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 do not 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 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 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
- 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.
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.
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.
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 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 shivery
- a sore throat
- a cough
- needing to pass urine often.
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 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.
Tell your doctor if you have any bruising or bleeding that you cannot explain. This includes:
- bleeding gums
- tiny red or purple spots on the skin that may look like a rash.
Some people may need a drip to give them extra platelets. This is called a platelet transfusion.
You may feel sick in the first few days after this treatment. 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 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.
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 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. Having warm baths and taking regular rests may help.
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.
Rarely, this treatment can affect the nervous system. It can cause a condition called PML (progressive multifocal leukoencephalopathy). Symptoms include:
- difficulty speaking
- difficulty walking
- memory loss
- changes in your eyesight.
Contact the hospital straight away if you have any of these symptoms. Or if someone with you notices you have these symptoms.
It is important not to drive or operate machinery if you notice these effects.
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 dose 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.
Effects on the lungs
This treatment can cause changes to the lungs. Tell your doctor if you develop:
- a cough
- a fever (high temperature)
You should also tell them if any existing breathing problems get worse. You may have tests to check your lungs.
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.
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 changes that affect the kidneys and the heart. This is called tumour lysis syndrome (TLS). It is more likely if you are having rituximab with chemotherapy.
Your doctor may give you tablets called allopurinol (Zyloric®) to help prevent this. Drinking at least 2 litres (3 ½ pints) of fluid a day will also help. You will have regular blood tests to check the uric acid levels.
Hepatitis B reactivation
Blood clot risk
Cancer and some cancer treatments can increase the risk of a blood clot. Symptoms of a blood clot include:
- pain, redness or swelling in a leg or arm
- chest pain.
If you have any of these symptoms, contact a doctor straight away.
A blood clot is serious, but can be treated with drugs that thin the blood. Your doctor or nurse can give you more information.
Your doctor or nurse may talk to you about vaccinations. These help reduce your risk of getting infections.
Doctors usually recommend that you have a flu jab, which is an inactivated vaccination. People with weak immune systems can have this type of vaccination.
If your immune system is weak, you need to avoid live vaccinations such as shingles. Your cancer doctor or GP can tell you more about live vaccinations.
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.
Your doctor will advise you not to get pregnant or make someone pregnant while having this treatment and for at least a year afterwards. The drugs may harm the developing baby. It is important to use effective contraception.
Women are advised not to breastfeed while having this treatment. This is because the drugs could be passed to the baby through breast milk.
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 cancer treatment.