patients will be prescribed medicine before the start of chemotherapy. However, nausea medicines are also prescribed as needed. It is very important for families to discuss symptoms with the care team so that nausea and vomiting can be managed in the best way possible.

Changes in Diet to Help with Nausea

Certain foods and smells may make nausea worse. Many patients lose their appetite during cancer treatment. Children can be very different in what they are able eat when they don’t feel well. It may take some trial and error to find what works best. Some general tips are:

• Eat small snacks and meals.
• Eat and drink slowly.
• Avoid having liquids with meals.
• Offer dry, bland foods such as crackers or toast.
• Avoid spicy, acidic, or rich foods.
• Eat in a place that does not have strong smells.
• Allow the child to choose when and what to eat.

Find more nutrition tips for patients with nausea and vomiting.

Nutrition professionals are important members of the care team, especially for children struggling with nausea and vomiting. A dietitian can help families find ways to address nutrition challenges. If children have severe nausea and vomiting, they might need to have a feeding tube (enteral nutrition) or receive IV nutrition (parenteral nutrition). These are important types of supportive care to encourage proper nutrition and hydration. Learn more about clinical nutrition in pediatric cancer care.

Other Strategies to Manage Nausea and Vomiting

A variety of coping strategies and complementary therapies that have been shown to help with nausea and vomiting. These include:

• Psychotherapy
• Biofeedback
• Deep breathing and relaxation techniques
• Hypnosis
• Acupuncture
• Acupressure
• Aromatherapy
• Herbal supplement - ginger
• Distraction (playing video games, art, music)
• Exercise

Families should talk with their care team before trying any complementary therapy to make sure that it is safe. The care team can also help families figure out what combination of therapies works best to manage symptoms.

Nausea and Vomiting in Children with Cancer: Tips for Families

• Talk to your care team about nausea and vomiting. There are medicines and other strategies that can help.
• Keep a record of symptoms. Write down when nausea occurs, what makes it worse, what makes it better, and any other symptoms such as pain, loss of appetite, diarrhea, or constipation. This can help you and your care team understand your symptoms and develop a plan.
• Let your care team know if your child is having problems eating or drinking. Nutrition support or IV fluids may be needed.
• Do not offer favorite foods when your child is nauseous. This food may become associated with feeling sick.
• Try chewing gum or sucking on hard candy, popsicles, or ice. 
• Avoid lying down flat after meals.
• Make sure to rinse the mouth after vomiting. Stomach acid can cause mouth irritation and tooth decay.
• Follow dosing instructions for nausea medicines. Make sure you refill the prescription before you run out.

More Resources on Nausea and Vomiting in Children with Cancer

• Nausea and Vomiting - Children's Oncology Group
• Nausea and Vomiting - St. Jude Children's Research Hospital
• Nausea and Vomiting Related to Cancer Treatment - National Cancer Institute