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 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. 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 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.

Rituximab can be given on its own or in combination with other cancer drugs. You will be given rituximab in the chemotherapy day unit or during a stay in hospital. Your doctor will tell you how often you will have this treatment. If rituximab is used with chemotherapy, it is usually given on the first day of each cycle of chemotherapy treatment.

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.

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 start treatment. They will ask you how you have been feeling. If your blood results are okay, the pharmacist will prepare your treatment. Your nurse will tell you when it is likely to be ready.

Your nurse will give you drugs before the rituximab to reduce the chance of a reaction.

Rituximab may be given:

• 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 into a vein as a drip (intravenous infusion). They will run the drip through a pump, which 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 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.

You will only have rituximab as an injection under the skin if you have already had at least one treatment as an intravenous infusion. The nurse will give you the injection over five minutes.

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 haven’t 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.

More information

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 having the rituximab or shortly after they have it.

Allergic reaction

Some people have an allergic reaction to rituximab while they are having it. A reaction is most likely 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
• itching
• shivering
• feeling dizzy
• a headache
• feeling breathless 
• 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 can happen a few hours after treatment. If you develop any signs or feel unwell after you get home, contact the hospital straight away.

Blood pressure

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. Sometimes, rituximab can make your blood pressure go up. Your nurse will check your blood pressure regularly.

Tumour pain

During the infusion, some people have mild pain in the parts of the body where they have cancer. Painkillers can be given 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.

Effects on blood cells

This treatment can reduce the number of blood cells in your blood. You will have regular blood tests to check your blood cell levels. If the number of white blood cells, or blood-clotting cells (platelets), gets too low, your doctor may delay your treatment until the levels improve.

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 called neutropenia.

If you have an infection, it is important to treat it as soon as possible. Contact the hospital straight away on the 24-hour contact number you have 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.

Symptoms of an infection include:

• feeling shaky
• a sore throat
• a cough
• diarrhoea
• needing to pass urine a lot.

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.

Anaemia (low number of red blood cells)

This treatment can reduce the number of red blood cells in your blood. These cells carry oxygen around the body. 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.

If you are very anaemic, you may need a drip to give you extra 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. Tell your doctor or nurse if you have any bruising or bleeding that you can’t explain. This includes:

• nosebleeds
• bleeding gums
• tiny red or purple spots on the skin that may look like a rash.

Feeling sick

Your doctor will give you anti-sickness drugs to help prevent or control sickness. 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 and eat small amounts often. If you continue to feel sick, or if you vomit more than once in 24 hours, contact the hospital as soon as possible. They will give you advice and 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 don’t 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.

Diarrhoea or constipation

You may have diarrhoea or tummy pain. Some people become constipated, but this is less common. Your doctor can give you drugs to help. If you are also having chemotherapy, diarrhoea may be more severe. Follow any instructions the hospital give you. If you have diarrhoea or constipation, make sure you drink at least two litres (three and a half pints) of fluids every day.

Skin changes

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. We have more information about caring for skin and nails.

Muscle and/or joint pain

You may get pain in your joints or muscles. Tell your doctor if this happens so they can give you painkillers. Let them know if the pain does not get better. Having warm baths and taking regular rests may help.

Eye problems

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.

Effects on the nervous system

Rituximab can affect the nervous system. You may feel anxious or restless, have problems sleeping or feel dizzy. Tell your doctor or nurse straight away if you notice any of these symptoms.

It is important not to drive or operate machinery if you notice these effects.

Effects on the lungs

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

• a cough
• wheezing
• a fever (high temperature)
• breathlessness.

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 the way the heart works. You may have tests to see how well your heart is working. These may be done before, during, and sometimes after treatment. If the treatment is causing heart problems, your doctor can change the type of treatment you are having.

Contact a doctor straight away if you:

• have pain or tightness in your chest
• feel breathless or dizzy
• feel your heart is beating too fast or too slowly.

Other conditions can cause these symptoms, but it is important to get them checked by a doctor.

Hepatitis B reactivation

If you have had Hepatitis B (a liver infection) in the past, this treatment can make it active again. Your doctor or nurse will talk to you about this and test you for Hepatitis B.

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 they may not be able to 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.

Your doctor may give you tablets called allopurinol (Zyloric^®) to help prevent this. Drinking at least two litres (three and a half pints) of fluid a day will also help. You will have regular blood tests to check the uric acid levels.

Hearing problems

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 is important to let your doctor know straight away if you feel unwell or have any severe side effects, even if they are not mentioned above.

Vaccines

You should avoid having live vaccines during treatment and for at least six months afterwards. Your doctor can talk to you about vaccines.

Other drugs

Some medicines, including ones you buy in a shop or chemist, can be harmful while you are having this treatment. Tell your cancer doctor about any drugs you are taking, including vitamins, herbal drugs and complementary therapies.

Contraception

Your doctor will advise you not to get pregnant or father a child while having this treatment. The drugs may harm the developing baby. It is important to use effective contraception.

Breastfeeding

Women are advised not to breastfeed while having this treatment and for some time afterwards. This is because the drugs could be passed to the baby through breast milk.

Fertility

Doctors don’t yet know how this treatment may affect your fertility (the ability to become pregnant or father a child). If you are worried about this, talk to you doctor before treatment starts.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the doctors and nurses that 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 this treatment.