Chemotherapy side effects

Each chemotherapy drug or combination has its own side effects. Most side effects can be easily controlled by medicines. Not everyone will have the same side effects. Your healthcare team will give you information about the side effects that are most likely to affect you. You might find it helpful to keep a note of any that you experience.

Common side effects include: 

• Diarrhoea 
• Increased risk of infection
• A sore mouth
• Feeling and being sick 

Increased risk of infection

Chemotherapy can reduce the number of white blood cells called neutrophils, which help fight infection. If you have a low number of these cells it’s known as neutropenia.

You can help to protect yourself from infection by washing your hands with soap regularly and avoiding contact with people who have an infection such as a cold or flu.

You should be given information about infections by your chemotherapy team. If you think you might have an infection, you should contact your medical team as soon as possible.

Managing side effects through diet 

Chemotherapy can affect your ability to eat and enjoy food in different ways. Some people experience side effects briefly or temporarily, others may be affected more seriously and really struggle to enjoy their food. You might find you have a decreased appetite, an altered sense of taste and smell, a sore mouth or throat, and you may become more sensitive to hot and cold food and drink. 

• If you are feeling or being sick (nausea and vomiting)

Try eating dry food like toast or crackers, eat small portions with plenty of fluids and avoid greasy, fatty or fried foods.

• If you have a sore mouth

Drink plenty of nourishing fluids, such as fruit smoothies or milkshakes, try cold foods and drinks like ice cream or jelly. Avoid salty, spiced or rough edged foods.

• If you have a dry mouth

Take frequent sips of drinks, try ice lollies, chewing gum and foods with sauce or gravy. Avoid sticky or dry foods.

You can find more detailed information about diet with and beyond bowel cancer in our Eating well information booklet. 

Side effects to specific chemotherapy drugs 

Fluorouracil (5FU)

Having fluorouracil (or fluorouracil based drugs) can sometimes affect the way your heart works. You might have tests to check how your heart is working. If you have any existing heart problems you should let your medical team know. If you have any chest pain or tightness, contact a doctor as soon as possible.

Some patients have DPD deficiency. This is rare but can cause serious reactions to fluorouracil. Read more about DPD deficiency below.

Capecitabine (Xeloda®)

Some people who take capecitabine have a skin reaction on their hands and feet called hand-foot syndrome (also known as palmar-plantar). Symptoms include sore hands and feet, which can go red and peel. It might help to keep your hands and feet cool and avoid hot water. Some people find avoiding wearing tightly fitting gloves also helps. Your medical team can give you medicines and creams to help you treat and control this.

Some patients have DPD deficiency. This is rare but can cause serious reactions to capecitabine. Read more about DPD deficiency below.

Irinotecan (Campto®)

Some people have a reaction within 24 hours of taking the chemotherapy drug irinotecan. This is referred to as ‘acute cholinergic syndrome’. Symptoms include diarrhoea, stomach pain, producing a lot of saliva and sweating more than usual. These symptoms can be easily treated. Tell your medical team if you have any of these symptoms.

Oxaliplatin (Eloxatin®)

You might have tingling or numbness in your hands and feet. This is called peripheral neuropathy. Talk to your medical team if you have these symptoms.

You may get pins and needles, weakness or numbness. This can make it hard to do everyday things like writing, picking up small items and walking. These symptoms can be triggered or made worse by the cold. Your healthcare team may advise you to wear gloves when you use the fridge or freezer and avoid chilled food or drinks for a few days after each treatment.

You may get neuropathy symptoms during your chemotherapy cycle and for up to two weeks afterwards. Symptoms may improve once you finish treatment but in some people, neuropathy can last for months or years after treatment.

Tell your healthcare team if you have any symptoms of neuropathy. If the symptoms are affecting your daily life, your doctor may suggest lowering the dose of oxaliplatin or changing your treatment.

DPD deficiency

Some patients have a rare, but serious reaction to the chemotherapy drugs capecitabine or fluorouracil (also known as 5FU). In some cases this can be life threatening and even fatal. The reaction is linked to a protein called DPD (which stands for dihydropyrimide dehydrogenase). Some people have low or no levels of this protein in their body. This is known as DPD deficiency. This is because some people have variations in a gene called DPYD. You won’t usually know you have variations in your DPYD gene unless you have these types of chemotherapy.

DPD helps the body to break down capecitabine or 5FU. If a person has a DPD deficiency, these chemotherapy drugs can build up in the body. This can lead to severe reactions. In many cases, capecitabine or 5FU can still be given safely to patients with DPD deficiency by reducing the dose of these drugs. However, for patients with very severe deficiency or no DPD at all, different chemotherapy treatment may need to be given.

England, Wales and Northern Ireland are routinely testing all cancer patients who are going to be treated with certain types of chemotherapy to find out if they have a higher risk of having a severe side effect. This is called the DPYD test. The Scottish Government has committed to introducing DPYD testing in Scotland in the future.

You should speak to your medical team if you are worried about DPD deficiency. They might be able to offer you a test. You can find out more on the Cancer Research UK website.

Updated October 2020