Bevacizumab (Avastin) | Cancer Research UK
Cancer Research UK on Google+ Cancer Research UK on Facebook Cancer Research UK on Twitter

Bevacizumab (Avastin)

Nurse and patients talking about cancer

This page tells you about the biological therapy drug bevacizumab (Avastin) and its possible side effects. There are sections about


What bevacizumab is

Bevacizumab (pronounced bev-ah-siz-oo-mab) is a type of monoclonal antibody. Monoclonal antibodies are a type of biological therapy. It is also known by its brand name, Avastin. It is a treatment for

You may also have it as part of clinical trials for other types of cancer.

Bevacizumab targets a cancer cell protein called vascular endothelial growth factor (VEGF). This protein helps cancers to grow blood vessels, so they can get food and oxygen from the blood. All cancers need a blood supply to be able to survive and grow. Bevacizumab blocks this protein and stops the cancer from growing blood vessels, so it is starved and can't grow. Doctors call treatments that interfere with the development of a blood supply anti angiogenesis treatments.


How you have bevacizumab

You have bevacizumab through a drip into a vein. You may have it through a small tube put into the vein (cannula). Or you may have it through a central line, portacath or PICC line. These are long, plastic tubes that give the drugs directly into a large vein in your chest. You have the tube put in just before your course of treatment starts and it stays in place as long as you need it.

You have the first dose of bevacizumab over 90 minutes. If you don’t have any problems, the time can gradually be reduced to 30 minutes. 

For advanced bowel cancer or breast cancer, you may have bevacizumab every 2 weeks or every 3 weeks. 

For lung cancer or ovarian cancer you usually have it every 3 weeks, and for kidney cancer every 2 weeks.

The side effects associated with bevacizumab are listed below. The effects may be different if you are having it with other drugs. Click on the underlined links for information about coping with the side effects. If there is no link you can go to our cancer drug side effects section for general information or use the search box at the top of the page.


Common side effects

More than 10 in every 100 people have one or more of these.

  • High blood pressure occurs during treatment in about 1 in 4 people (25%) – your nurse or doctor will check your blood pressure regularly. Your doctor may start you on blood pressure tablets, increase your dose if you are already on them, or stop bevacizumab until your blood pressure is under control.
  • Feeling sick happens in about 2 out of 3 people (67%) but most people aren’t actually sick
  • Diarrhoea and abdominal pain – this can be severe in up to 1 in 3 people treated (32%)
  • Tiredness (fatigue) and weakness during and after treatment – most people find their energy levels start to improve when treatment ends
  • Pain and weakness affecting your joints, muscles, chest and abdomen
  • A drop in white blood cell count causing an increased risk of bacterial infection – infection may cause headaches, aching muscles, a cough, a sore throat, pain when passing urine, or may make you feel cold and shivery. Infections can sometimes be life threatening. You should urgently contact your treatment centre if you think you have an infection
  • Numbness or tingling in fingers and toes occurs in more than 1 in 10 people (10%) – this can cause difficulty with fiddly things such as doing up buttons. It may start within a few days or weeks and usually goes within a few months of finishing treatment
  • Slow wound healing – you won’t start on bevacizumab until at least 28 days after surgery or after any wounds have healed
  • Poor appetite
  • Constipation – drink plenty of fluids if you are constipated. Let your doctor or nurse know if you are constipated for more than 3 days
  • Irregular periods
  • Loss of fertility – you may not be able to become pregnant or father a child after having this drug. Talk to your doctor before starting treatment if you plan to have a baby in the future
  • Watery eyes – let your nurse know if you have this
  • Difficulty speaking
  • Nosebleeds

Occasional side effects

Between 1 and 10 in every 100 people have one or more of these.

  • A reaction to bevacizumab during infusion affects around 5 in every 100 people (5%), causing chills, a high temperature (fever) and possibly an itchy rash, feeling sick, breathlessness, wheezing, a headache, flushes and faintness
  • Protein in the urine – your nurse will test your urine regularly. If you have protein in your urine you will need to have a 24 hour urine collection to check your kidneys are working normally
  • Blood clots in a vein – let your doctor or nurse know straight away if you have a sore, red area on your leg or if you have sudden breathlessness and a cough or chest pain
  • Heart problems causing chest pain, swollen ankles, breathlessness and a fast heart rate – tell your doctor or nurse if you have any of these symptoms
  • A split in the wall of the bowel (bowel perforation) affects fewer than 2 in every 100 people treated (2%) but is a serious side effect if it happens
  • Increased risk of bleeding – your gums may bleed easily. The tumour may also bleed. Tell your doctor as soon as possible if you notice any bleeding or if you suddenly feel unwell or have sudden sharp pain
  • An abnormal opening (fistula) between internal organs and the skin or other tissues that are not normally connected
  • Pain the in the abdomen, muscles or joints
  • A dry or sore mouth and feeling thirsty
  • Headaches
  • Blockage in the digestive system (gut)
  • A runny nose
  • Dry, flaky skin or inflamed skin and a change in skin colour
  • A hoarse voice
  • An increased risk of stroke, heart attack or short term loss of blood supply to the brain, caused by blood clotting in an artery – let your doctor or nurse know straight away if you have sudden headaches, dizziness, or faintness

Rare side effects

Fewer than 1 in 100 people have these. If you have any of these symptoms it is important to tell your doctor or nurse.

  • Headaches, seizures (fits), confusion, changes in eye sight, excessive sleepiness, change in behaviour, possibly high blood pressure – doctors call this group of symptoms reversible posterior leucoencephalopathy syndrome (RPLS)
  • Very high blood pressure (hypertensive encephalopathy) – it can occur with other symptoms such as a headache, feeling sick, sleepiness, and confusion
  • Damage to the jawbone and teeth (osteonecrosis) – have a dental check up before you start treatment and tell your dentist that you are having bevacizumab. It is important to clean your teeth regularly. Let your doctor know straight away if you have pain in the mouth, teeth or jaw; swelling or sores inside the mouth; numbness or heaviness of the jaw or loosening of a tooth
  • A serious infection of the skin or deeper layers under the skin

Important points to remember

The side effects above may be mild or more severe. A side effect may get better or worse through your course of treatment, or more side effects may develop as the course goes on. This depends on

  • How many times you've had the drug before
  • Your general health
  • The amount of the drug you have (the dose)
  • Other drugs you are having

Coping with side effects

Talk to your doctor, pharmacist or nurse about all your side effects so they can help you manage them. They can give you advice or reassure you. Your nurse will give you a contact number to ring if you have any questions or problems. If in doubt, call them.

Other medicines

Tell your doctor about any other medicines you are taking, including vitamins, herbal supplements and the counter remedies. Some drugs can react together. Treatments that may react with bevacizumab include

  • Some other cancer drugs – your doctor and pharmacist will check this
  • Radiotherapy
  • Blood thinning drugs – these increase the risk of bleeding

Pregnancy and contraception

This drug may have a harmful effect on a baby developing in the womb. It is important not to become pregnant or father a child if you are having this drug and for 6 months after treatment. Talk about reliable contraception with your doctor or nurse before having the treatment.


Breastfeeding is not advisable during this treatment and for 6 months afterwards because the drug may come through in the breast milk.


Immunisations and bevacizumab

You should not have immunisations with live vaccines while you are having this treatment or for at least 6 months afterwards. In the UK, these include rubella, mumps, measles (usually given together as MMR), BCG, yellow fever and Zostavax (shingles vaccine).

You can have other vaccines, but they may not give you as much protection as usual until your immune system has fully recovered from your treatment. It is safe to have the flu vaccine.

It is safe for you to be in contact with other people who've had live vaccines as injections. There can be problems with vaccines you take by mouth (oral vaccines), but not many people in the UK have these now. So there is usually no problem in being with any baby or child who has recently had any vaccination in the UK. You might need to make sure that you aren't in contact with anyone who has had oral polio, cholera or typhoid vaccination recently, particularly if you live abroad.


More information about bevacizumab

This page does not list all the very rare side effects of this treatment that are very unlikely to affect you. For further information look at the Electronic Medicines Compendium website at

If you have a side effect not mentioned here that you think may be due to this treatment you can report it to the Medicines Health and Regulatory Authority (MHRA) at

Rate this page:
Submit rating


Rated 4 out of 5 based on 28 votes
Rate this page
Rate this page for no comments box
Please enter feedback to continue submitting
Send feedback
Question about cancer? Contact our information nurse team

No Error

Updated: 18 November 2013