Rituximab belongs to a group of targeted therapy drugs called monoclonal antibodies. These drugs are sometimes called targeted (biological) therapies. They work by ‘targeting’ specific proteins (receptors) on the surface of cells.
Monoclonal antibodies target specific proteins (receptors) on the surface of cells. Rituximab targets a protein called CD20. This 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 on some of the abnormal B-cells that occur in CLL.
Rituximab locks on to CD20. It 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.
Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.
You will be given rituximab at a day unit or during a stay in hospital. You may have it on its own or in combination with other cancer drugs.
During treatment you usually see a cancer doctor, a cancer nurse or specialist nurse, and a specialist pharmacist. This is who we mean when we mention doctor, nurse or pharmacist in this information.
Before or on the day of treatment, a nurse or person trained to take blood (phlebotomist) will take a blood sample from you. This is to check that your blood cells are at a safe level to have treatment.
You will see a doctor or nurse before you have treatment. They will ask you how you have been feeling. If your blood results are okay, the pharmacist will prepare your targeted therapy. Your nurse will tell you when your treatment is likely to be ready.
Your nurse will give you drugs before you have rituximab to reduce the chance of a reaction.
You may have rituximab:
- through a short, thin tube the nurse puts into a vein in your arm or hand (cannula)
- through a fine tube that goes under the skin of your chest and into a vein close by (central line)
- through a fine tube that is put into a vein in your arm and goes up into a vein in your chest (PICC line)
- as an injection under the skin (subcutaneous injection).
The nurse will give you rituximab as a drip. This is called an intravenous infusion. The nurse will run the infusion through a pump. This will give you the treatment over a set time.
You may need to stay in hospital overnight for the first treatment so the nurses can check you do not have a reaction to it. After the first treatment, you can usually have rituximab in the outpatient department and over shorter periods of time.
You can only have rituximab as an injection under the skin if you have already had at least 1 treatment as an intravenous infusion. The nurse will give you the injection over 5 minutes.
Your course of treatment
You usually have a course of several cycles of treatment over a few months. Your nurse, pharmacist or doctor will discuss your treatment plan with you.
We explain the most common side effects of this treatment here. We also include some less common side effects.
You may get some of the side effects we mention, but you are unlikely to get all of them. If you are also having treatment with other cancer drugs, you may have some side effects that we have not listed here. Always tell your doctor, nurse or pharmacist about any side effects you have.
Your doctor can give you drugs to help control some side effects. It is important to take them exactly as your nurse or pharmacist explains. This means they will be more likely to work for you. Your nurse will give you advice about managing your side effects. After your treatment is over, most side effects start to improve.
Serious and life-threatening side effects
Some cancer treatments can cause severe side effects. Rarely, these may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.
Contact the hospital
Your nurse will give you telephone numbers for the hospital. If you feel unwell or need advice, you can call them at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.
We cannot list every side effect for this treatment. There are some rare side effects that are not listed. You can visit the electronic Medicines Compendium (eMC) for more detailed information.
Some people may have side effects while they are being given the treatment or shortly after they have it:
Some people have an allergic reaction to rituximab while they are having it. A reaction is most likely to happen with the first infusion, so it is given slowly over a few hours. Before treatment, you will be given medicines to help prevent or reduce any reaction.
Signs of a reaction can include:
- feeling hot or flushed
- a skin rash
- feeling dizzy
- a headache
- feeling breathless or wheezy
- swelling of your face or mouth
- pain in your back, tummy or chest.
Your nurse will check you for signs of a reaction during your infusion. If you feel unwell or have any of these signs, tell them straight away. If you do have a reaction, it can be treated quickly.
Sometimes a reaction happens a few hours after treatment. If you develop any signs or feel unwell after you get home, contact the hospital straight away.
Your blood pressure may fall when you 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. Sometimes, rituximab can make your blood pressure go up. Your nurse will check your blood pressure regularly.
During the infusion, you may have mild pain in the parts of the body where you have cancer. You may be given painkillers to help with this.
Problems at the injection site
If you have rituximab as an injection, you may have some redness and swelling where it is given (injection site). Your nurse can give you advice on coping with this.
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. Sometimes, your treatment may need to be delayed until these levels recover.
Risk of infection
This treatment can reduce the number of white blood cells in your blood. These cells fight infection. If the number of white blood cells is low, you are more likely to get an infection. A low white blood cell count is sometimes called neutropenia.
An infection can be very serious when the number of white blood cells is low. It is important to get any infection treated as soon as possible. Contact the hospital straight away on the 24-hour contact number you have been given if:
- your temperature goes over 37.5°C (99.5°F)
- you suddenly feel unwell, even with a normal temperature
- you have symptoms of an infection
- your temperature goes below 36°C (96.8°F).
Symptoms of an infection include:
- feeling shivery and shaking
- a sore throat
- a cough
- needing to pass urine (pee) a lot, or discomfort when you pass urine.
It is important to follow any specific advice your cancer treatment team gives you.
The number of white blood cells will usually return to normal before your next treatment. You will have a blood test before having more treatment. If your white blood cell count is low, your doctor may delay your treatment for a short time, until your cell count increases.
Anaemia (low number of red blood cells)
This treatment can reduce the number of red blood cells in your blood. Red blood cells carry oxygen around the body. If the number of red blood cells is low, this is called anaemia. You may have symptoms such as:
- pale skin
- lack of energy
- feeling breathless
- feeling dizzy and light-headed.
Tell your doctor or nurse if you have these symptoms.
If you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion.
Bruising and bleeding
This treatment can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot.
If the number of platelets is low, you may bruise or bleed easily. You may have:
- bleeding gums
- heavy periods
- blood in your urine (pee) or stools (poo)
- tiny red or purple spots on the skin that may look like a rash.
Tell your doctor if you have any unexplained bruising or bleeding. You may need a drip to give you extra platelets. This is called a platelet transfusion.
Your doctor will give you anti-sickness drugs to help prevent or control sickness during your treatment. Take the drugs exactly as your nurse or pharmacist tells you. It is easier to prevent sickness than to treat it after it has started.If you feel sick, take small sips of fluids often and eat small amounts regularly. It is important to drink enough fluids. If you continue to feel sick, or are sick (vomit) more than once in 24 hours, contact the hospital as soon as possible. They will give you advice. Your doctor or nurse may change the anti-sickness drug to one that works better for you.
Loss of appetite
This treatment can affect your appetite. Do not worry if you do not eat much for a day or two. But if your appetite does not come back after a few days, tell your nurse or dietitian. They will give you advice. They may give you food or drink supplements.
Raised blood sugar levels
This treatment may raise your blood sugar levels. Symptoms of raised blood sugar include:
- feeling thirsty
- needing to pass urine more often
- 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.
This treatment may affect your skin. It may cause a rash, which might be itchy. You may notice a numbness, tingling, pricking or burning feeling in your skin. Your doctor or nurse can tell you what to expect. If your skin feels dry, try using an unperfumed moisturising cream every day.
Rarely, a much more serious skin condition can develop. You may have a skin rash which then blisters, and your skin can peel. You may also feel unwell with flu-like symptoms such as a high temperature and joint pain. If you have any of these symptoms, contact your doctor or hospital straight away.
Always tell your doctor or nurse about any changes to your skin. They can give you advice and may prescribe creams or medicines to help. Skin changes usually improve after treatment finishes.
Muscle or joint pain
You may get pain in your muscles or joints for a few days after treatment. If this happens, tell your doctor so they can give you painkillers. Tell them if the pain does not get better. If you have painkillers you would like to use at home, check with your doctor, nurse or pharmacist whether they are suitable for you.
If you have muscle or joint pain, try:
- placing a heat pad or covered hot water bottle against the painful area
- taking warm baths
- planning your activities to include regular rests.
This treatment may make your eyes feel sore, red and itchy. This is called conjunctivitis. Your doctor will prescribe eye drops to help. It is important to use these as explained.
Always tell your doctor or nurse if you have eye pain or notice any change in your vision.
Effects on the nervous system
This treatment can affect the nervous system. This can cause symptoms including:
- headaches or dizziness
- problems with eyesight or speech
- confusion, memory loss or drowsiness
- feeling anxious or restless
- having problems sleeping
- seizures (fits)
- weakness in an arm or leg, or in the face muscles
- problems with walking or movement.
Contact the hospital straight away if you have any of these symptoms. If someone with you notices you have any of these symptoms, they should contact the hospital straight away.
It is important not to drive or operate machinery if you have any of these symptoms.
Effects on the lungs
This treatment can cause changes to the lungs. Tell your doctor if you develop:
- a cough
You should also tell them if any existing breathing problems get worse. You may have tests to check your lungs.
Effects on the heart
This treatment can affect how the heart works. You may have tests to see how well your heart is working. These may be done before, during and after treatment.
If the treatment is causing heart problems, your doctor may change the type of treatment you are having.Contact your doctor straight away on the 24-hour number the hospital has given you if you have any of these symptoms during or after treatment:
- pain or tightness in your chest
- changes to your heartbeat.
Other conditions can cause these symptoms, but it is important to get them checked by a doctor. If you cannot get through to your doctor, call the NHS urgent advice number on 111.
Hepatitis B reactivation
Raised levels of uric acid (tumour lysis syndrome)
Rituximab may cause cancer cells to break down very quickly. This releases a waste product called uric acid into the blood. The kidneys usually get rid of uric acid, but they may not be able to cope with large amounts. Too much uric acid can affect the kidneys and the heart. Doctors call this tumour lysis syndrome (TLS). You are more likely to get TLS if you have rituximab with chemotherapy.
Your doctor may give you drugs to help prevent TLS. Drinking at least 2 litres (3½ pints) of fluid each day will also help. You will have regular blood tests to check your uric acid levels.
This treatment may cause hearing changes, including hearing loss. You may have ringing in the ears. This is called tinnitus. You may also become unable to hear some high-pitched sounds. Hearing changes usually get better after this treatment ends. But some can be permanent. Tell your doctor if you notice any changes in your hearing.
Blood clot risk
Cancer and some cancer treatments can increase the risk of a blood clot. Symptoms of a blood clot include:
- throbbing pain, redness or swelling in a leg or arm
- suddenly feeling breathless or coughing
- sharp chest pain, which may be worse when you cough or take a deep breath.
If you have any of these symptoms, contact the hospital straight away on the 24-hour contact number you have been given. If you cannot get through to your doctor, call the NHS urgent advice number on 111.
A blood clot is serious, but it can be treated with drugs that thin the blood (anticoagulants). Your doctor or nurse can give you more information.
You can help reduce the risk of developing a blood clot by:
- staying active during treatment
- drinking plenty of fluids, especially water.
You may be given anticoagulants to help prevent a clot.
Vaccinations can reduce your risk of getting certain infections. Your doctor or nurse may talk to you about having vaccinations.
Doctors usually recommend that people with cancer have a flu vaccination and a coronavirus vaccination. These are both inactivated vaccinations that can help reduce the risk of infection. People with weak immune systems can have these, as they are not live vaccinations.
If your immune system is weak, you need to avoid live vaccinations. This is because they can make you unwell. Live vaccines, such as shingles, contain a very weak version of the illness they are vaccinating you against. Your cancer doctor or GP can tell you more about live and inactivated vaccinations.
Some medicines can affect how this treatment works or be harmful when you are having it. Always tell your cancer doctor about any drugs you are taking or planning to take, such as:
- medicines you have been prescribed
- medicines you buy in a shop or chemist
- vitamins, herbal drugs and complementary therapies.
Tell other doctors, pharmacists or dentists who prescribe or give you medicines that you are having this cancer treatment.
You can visit the electronic Medicines Compendium (eMC) for more detailed information about your treatment.
Your doctor will advise you not to get pregnant or make someone pregnant while having this treatment. The drugs may harm a developing baby. It is important to use contraception during your treatment and for a while after treatment finishes. Your doctor, nurse or pharmacist can tell you more about this.
You are advised not to breastfeed while having this treatment, or for some time after treatment finishes. This is because the drugs could be passed to the baby through breast milk.
Your doctor or nurse can give you more information.
Medical and dental treatment
If you need medical treatment for any reason other than cancer, always tell the doctors and nurses you are having cancer treatment. Give them the contact details for your cancer doctor so they can ask for advice.
If you think you need dental treatment, talk to your cancer doctor or nurse. Always tell your dentist you are having cancer treatment.
This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert health professionals and people living with cancer.
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