Side effects of cancer drugs
Some cancer drugs may cause you to feel or be sick. But there are treatments that can help and ways you can support yourself.
There are many different types of cancer drugs. Some of them may make you feel sick.
If a drug can cause sickness, it doesn't mean it will make you sick. Everyone reacts differently. All cancer drugs have side effects, but they don’t affect everyone.
The reasons why drugs cause sickness are complex. Sickness and being sick involve processes in the:
brain and spinal cord (central nervous system)
stomach
small bowel
It's not possible to tell in advance who will feel or be sick or how bad it will be. It can depend on:
the drug or combination of drugs you are having
the dose
how you react to the drug
how you reacted to drug treatment in the past
Drugs that can cause sickness include:
chemotherapy drugs
targeted cancer drugs
immunotherapy
hormone therapies
bisphosphonates
painkillers
Sickness caused by some chemotherapy drugs is the most difficult side effect for many people. Uncontrolled sickness can affect your quality of life on many levels.
But not all chemotherapy drugs make you sick. If they do, it generally starts from a few minutes to several hours after having the drug. With some drugs, the sickness lasts for a few hours, or until the next day. Sometimes it can last for several days.
There are risk factors for sickness caused by chemotherapy. You are more likely to feel sick if you:
are female
are younger than 60
have a first cycle of chemotherapy
have a history of being sick on previous chemotherapy
have a history of feeling sick and being sick such as motion sickness or sickness during pregnancy
feel and are sick before chemotherapy starts, also called anticipatory nausea and vomiting
Other risk factors are the:
type of chemotherapy, for example, platinum or anthracycline chemotherapy
dose
rate at which you have it
route through which you have it
Let your doctor, nurse or pharmacist know if you are struggling with sickness while having chemotherapy drugs. There are several different anti sickness medicines they can prescribe.
Some targeted cancer drugs, and immunotherapy can make you feel or be sick. Doctors are still learning about the possible side effects of newer drugs.
Hormone therapies, bisphosphonates or painkillers, can make you feel sick when you first start taking them. This might wear off within days or weeks. It’s possible to have longer-term sickness, particularly with stronger painkillers.
Doctors usually control sickness well with anti sickness drugs (anti emetics). Your team will prescribe them if your cancer treatment is likely to make you feel or be sick.
You have anti sickness drugs as a tablet or an injection or drip through a vein. You usually take them at home an hour before your treatment starts. Or the nurse will give it to you before you have cancer drugs. In some situations, you can have anti sickness through a patch that sticks on your skin. This lasts for a few days. You might also take anti sickness tablets home for a few days after chemotherapy.
When having chemotherapy, the type of anti sickness drug you have might depend on:
the type and dose of chemotherapy you’re having
how you are having the chemotherapy drug, for example, by mouth or through a vein
how likely it is that the chemotherapy drug would cause you to feel sick (minimal, low, moderate or high risk)
There are many different anti sickness drugs. So, if one doesn’t work for you, your doctor or nurse can prescribe another one to try. Some of the drugs used mostly are:
5HT3 receptor antagonists (ondansetron, granisetron or palonosetron)
NK1 receptor antagonists (aprepitant, fosaprepitant or rolapitant)
netupitant and palonosetron combined (Akynzeo)
corticosteroids (dexamethasone)
dopamine receptor antagonists (metoclopramide)
antihistamines (cyclizine)
olanzapine
Doctors sometimes use anti anxiety medicines like benzodiazepines to control sickness. This can be, for example, when someone feels sick because they are anxious about having a chemotherapy drug.
In some people, chemotherapy sickness does not improve with anti sickness drugs. In these situations, doctors can use a drug called nabilone. Nabilone is a man made (synthetic) form of cannabis. You might have to stay in hospital to have nabilone.
Take your anti sickness drugs regularly, whether you feel sick or not. The drugs are much better at preventing sickness than stopping it once it starts.
The following methods can be helpful to help control sickness. Use them in combination with anti sickness drugs:
acupuncture or acupressure
cognitive behavioural therapy (CBT)
distraction, for example, playing video games or listening to music
guided imagery
yoga
muscle relaxation training
exercise
hypnosis
If a drug causes your sickness, you could try some of the following tips:
Avoid eating or preparing food when you feel sick.
Avoid fried foods, fatty foods or foods with a strong smell.
Eat cold or slightly warm food if the smell of cooked or cooking food makes you feel sick.
Eat several small meals and snacks each day and chew your food well.
Drink plenty to stop you from becoming dehydrated, but avoid filling your stomach with a large amount of liquid before eating.
Fizzy drinks can help some people with nausea.
Use relaxation techniques to help control sickness.
Try crystallised stem ginger, ginger tea or ginger ale.
Try orange flavoured ice lollies.
Eat bananas to replace potassium in your blood, which can drop if you vomit.
If you are sick after chemotherapy you could also try the following:
Drinking high calorie drinks might be easier than eating, ask your doctor or nurse about these
Have a small meal a few hours before chemotherapy, not just before
Avoid your favourite foods when having chemotherapy as you might associate them with treatment
Read more tips on what you can do to help you cope with sickness
People react differently to cancer drugs. Here are some stories from cancer patients:
Last reviewed: 25 May 2023
Next review due: 25 May 2026
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