Rituximab

Rituximab is used to treat non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukaemia (CLL). It is best to read this information with our general information about the type of cancer you have.

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.

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.

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.

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.

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.

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
• breathlessness
• diarrhoea
• 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.

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.

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:

• nosebleeds
• 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.

This treatment can affect your appetite. Don't worry if you do not eat much for a day or 2. But if your appetite does not come back after a few days, or if you are losing weight, tell your nurse or dietitian. They can give you advice. They may give you food or drink supplements. Or they may suggest changes to your diet or eating habits to help.

Rituximab may raise your blood sugar levels. If you have raised blood sugar, you may:

• feel thirsty
• need to pee more often
• feel 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. You may need to change your insulin or tablet dose.

You may have diarrhoea, constipation or tummy pain. Tell your doctor if you have any of these. They can prescribe drugs to help. Make sure you drink at least 2 litres (31/2 pints) of fluids every day if you have diarrhoea or constipation.

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.

Your hair may get thinner. Or you may lose all the hair from your head. You may also lose your eyelashes and eyebrows, as well as other body hair.

Your nurse can talk to you about ways to cope with hair loss.

Hair loss is almost always temporary. Your hair will usually grow back after treatment finishes.

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 (conjunctivitis). Your doctor will prescribe eye drops to help. It is important to use these as instructed.

Always tell your doctor or nurse if you have pain or notice any change in your vision.

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.

This treatment can cause changes to the lungs. Tell your doctor if you develop:

• a cough
• wheezing
• breathlessness.

You should also tell them if any existing breathing problems get worse. You may have tests to check your lungs.

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 (covid) 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 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.

Some cancer drugs can affect whether you can get pregnant or make someone pregnant. If you are worried about this, it is important to talk with your doctor before you start 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.