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This information is about a chemotherapy| treatment for bowel cancer| called the Mayo regimen.
The Mayo regimen, named after the American hospital that started it, involves the chemotherapy drug fluorouracil| (sometimes known as 5FU) and folinic acid (also known as leucovorin| or LV). Folinic acid is a drug that makes 5FU more effective. Throughout this fact sheet we will refer to fluorouracil by its more common name 5FU.
5FU and folinic acid are commonly used to treat bowel cancer. There are many different ways of giving 5FU and folinic acid together. This fact sheet is specifically about the Mayo regimen.
Mayo treatment can usually be 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|.
All of this may take a couple of hours.
The nurse will then put a thin, flexible tube (cannula) into a vein in your hand or arm. 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 is inserted under the skin and into a vein near the collarbone (central line|), or passed 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. This is usually given by injection through the cannula, central line or PICC line, but may be given as tablets.
The chemotherapy drugs are then given separately:
If you're having your treatment as a day patient you can then usually go home.
You'll be given a supply of anti-sickness drugs to take home with you. It's important to take these as directed even if you aren't feeling sick, as some anti-sickness drugs are much better at preventing sickness than stopping it once it has started.
As you'll be coming back for more treatment over the next four days, your cannula may be left in place and will be securely taped. This means you don't need to have a new cannula each day. The cannula will be removed after the fifth infusion of 5FU and folinic acid. If you have a central or PICC line it will usually stay in place throughout the whole course of your chemotherapy. You'll be shown how to look after the line.
Your doctor may use the word 'regimen|' (eg the Mayo regimen) when talking about your chemotherapy. This refers to the plan or schedule of the particular treatment that you're receiving.
You'll be given 5FU and folinic acid daily for five days. After this you'll have a rest period with no chemotherapy for the next 23 days (just over three weeks). This completes what is called a cycle of the chemotherapy treatment. Each cycle lasts 28 days (four weeks).
You'll start the next cycle of your treatment after the rest period, which will be four weeks after your first injection.
The treatment is usually given for six cycles over a period of six months. This makes up a course of 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 Mayo chemotherapy.
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.
5FU can reduce the number of white blood cells, which help fight infection. White blood cells are produced by the bone marrow|. If the number of your white blood cells is low you'll be more prone to infections|. A low white blood cell count is called neutropenia.
Neutropenia begins seven days after treatment, and your resistance to infection is usually at its lowest 10–14 days after chemotherapy. The number of your white blood cells will then increase steadily and usually return to normal before your next cycle of chemotherapy is due.
You'll have a blood test before having more chemotherapy to check the number of white blood cells. Occasionally, your treatment may need to be delayed if the number of your blood cells (blood count) is still low.
5FU 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 may need to have a platelet transfusion| if your platelet count is low.
5FU 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.
This is usually mild. If you do feel sick, it may begin a few hours after treatment and last for a few days. Your doctor can prescribe 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 that may work better for you. Some anti-sickness drugs can cause constipation. Let your doctor or nurse know if this is a problem.
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.
This is rare with this treatment, but your hair may become thinner. If you lose any hair it will grow back once the treatment has finished. Your nurse can give you advice about coping with hair loss|.
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 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 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.
5FU can cause diarrhoea|. This can usually be easily controlled with medicine, but tell your doctor if it's severe or continues. It's important to drink plenty of fluids if you have diarrhoea.
5FU can cause a rash or dry skin, which may be itchy. Your doctor can prescribe medicine to help with this.
Rarely, your skin may darken. If it does, it usually goes back to normal a few months after the treatment has finished. During treatment and for several months afterwards, you'll be more sensitive to the sun, and your skin may burn more easily than normal. You can still go out in the sun but should wear a suncream with a high sun protection factor (SPF), and cover up with clothing and a hat.
Sometimes areas of skin that have been treated with radiotherapy may become red and sore. Tell your doctor if this happens.
5FU 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.
Your nails may become brittle, chipped and ridged. These changes usually grow out slowly over a few months once the treatment has ended.
5FU may affect the way your heart works. Some people can experience chest pain and tightening across the centre of the chest while taking it. Chest pain can be caused by many different things other than chemotherapy. If you develop any of these symptoms, contact your doctor immediately.
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.
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 you can buy in a shop or chemist, can be harmful to take when you're having chemotherapy. Tell your doctor about any medicines you're 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 5FU 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.
Due to the effect of chemotherapy on the ovaries, women may find that their periods become irregular and may eventually stop. In some women this may be temporary, but for others it will be permanent. This will result in menopausal symptoms|, such as hot flushes, sweats and vaginal dryness.
There's a potential risk that chemotherapy drugs may be present in breast milk. 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're 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 Mayo chemotherapy fact sheet, which has been compiled using information from a number of reliable sources including:
Content last reviewed: 1 December 2011
Next planned review: 2013
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Watch our slideshow with tips for coping with a poor appetite
Watch our slideshow with tips for coping with a sore mouth
Watch our video about coping with fatigue
Watch our slideshow about avoiding infection when you have reduced immunity
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