Medicines Used to Treat Nausea and Vomiting

It is important to control nausea and vomiting as much as possible. These symptoms can affect your daily life, and mental and physical health. Nausea and vomiting can cause cancer treatment delays and make it hard for you to continue treatment. Relieving these side effects can help you better deal with your treatments and keep them on schedule.

Many medicines are used to help prevent and control nausea and vomiting. Which ones you get will depend on how likely your treatment is to cause nausea and vomiting and how the medicines worked for you during past treatment.

Types of anti-nausea and vomiting medicines (anti-emetics)

There are different pathways in your body that can cause nausea and vomiting. Some of these pathways are in the brain while others are in the digestive tract (esophagus, stomach, and intestines). Which pathways are affected depends on the treatment you are getting. Anti-emetics help block these pathways.

Anti-emetic medicines are grouped by how they work in the body to prevent nausea and vomiting. Each group of medicines works in a different way. They are often combined to be most effective.

The following anti-emetics are the ones used most often to prevent and treat nausea and vomiting.

Serotonin (5-HT3) antagonists (examples include ondansetron, granisetron, dolasetron, and palonosetron)

• Work best when given on a schedule before and during chemo treatment.
• Don’t make you sleepy but might cause headache and constipation.

NK-1 receptor antagonists (examples include aprepitant, rolapitant, fosaprepitant, and netupitant)

• Work best to prevent, not treat, nausea and vomiting.
• Most helpful in preventing delayed nausea and vomiting.

Steroids (Dexamethasone is the steroid used most often for nausea and vomiting).

• Most often given with other anti-emetic medicines to better prevent nausea and vomiting. Can cause indigestion so should be taken with food.
• Best taken in the morning as they can make it harder to go to sleep at night.
• Can cause hiccups and increase blood sugar. People with diabetes might need to watch their blood sugar more closely.

Olanzapine  

• Has been shown to be helpful with nausea and vomiting, especially when given with other anti-nausea and vomiting medicines.
• Can make you sleepy.

Benzodiazepines (examples include lorazepam and alprazolam)

• Can help to manage nausea and vomiting by helping you feel calmer, more relaxed, and less anxious.
• Used most often for anticipatory or breakthrough nausea and vomiting.

Combination anti-nausea medicines

• Include more than one type of anti-emetic in one dose.
• For example, you can get a combination of a serotonin (5-HT3) antagonist with a NK-1 receptor antagonist. This combination is meant to help with both acute and delayed nausea and vomiting.

Sometimes, the more commonly used anti-emetics don’t control nausea and vomiting well. So, other medicines might be tried. These medicines might also be used for treatments that are less likely to cause nausea and vomiting. Examples include:

• Phenothiazines such as prochlorperazine and promethazine
• Metoclopramide
• Haloperidol
• Cannabinoids such as dronabinol, nabilone

Many anti-emetics have side effects. Many can make you sleepy and make it more likely that you will fall. Talk to your doctor or cancer care team about what side effects you might have from the anti-emetics.  

How are anti-emetics medicines given?

There are many ways to take anti-emetic medicines. Most often they are given through an IV (intravenously), by mouth as a pill or liquid, or as a tablet that dissolves under your tongue. Sometimes anti-emetics may also be given as a patch that sticks to your skin or as a suppository.

Your cancer care team will think about the following things when choosing the best way to give you anti-emetics.

• How likely it is that your cancer treatment will cause nausea and vomiting
• How bad your nausea and/or vomiting is  
• The easiest way for you to take the medicine  
• What you prefer  
• Whether you need a medicine that lasts for a longer period (such as for preventing nausea and vomiting) or a medicine that works quickly (such as for breakthrough pain).
• Your medical insurance coverage and cost of the medicine

If the medicines used first don’t work, your doctor can switch you to another medicine or add a new one. Another option is to give the medicines in a different way (by a different route).

Taking pills by mouth is often the best, easiest, and cheapest way to prevent nausea and vomiting. But if you’re already vomiting, or you can’t swallow and keep things down, the medicine might need to be given another way, such as by a patch or into a vein.

Let your cancer care team know if you are still having nausea and vomiting even with an anti-emetic treatment. There are many options and other medicines or ways of giving them might work better for you. Don’t let nausea and vomiting keep you from being able to eat and drink. There are many medicines that can be used to prevent and treat these side effects.

Cost of anti-emetics

Medicines used to prevent and treat nausea and vomiting can be expensive. The cost to you will depend on:

• Whether you have prescription insurance and how much of the cost it covers
• Whether you are given a brand name or generic medicine (if available)
• How the anti-emetic is given (pill or liquid you swallow, by IV, or a patch on your skin)

You might need to get pre-approval from your health insurance or prescription plan before your anti-emetics will be covered.  Ask your cancer care team about the cost of these medicines, what your options are, how many pills you might need during treatment, and what you might have to pay out of pocket.

How does my cancer care team know what anti-emetics to give to me?

Cancer treatments are grouped by how likely they are to cause nausea or vomiting (emetogenic potential).

• High risk: 9 in 10 people will have nausea and vomiting
• Moderate risk: 3 to 9 in10 people will have nausea and vomiting
• Low risk: 1 to 3 in10 people will have nausea and vomiting
• Minimal risk: Less than 1 in10 people will have nausea and vomiting

Treatment to prevent or manage nausea and vomiting is based on this risk. The goal is to prevent nausea and vomiting as much as possible. You will likely need to take more than one medicine to manage this symptom.

Treating nausea and vomiting caused by cancer medicines

The anti-emetic medicine you get depends on how likely your treatment is to cause nausea and vomiting. No one medicine can prevent or control nausea and vomiting all the time. People often get more than one type of anti-emetic since they block different causes of nausea and vomiting.

Your cancer care team will look at a number of factors when choosing the best plan to help prevent and manage nausea and vomiting with your treatment. They will:

• Look at how likely it is you will have nausea and vomiting during your cancer treatment
• Look at guidelines and research to see what anti-nausea medicines are recommended
• Ask about your history of nausea and vomiting
• Ask how well any anti-nausea medicines have worked for you before
• Look at side effects of the anti-emetics
• Make changes as needed to help keep you from having nausea and vomiting

It’s easier to prevent nausea and vomiting than stop it once it starts. That is why anti-nausea and vomiting medicines are often given on a regular schedule around the clock. Your cancer care team might tell you to take the medicines on a schedule even if you don't have any nausea or vomiting.

Sometimes, you may take the medicine on an "as needed" schedule. This means you take the medicine at the first sign of nausea to keep it from getting worse. Ask your cancer care team how you should take these medicines.

• Medicines to prevent nausea and vomiting should start before the treatment is given.
• Anti-emetics should continue as long as the cancer treatment is likely to cause nausea and vomiting. This can be different based on the treatment plan and medicines given.

Each time you start a new cycle of chemo, be sure to tell your cancer care team what did and didn’t work the last time.

Treating nausea and vomiting caused by radiation therapy

If your radiation treatment is likely to cause nausea and vomiting, your cancer care team will give you medicines to help prevent it. Anti-nausea and vomiting medicines may be given by mouth, into a vein, or both.

Your cancer care team will look at several things when choosing the best plan to help prevent and manage nausea and vomiting.  

• How likely your radiation treatment is to cause nausea and vomiting
• Your history of nausea and vomiting
• How well any anti-nausea medicines have worked for you before
• Side effects of the anti-nausea medicines

They will then make changes as needed to help keep you from having nausea and vomiting

Anti-nausea and vomiting medicines are often given on a regular schedule around the clock. Your cancer care team may tell you to take the medicines on schedule even if you don’t have any nausea or vomiting.

Sometimes, you may take the medicine "as needed” . This means you take the medicine at the first sign of nausea to keep it from getting worse. Ask your cancer care team the best way to take your anti-nausea and vomiting medicines.