Bevacizumab (Avastin®)
This information is about bevacizumab (pronounced be-vac-i-zoo-mab) which is commonly known as Avastin®. It is used to treat people with cancer of the large bowel (colon and rectum). Avastin may also be used to treat other types of cancer as part of a research trial.
- What is Avastin?
- Monoclonal antibodies
- How Avastin works
- What it looks like
- How it is given
- Possible side effects
- Less common side effects
- Additional information
What is Avastin?
Avastin is one of a new group of cancer drugs known as monoclonal antibodies. In the UK it is currently given along with chemotherapy, usually 5FU (fluorouracil) and leucovorin, and sometimes with irinotecan as well. It is given to people who have advanced bowel cancer (cancer that has spread to other parts of the body).
Monoclonal antibodies
Monoclonal antibodies can destroy some types of cancer cells while causing little harm to normal cells. They do this by recognising certain proteins that are found on the surface of some types of cancer cells (known as receptors) and 'locking' themselves onto them.
There are different types of antibodies that work in different ways. Once the monoclonal antibody has attached to the receptor it can:
- trigger the body’s immune system to attack the cancer cells and cause the cells to destroy themselves, or
- block the receptor from connecting with a different protein that helps the cell to grow, which may stop the cells from growing and dividing, or prevent the cancer cells from developing a new blood supply.
How Avastin works
Avastin can stop some cancers from developing new blood vessels. This reduces the cancer’s supply of oxygen and nutrients, which causes the tumour to shrink, or at least to stop growing. Drugs that interfere with blood vessel growth in this way are called angiogenesis inhibitors or anti-angiogenics.
How it is given
Avastin is given through a small tube (cannula) inserted into a vein. It may be given in combination with chemotherapy drugs, usually irinotecan, fluorouracil (5FU) and leucovorin (folinic acid).
Some people have their Avastin and chemotherapy given through a fine plastic tube which is inserted under the skin into a vein near the collarbone (central line), or passed through a vein in their arm (PICC line). Your doctor or nurse will explain more about this to you.
Possible side effects
Each person’s reaction to cancer treatment is different. Some people have very few side effects, while others may experience more. The side effects described in this information will not affect everyone who is given Avastin. The drug is often used in combination with chemotherapy, so patients will also have side effects from the chemotherapy. The side effects mentioned below are those caused by Avastin.
We have outlined the most common side effects, but have not included those that are very rare and therefore extremely unlikely to affect you. If you notice any effects that you think may be due to the drug, but which are not listed below, please discuss them with your doctor or nurse.
High blood pressure Your blood pressure will be checked regularly. If you have any headaches, nosebleeds or feelings of dizziness let your doctor know.
Allergic reactions It is common to have a slight allergic reaction to Avastin, although some people have a more severe reaction. Signs of a reaction include skin rashes and itching, a feeling of swelling in the tongue or throat, irritation of the nasal passages, wheezing, a cough and breathlessness. You will be monitored closely during your treatment but it is very important to tell your nurse or doctor if you have any of these symptoms.
Slow wound healing Wounds may take longer to heal while you are having treatment with Avastin.
Constipation Let your doctor know if you develop constipation. This can often be relieved with a high-fibre diet or laxatives.
Circulatory problems There have been some reports of an increased risk of blood clots (DVT), stroke and angina (heart pain) in people taking Avastin.
Changes in the way your heart works Symptoms of this will include chest pain, difficulty breathing, and swelling of the ankles (water retention). Let your doctor know if you develop any of these symptoms.
Lowered resistance to infection Avastin can reduce the production of white blood cells by the bone marrow, making you more prone to infection. Contact your doctor or the hospital straightaway if:
- Your temperature goes above 38ºC (100.5ºF)
- You suddenly feel unwell (even with a normal temperature).
You will have a blood tests during your treatment to make sure that your blood cells have recovered. Occasionally it may be necessary to delay your treatment if your blood count is still low.
Bruising or bleeding Avastin can reduce the production of platelets (which help the blood to clot). Let your doctor know if you have any unexplained bruising or bleeding, such as nosebleeds, blood spots or rashes on the skin, and bleeding gums.
Damage to the kidneys Avastin can sometimes temporarily change the way that your kidneys work. You may have blood tests to check that your kidneys are working well.
Less common side effects
Diarrhoea This can usually be easily controlled with medicine, but let your doctor know if it is severe or if it continues. It is important to drink plenty of fluids if you have diarrhoea.
Tiredness and a general feeling of weakness You may feel very tired. It is important to allow yourself plenty of time to rest.
Nausea and vomiting If this happens it may begin a few hours after the treatment is given and last for up to a few days. Your doctor can now prescribe very effective anti-sickness (anti-emetic) drugs to prevent or greatly reduce nausea and vomiting. If the sickness is not controlled, or if it continues, tell your doctor, who can prescribe other anti-sickness drugs which may be more effective.
Headaches Let your doctor know if you have headaches while you are having Avastin treatment.
Sore mouth and taste change Your mouth may become sore, or you may notice small ulcers during this treatment. Drinking plenty of fluids and cleaning your teeth regularly and gently with a soft toothbrush can help reduce the risk of this happening. Tell your nurse or doctor if you have any of these problems, as they can give you special mouthwashes and medicine to prevent or clear any mouth infection.
Loss of appetite You may find that you do not feel like eating. A dietitian or specialist nurse at the hospital can give advice on boosting your appetite and eating well.
Pain in the area of the tumour Some people may have pain in the area of the tumour.
If you have any questions about these or any other side effects talk to your doctor or nurse. It is important to let them know if you have any symptoms or side effects that may be related to any treatment you are having.
Additional information
Some other medicines can be harmful to take when you are having Avastin. Let your doctor know about any medications you are taking, including non-prescribed drugs such as complementary therapies and herbal drugs.
In some people with lung cancer there is a risk of bleeding into the lung tissue. If people have already coughed up blood they should not have treatment with Avastin.
Contraception It is not advisable to become pregnant or father a child while taking Avastin as not enough is known about its effect on the developing foetus. It is important to use effective contraception during your treatment and for a year afterwards. You can discuss this with your doctor or specialist nurse.
