It's common to feel sick to your stomach (nauseated) or to vomit when you get chemotherapy. Nausea and vomiting are caused by cancer drugs you may get during treatment. You may feel sick or vomit soon after your treatment session. But with some chemotherapy medicines, you may not get sick until days later. Some people have only nausea or only vomiting. Others have both. Some people don't get sick at all from chemotherapy.
There are many drugs that can prevent nausea and vomiting. Preventing nausea and vomiting will help calm your stomach so you can eat, stay strong, and give your body a chance to rest between cancer treatments.
Antinausea drugs work best if you start taking them before you start chemotherapy.
What causes nausea and vomiting?
Doctors believe that some drugs can affect the nervous system or irritate your stomach lining and make you feel sick. This may cause nausea and vomiting.
How big a dose you get can also affect how you feel. A drug may be fine at a low dose. At a higher dose, it may make you sick. But that higher dose may be what's needed to kill cancer cells.
The way you receive a drug can also make a difference. A drug that is given through your vein in an IV may make you feel sick sooner than the same drug given as a pill. That's because your body will absorb the IV drug faster.
What will increase your risk for nausea and vomiting?
There are more than 100 different drugs to treat cancer. Some are much more likely to cause nausea and vomiting than others. You and your doctor will decide which cancer drugs you will get based on the type of cancer you have, where the cancer is in your body, and how serious the cancer is (its stage).
Other things besides cancer drugs can raise your risk for nausea and vomiting. If you had chemotherapy before and it led to vomiting, your brain will remember it. So just thinking about your cancer treatment can make you feel sick. This is called anticipatory nausea and vomiting. Antinausea medicines don't work well for anticipatory nausea or vomiting, but other methods that relax or distract you may help. These methods include progressive muscle relaxation, hypnosis, acupuncture, or distraction with music or video or mobile games.
How are nausea and vomiting treated?
The goal of treatment is to prevent nausea and vomiting. Your doctor will look at which cancer drugs you are taking and your history of getting sick. You will probably be given a medicine that works to control nausea and vomiting in other people who are getting the same cancer treatment. You may be given two or three medicines to take.
Antinausea medicines are usually taken as pills. But you might also get them through an IV or as a patch that's taped to your skin. These medicines are usually given before your first chemotherapy session. You will need to take antinausea medicine as long as your cancer treatments last.
Some of the most common medicines used to control nausea and vomiting include:
- Dopamine antagonists, such as metoclopramide and phenothiazines.
- Serotonin antagonists, such as granisetron, ondansetron, and palonosetron.
- Other antagonists. These include:
- Corticosteroids, such as dexamethasone and methylprednisolone.
- Benzodiazepines, such as alprazolam, lorazepam, and midazolam.
Medical marijuana is legal in some areas and may be used to control nausea. Other man-made forms of marijuana, such as dronabinol (Marinol) and nabilone (Cesamet), may also used to treat nausea and vomiting in some people when other medicines don't work.
The best way to prevent nausea and vomiting is to start taking antinausea medicine well before you begin your cancer treatment. But even if you have already started cancer treatment, it's not too late to try to prevent nausea and vomiting. Talk with your doctor if chemotherapy is making you sick.
How do antinausea medicines work?
These medicines work in different ways. Some block a chemical in the brain that controls vomiting. Other drugs reduce swelling in the part of the brain that controls nausea. A few drugs slow down the central nervous system. Some of these drugs work alone. Others only work when you take them with other drugs.
Some antinausea medicines cause side effects. You may:
- Feel sleepy or confused.
- Have headaches.
- Have diarrhea or constipation.
- Have hiccups.
- Feel weak and very tired.
- Twitch or have muscle spasms.
Not all antinausea medicines work the same for everyone. You might have to try a few of these drugs, alone and together, to find what works best for you. After you start to take antinausea medicines, tell your doctor right away if you still feel sick.
What else can you do to manage nausea and vomiting?
In addition to antinausea medicines, you can try some things at home to help yourself feel better. If you're feeling sick, eat several small meals during the day instead of a few large meals. Stay away from sweet, fried, or fatty foods. Suck on ice cubes or mints. For more information, see: