It is best to read this information with our general information about the type of cancer you have. During treatment, you will see a cancer doctor and a cancer nurse. This is who we mean when we mention doctor or nurse in this information.
Rituximab belongs to a group of cancer drugs known as monoclonal antibodies. These drugs are sometimes called targeted (biological) therapies. They work by ‘targeting’ specific proteins (receptors) on the surface of cells.
Rituximab targets a protein called CD20, which is found on the surface of white blood cells called B-lymphocytes (B-cells). CD20 is found on normal B-cells. It is also found on most of the abnormal (malignant) B-cells that occur in many types of NHL, and some of the abnormal B-cells that occur in CLL.
Rituximab locks on to CD20, and then triggers the body’s immune system to attack the cells and destroy them. Rituximab destroys both abnormal and normal B-cells. Once treatment is over the body can replace the normal B-cells.
The nurse gives you rituximab into a vein with a drip (intravenous infusion). They will usually run the drip through a pump, which will give you the treatment over a set time. If rituximab is used with chemotherapy, it's usually given on the first day of each cycle of chemotherapy treatment.
Sometimes rituximab is given as an injection under the skin (subcutaneous injection). It will only be given this way if you have already had at least one treatment as an intravenous infusion.
You may need to stay in hospital overnight for the first rituximab treatment so the nurses can check to make sure you don’t have a reaction to it. After the first treatment, rituximab can usually be given in the outpatient department and over shorter periods of time.
Possible side effects of rituximabBack to top
We explain the most common side effects of rituximab here. We don’t include all of the less common and rare side effects. You may get some of the side effects we mention, but you will not get them all.
Some side effects may be worse if you’re having chemotherapy with the rituximab. You may also have side effects not listed here. We have more information about chemotherapy.
Your doctor can prescribe drugs to help control some side effects. It is very important to take them exactly as your nurse or pharmacist has explained. This will help the drugs work as well as possible for you.
Your nurse will give you advice about managing side effects. After your treatment is over, side effects will start to improve. Always tell your doctor or nurse about the side effects you have.
Serious and life-threatening side effects
Sometimes cancer drugs can result in very severe allergic reactions. These may be life-threatening, but this is rare. Your cancer doctor and nurse can explain the risk of these side effects to you.
Contact the hospital
Your nurse will give you telephone numbers for the hospital. You can call them if you feel unwell or need advice any time of day or night. Save these numbers in your phone or keep them somewhere safe.
More information about this drug
We’re not able to list every side effect for this treatment here, particularly the rarer ones. For more detailed information you can visit the electronic medicines compendium (eMC).
Side effects during treatment
Some people have an allergic reaction to rituximab. This can happen while it’s being given or for up to two hours afterwards. Allergic reactions are most common with the first few infusions. You will be given drugs before the infusion to reduce the chance of a reaction. A reaction is usually mild. Rarely, it can be more severe. If you have a reaction, the nurses can usually treat this by slowing or stopping the drip. You’ll have the rest of your treatments given at a slower rate.
The nurses will check you for signs of a reaction. But always tell your nurse or doctor if you have any of the following symptoms:
- flu-like symptoms such as a headaches, feeling flushed, having a fever, chills or dizziness
- feeling sick
- a rash or feeling itchy
- breathlessness, wheezing or a cough
- pain in your back, tummy or chest
- feeling unwell.
Rarely, people may have a reaction a few hours after treatment. If you develop any of these symptoms or feel unwell after you get home, contact the hospital straight away for advice.
Some people's blood pressure falls while they are having rituximab. If you usually take medicine to lower your blood pressure, your doctor may ask you not to take it for 12 hours before having rituximab. More rarely, rituximab can make your blood pressure go up. Your nurse will check your blood pressure regularly.
During the infusion, some people have mild pain in the parts of the body where they have cancer. Painkillers can be given to relieve this.
Common side effects of rituximabBack to top
Effect on blood cells
Rituximab can reduce the number of white and red blood cells and platelets in your blood. This is more likely if you are having chemotherapy at the same time. You will have regular blood tests done to check the numbers of blood cells. Occasionally, it may be necessary to delay your treatment until these levels recover.
Risk of infection
If you have a low number of white blood cells you are more likely to get an infection. If this happens during your treatment, your doctor or nurse will advise you how to reduce your risk of infection.
Contact the hospital straight away if:
- your temperature goes over 37.5°C (99.5° F) or over 38°C (100.4° F), depending on the advice given by your healthcare team
- you suddenly feel unwell, even with a normal temperature
- you have symptoms of an infection – this can include feeling shaky, a sore throat, a cough, diarrhoea or needing to pass urine a lot.
Anaemia (low number of red blood cells)
Rituximab can reduce the number of red blood cells in your blood. If the number of red blood cells is low, you may be tired and breathless. Tell your doctor or nurse if you feel like this.
Bruising and bleeding
Rituximab can reduce the production of platelets, which help the blood to clot. Tell your doctor if you have any unexplained bruising or bleeding, such as nosebleeds, bleeding gums, blood spots or rashes on the skin.
This may happen a few hours after treatment and can last for up to a few days. Your doctor can prescribe anti-sickness drugs to prevent or control sickness.
If you still feel sick or are vomiting, contact the hospital as soon as possible. They can give you advice and change the anti-sickness drug to one that works better for you.
Loss of appetite
Some people lose their appetite. This can be mild and may only last a few days. If it doesn’t improve, or you are losing weight, you can ask to see a dietitian or specialist nurse at your hospital. They can give you advice on improving your appetite and keeping to a healthy weight.
Raised blood sugar levels
Rituximab may raise your blood sugar levels. Symptoms of raised blood sugar include feeling thirsty, needing to pass urine more often and feeling tired. Tell your doctor or nurse if you have these symptoms.
If you have diabetes, your blood sugar levels may be higher than usual. Your doctor will talk to you about how to manage this.
Diarrhoea or constipation
You may have diarrhoea, constipation or tummy pain. Your doctor can prescribe drugs to help. Make sure you drink at least two litres (three and a half pints) of fluids every day if you have diarrhoea or constipation.
Rituximab may cause a rash, which can be itchy. You may also notice unusual feelings in your skin such as numbness, tingling, pricking or burning. Rarely, skin reactions can be more severe. Tell your doctor or nurse about any skin changes. They can give you advice and may prescribe creams or medicines to help. Any changes to your skin are usually temporary and improve when treatment finishes.
Muscle and/or joint pain
You may get pain in your joints or muscles. Tell your doctor if this happens so they can prescribe painkillers. Let them know if the pain does not get better. Try to get plenty of rest. Taking regular warm baths may help.
Your eyes may become watery. Your doctor can prescribe eye drops to help with this. Always tell your doctor or nurse if you notice any changes in your vision.
Effects on the nervous system
Rituximab can affect the nervous system. You may feel anxious or restless, have problems sleeping or experience dizziness. Tell your doctor or nurse straight away if you notice any of these symptoms.
It’s important not to drive or operate machinery if you notice these effects.
Effects on the lungs
Rituximab can cause changes to the lungs. Always tell your doctor if you notice wheezing, a cough, fever or feel breathless. You should also let them know if any existing breathing problems get worse. If necessary, they can arrange for you to have tests to check your lungs.
Less common side effects of rituximabBack to top
Changes in the way your heart works
If you already have heart problems, rituximab may make them worse. Your doctor might do tests to see how well your heart is working. Let your doctor know if you have chest pain, difficulty breathing or ankle swelling
Hepatitis B reactivation
If you have had Hepatitis B (a liver infection) in the past, rituximab can make it active again. Your doctor or nurse will talk to you about this and test you for Hepatitis B. If you have active Hepatitis B you will not have treatment with rituximab.
Tumour lysis syndrome (TLS)
Rituximab may cause the cancer cells to break down very quickly. This releases uric acid (a waste product) into the blood. The kidneys usually get rid of uric acid but may not be able cope with large amounts. This can cause chemical imbalances in the blood that affect the kidneys and the heart. Doctors call this tumour lysis syndrome (TLS). It is more likely if rituximab is given with chemotherapy.
To reduce the risk of TLS, your doctor may give you drugs and you may be given fluid through your drip to help protect your kidneys.
Rarely, rituximab may affect your hearing. Tell your doctor if you notice ringing in your ears (tinnitus), or if you have other hearing changes or pain in your ear. These changes will improve when your treatment finishes.
It’s important to let your doctor know straight away if you feel unwell or have any severe side effects, even if they’re not mentioned above.
Other information about rituximabBack to top
You should avoid having live vaccines during treatment and for at least six months afterwards. Live vaccines include BCG (tuberculosis), yellow fever, measles, mumps, rubella, liquid typhoid, poliomyelitis and MMR (combined measles, mumps and rubella).
Some medicines, including those that you can buy in a shop or chemist, can be harmful to take when you are having cancer treatment. Tell your doctor about any medicines you are taking, including over-the-counter drugs, complementary therapies and herbal drugs.
Your doctor will advise you not to become pregnant or to father a child during treatment. This is because the drugs may harm a developing baby. It’s important to use effective contraception during and for 12 months after treatment. You can talk to your doctor or nurse about this.
There is a possible risk that rituximab may be found in breast milk, so women are advised not to breastfeed during this treatment and for at least six months afterwards.
It is not known what effects rituximab may have on your ability to have children in the future. If you have concerns about fertility, it's important to discuss them with your doctor before beginning treatment.
Medical and dental treatment
If you need to go into hospital for any reason other than cancer, always tell the doctors and nurses that you are having rituximab. Give them contact details for your cancer doctor.
Talk to your cancer doctor or nurse if you think you need dental treatment. Always tell your dentist you are having treatment.
This page has been compiled using information from a number of reliable sources, including the electronic Medicines Compendium (eMC; medicines.org.uk). If you’d like further information on the sources we use, please feel free to contact us.
This information was reviewed by a healthcare professional.
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