Irinotecan and cetuximab
This information is about a treatment for advanced bowel cancer
using a combination of a chemotherapy drug and a monoclonal antibody.
You'll see your doctor regularly while you have this treatment so they can monitor the effects of the chemotherapy.
The drugs that are used
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The treatment involves the chemotherapy drug irinotecan, which is also known as Campto®, and the monoclonal antibody cetuximab, which is also known as Erbitux®.
Cetuximab is a type of drug known as a monoclonal antibody. Monoclonal antibodies are used to try to destroy some types of cancer cells while causing little harm to normal cells.
Monoclonal antibodies recognise and lock on to specific proteins on the surface of cancer cells. This helps the body's immune system recognise the cancer cells and destroy them. Monoclonal antibodies are sometimes called targeted therapies because they target cancer cells.
How treatment is given
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This treatment is usually given to you as a day patient. Before you start treatment, you'll need to have a blood test - either on the same day or a few days beforehand. You'll also be seen by a doctor, specialist nurse or pharmacist. If the results of your blood test are normal, the pharmacy will prepare your chemotherapy drugs. This may take a couple of hours.
The nurse will insert a thin, flexible tube (cannula) into a vein in your arm or hand. You may find this uncomfortable or a little painful, but it shouldn't take long. Some people have their chemotherapy given through a thin, plastic tube that's inserted under the skin into a vein near the collarbone (central line), or through a vein in the crook of their arm (PICC line). Your doctor or nurse will explain more about this to you.
Before the chemotherapy you'll be given an anti-sickness (anti-emetic) drug, and some other medicines to help reduce side effects during treatment. These are usually given by injection through the cannula or through your central or PICC line. Some anti-sickness medicines may be given as tablets.
The chemotherapy drugs are then given separately. Both cetuximab and irinotecan are given as a drip (infusion).
If you're having your treatment as a day patient, you can go home after the treatment is finished. The cannula will be removed before you go. If you have a central or PICC line it will usually stay in place, ready for your next cycle of chemotherapy. You will be shown how to look after the line.
Before you go home you'll be given a supply of anti-sickness tablets and anti-diarrhoea medicines to take with you. It's important to take these as directed, even if you aren't feeling sick, as most anti-sickness drugs are much better at preventing sickness than stopping it once it begins.
How often treatment is given
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Your doctor may use the word 'regimen' (eg the irinotecan and cetuximab regimen) when talking about your treatment. This means the whole plan or schedule of your particular treatment.
The cetuximab is given weekly. The first dose is given slowly, usually over two hours. Further weekly treatments are given at a lower dose over about an hour.
After the cetuximab, there will be a gap of at least one hour before having the irinotecan. You may have a saline (salt water) infusion during this time.
The irinotecan is given as an infusion over 30-90 minutes. You will have the irinotecan in one of three ways:
every week for four weeks (followed by two weeks off)
every two weeks
every three weeks.
The dose will vary depending on how often you have it and how well your body copes with the treatment. Your doctor or nurse will explain how often and for how long you will be given the treatment.
Each person’s reaction to chemotherapy is different. Some people have very few side effects, while others may experience more. The side effects described here won't affect everyone who has irinotecan and cetuximab and may be different if you are having more than one chemotherapy drug.
We have outlined the most common side effects but haven't included those that are rare and unlikely to affect you. If you notice any effects that aren't listed here, discuss them with your doctor, chemotherapy nurse or pharmacist.
Cetuximab can occasionally cause an allergic reaction. Signs of this include skin rashes and itching, a feeling of swelling in the tongue or throat, irritation of the nasal passages, wheezing, a cough and breathlessness. You will be monitored closely during your treatment, but tell your nurse or doctor if you have any of these symptoms. To reduce the chance of developing an allergic reaction, medicines (usually antihistamines) or steroids can be given before the infusion. The drip can also be slowed down or stopped until the reaction is over.
Some people having cetuximab may become breathless. This is more likely if you already have lung problems. Let your doctor know if you notice you’re becoming more breathless.
Mild skin rashes are very common with cetuximab. They begin during the first two weeks of treatment and usually go away completely when the treatment stops. Some people have more severe skin changes, which can include reddening of the skin and red pimples and spots on the face. The skin of the face may also become flaky and scaly. Some people have dry skin like eczema on their fingertips, elbows and extremities, which is sore and itchy . If you have any of these skin changes let your doctor know straight away.
If you have very severe skin problems, the length of time between the treatments may be extended or the dose may be lowered. Treatment can be prescribed by your doctor to reduce the rash.
To help reduce dry skin eczema, try to avoid things that make your skin dry, such as central heating and soap. Your doctor, nurse or pharmacist can advise which creams to use to moisturise your skin. They may be bought at a pharmacy or prescribed.
Irinotecan can cause a rash or dry skin, which may be itchy. Your doctor can prescribe medicine to help with this.
Risk of infection
Irinotecan can reduce the number of white blood cells, which help to fight infection. White blood cells are produced by the bone marrow. If the number of your white blood cells is low you will be more prone to infections. A low white blood cell count is called neutropenia.
This effect can begin a few days after treatment and your resistance to infection usually reaches its lowest point around eight days after chemotherapy. The number of white cells in your blood will then increase steadily and usually return to normal before your next cycle of chemotherapy is due.
Contact your doctor or the hospital straight away if:
your temperature goes above 38°C (100.4°F)
you suddenly feel unwell, even with a normal temperature.
You will have a blood test before having more chemotherapy to check the numbers of white cells in your blood. Occasionally it may be necessary to delay your treatment if the number of blood cells (blood count) is still low.
Bruising and bleeding
Irinotecan 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. You can have a platelet transfusion if your platelet count is low.
Irinotecan can reduce the number of red blood cells, which carry oxygen around the body. A low red blood cell count is called anaemia. This may make you feel tired and breathless. Tell your doctor or nurse if you have these symptoms. You may need to have a blood transfusion if the number of red blood cells becomes too low.
Increased sweating, production of saliva, stomach cramps and diarrhoea
Irinotecan can cause increased sweating and production of saliva, stomach cramps and diarrhoea. This is a particular group of side effects known as acute cholinergic syndrome. They happen because irinotecan can cause the cells in the body to release too much of a chemical called acetylcholine. The side effects tend to occur during, or within the first 24 hours after, an infusion of irinotecan.
These symptoms can usually be prevented or controlled by a drug called atropine. Atropine is given as an injection under the skin (subcutaneously), which can be repeated if necessary.
Diarrhoea can occur as a delayed side effect (occurring more than 24 hours after an infusion). It can usually be easily controlled but may occasionally be severe. If you get diarrhoea and abdominal cramps, start taking the anti-diarrhoea medicine that you have been given (usually loperamide tablets or capsules). These should be taken exactly as instructed by the hospital treating you, which may be different from the instructions provided on any printed leaflets from the manufacturer.
Normally your doctor will tell you to take two tablets or capsules when the diarrhoea starts, and then one every two hours until you have not had a loose bowel movement for 12 hours. If loperamide does not work quickly and if you still have diarrhoea after 48 hours, it's important that you contact the hospital. You may become dehydrated if you have several episodes of diarrhoea. In some situations, you may be asked to take liquids to rehydrate yourself and replace any salts you have lost. Antibiotics are also sometimes given if diarrhoea occurs.
Feeling sick (nausea) or being sick (vomiting)
This may begin soon after the treatment is given and can last for up to 24 hours. Your doctor can prescribe very effective anti-sickness (anti-emetic) drugs to prevent or greatly reduce nausea and vomiting. If the sickness isn't controlled, or if it continues, tell your doctor; they can prescribe other anti-sickness drugs which may be more effective.
Some anti-sickness drugs can cause constipation. Let your doctor or nurse know if this is a problem.
Loss of appetite
Some people lose their appetite while they’re having chemotherapy. This can be mild and may only last a few days. If it doesn’t improve 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. You might find our section on eating well useful.
Hair loss usually starts 3-4 weeks after starting treatment, although it may occur earlier. Hair usually falls out completely. You may also have thinning and loss of eyelashes, eyebrows and other body hair. This is temporary and your hair will start to grow again once the treatment has finished. Your hair may grow back straighter, curlier, finer, or a slightly different colour than it was before. Your nurse can give you advice about coping with hair loss.
Feeling tired is a common side effect of chemotherapy especially towards the end of treatment and for some weeks after it’s over. It’s important to try to pace yourself and get as much rest as you need. Try to balance this with some gentle exercise, such as short walks, which will help. If tiredness is making you feel sleepy, don’t drive or operate machinery.
Less common side effects
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Your mouth may become sore or dry, or you may notice small ulcers during this treatment. Drinking plenty of fluids, and cleaning your teeth regularly and gently with a soft toothbrush, can help to reduce the risk of this happening. Some people may find sucking on ice soothing. Tell your nurse or doctor if you have any of these problems, as they can prescribe mouthwashes and medicine to prevent or clear mouth infections. You may find our section on mouth care during chemotherapy helpful.
You may notice that food tastes different. Normal taste usually comes back after treatment finishes. A dietitian or specialist nurse at your hospital can give you advice about ways of coping with this side effect.
Tell your doctor if you have muscle cramps, so that suitable painkillers can be prescribed.
Treatment with irinotecan and cetuximab may cause changes in the way your liver works, although it will return to normal when the treatment finishes. You're very unlikely to notice any problems but your doctor will take regular blood samples to check your liver is working properly.
Fever and chills
These may occur from the time that your treatment is given, but they don’t usually last long. Your doctor may prescribe medicines to reduce these effects.
Cetuximab may cause an inflammation of the lining of the eyelids (conjunctiva) that makes your eyes feel sore, red and itchy. Let your doctor know so they can prescribe soothing eye drops if necessary.
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.
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Risk of developing a blood clot
Cancer can increase the risk of developing a blood clot (thrombosis), and chemotherapy may increase this risk further.
A blood clot may cause symptoms such as pain, redness and swelling in a leg, or breathlessness and chest pain. Blood clots can be very serious so it’s important to tell your doctor straight away if you notice any of these symptoms. Most clots can be treated with drugs that thin the blood. The doctor or nurse can give you more information.
Some medicines, including those that you can buy in a shop or chemist, can be harmful to take when you are having chemotherapy. Tell your doctor about any medicines you are taking, including over-the-counter drugs, complementary therapies and herbal drugs.
Your ability to become pregnant or father a child may be affected by having this treatment. It's important to discuss fertility with your doctor before starting treatment.
It's not advisable to become pregnant or father a child while having irinotecan and cetuximab, as it may harm the developing baby. It’s important to use effective contraception while having this drug, and for at least a few months afterwards. You can discuss this with your doctor.
It’s not known whether chemotherapy drugs can be present in semen or vaginal fluids. To protect your partner it’s safest to either avoid sex or use a barrier form of contraception for about 48 hours after chemotherapy.
There's a risk that chemotherapy drugs may be present in breast milk so women are advised not to breastfeed during chemotherapy and for a few months afterwards.
If you’re admitted to hospital for a reason not related to the cancer, it’s important to tell the doctors and nurses looking after you that you are having chemotherapy treatment. You should tell them the name of your cancer specialist so that they can ask for advice.
It’s a good idea to know who you should contact if you have any problems or troublesome side effects when you’re at home. Your chemotherapy nurse or doctor will give you details of who to contact for advice. This should include ‘out-of hours’ contact details if you need to call someone at evenings, overnight or at the weekend.
This section is based upon our irinotecan and cetuximab fact sheet, which has been compiled using information from a number of reliable sources including:
British National Formulary. 62nd edition. 2011. British Medical Association and Royal Pharmaceutical Society of Great Britain.
D Cunningham, et al. Cetuximab monotherapy and cetuximab plus irinotecan in irinotecan-refractory metastatic colorectal cancer. New England Journal of Medicine. July 2004. 22. 351(4): 337–45.
electronic Medicines Compendium (eMC). www.medicines.org.uk (accessed October 2011).
Perry MC. The Chemotherapy Source Book. 4th edition. 2007. Lippincott Williams and Wilkins.
Sweetman, et al. Martindale. The Complete Drug Reference. 37th edition. 2011. Pharmaceutical Press.