Cancer drugs A to Z list
Lonsurf is a treatment for:
bowel cancer that has spread to other parts of the body
stomach (gastric) cancer that has spread to other parts of the body
of the that has spread to another part of the body
Find out more about your cancer type
Lonsurf is made up of 2 drugs, trifluridine and tipiracil.
Trifluridine works by stopping the growth of cancer cells. Tipiracil helps the trifluridine to work longer by stopping it from being broken down by the body.
You take Lonsurf as tablets. Your doctor will tell you how many tablets to take. You take them twice a day with a glass of water. You need to take them within an hour after your morning and evening meals.
You must take tablets according to the instructions your doctor or pharmacist gives you.
Speak to your pharmacist if you have problems swallowing the tablets.
Whether you have a full or an empty stomach can affect how much of a drug gets into your bloodstream.
You should take the right dose, no more or less.
Talk to your healthcare team before you stop taking or miss a dose of a cancer drug.
You take Lonsurf in a 4 week as shown below.
Days 1 to 5 – take the tablets twice a day
Days 6 to 7 – don’t take the tablets
Days 8 to 12 – take the tablets twice a day
Days 13 to 14 – don’t take the tablets
Don’t take any of the tablets
Then you start the cycle again.
You usually take Lonsurf for as long as it helps you and the side effects aren't too bad.
You have blood tests before and during your treatment. They check your levels of blood cells and other substances in the blood. They also check how well your liver and kidneys are working.
Side effects can vary from person to person. They also depend on what other treatments you're having.
Your doctor, nurse or pharmacist will go through the possible side effects. They will monitor you during treatment and check how you are at your appointments. Contact your advice line as soon as possible if:
you have severe side effects
your side effects aren’t getting any better
your side effects are getting worse
Early treatment can help manage side effects better.
We haven't listed all the side effects here. Talk to your healthcare team if you have any new symptoms that you think might be a side effect of your treatment.
Remember it is very unlikely that you will have all of these side effects. But you might have some of them at the same time.
These side effects happen in more than 10 in 100 people (more than 10%). You might have one or more of them. They include:
Increased risk of getting an infection is due to a drop in white blood cells. Symptoms include a change in temperature, aching muscles, cough, headaches, feeling cold and shivery, pain or a burning feeling when peeing, or generally feeling unwell. You might have other symptoms depending on where the infection is.
Infections can sometimes be life threatening. You should contact your advice line urgently if you think you have an infection.
This is due to a drop in the number of platelets in your blood. These blood cells help the blood to clot when we cut ourselves. You may have nosebleeds or bleeding gums after brushing your teeth. Or you may have lots of tiny red spots or bruises on your arms or legs. This is known as petechiae.
You might be breathless and look pale due to a drop in red blood cells. This is called anaemia.
You might not feel like eating and may lose weight. Eating several small meals and snacks throughout the day can be easier to manage. You can talk to a dietitian if you are concerned about your appetite or weight loss.
You might feel very tired and as though you lack energy.
Various things can help you to reduce tiredness and cope with it, for example exercise. Some research has shown that taking gentle exercise can give you more energy. It is important to balance exercise with resting.
Feeling or being sick is usually well controlled with anti sickness medicines. It might help to avoid fatty or fried foods, eat small meals and snacks and take regular sips of water. Relaxation techniques might also help.
It is important to take anti sickness medicines as prescribed even if you don’t feel sick. It is easier to prevent sickness rather than treat it once it has started.
Contact your advice line if you have diarrhoea. For example, in one day you have 2 or more loose bowel movements than usual. If you have a , you might have more output than normal. Your doctor may give you anti diarrhoea medicine to take home with you after treatment.
Try to eat small meals and snacks regularly. It’s best to try to have a healthy balanced diet if you can. You don’t necessarily need to stop eating foods that contain fibre. But if your diet is normally very high in fibre, it might help to cut back on high fibre foods such as beans, nuts, seeds, dried fruit, bran and raw vegetables.
Drink plenty to try and replace the fluid lost. Aim for 8 to 10 glasses per day.
These side effects happen in between 1 and 10 out of every 100 people (between 1 and 10%). You might have one or more of them. They include:
weight loss
constipation – drink plenty and eat foods high in fibre. Your nurse can give you laxatives to help if needed
changes to your taste
feeling dizzy
a headache
feeling generally unwell (malaise)
liver changes picked up on blood tests
redness, swelling and pain on the palms of hands or soles of feet
numbness or tingling, usually in your fingers or toes
sore mouth or ulcers
protein in your urine – your nurse tests your urine before and during treatment
problems with staying or falling asleep (insomnia)
cough or shortness of breath – tell your doctor if you have any shortness of breath
skin problems such as a rash, itchy or flaky skin or flushing – talk to your team about any changes to your skin
tummy pain
low levels of albumin in your body that can cause swelling and weakness
hair loss – this is usually temporary and grows back after treatment finishes
These side effects happen in fewer than 1 in 100 people (less than 1%). You might have one or more of them. They include:
a blood clot – this can be life threatening. Signs are pain, redness and swelling where the clot is. Feeling breathless or pain in your chest or upper back can be a sign of a blood clot in the lung. Contact your advice line or go to A&E straight away
septic shock – this is a life threatening condition it happens after a serious infection. Signs include low blood pressure, high fever, chills, confusion, general pain, fast heartbeat, rapid breathing and a rash. Contact the advice line or see your doctor
ear ache
indigestion
changes in blood pressure – it may be higher or lower than normal
eye problems such as changes to your sight, or red, sticky eyes that feel gritty and may water (conjunctivitis) or dry eyes – call your advice line about any eye problems
pain, including in your muscles, joints, bones or tumour
anxiety
changes to your periods (menstrual cycle)
changes to the levels of minerals and salts in your body – picked up on blood tests
kidney problems including kidney failure
passing out or fainting
high blood sugar levels
problems passing urine or loss of bladder control
changes in heart rhythm
We have more information about side effects and tips on how to cope with them.
Read more about how to cope with side effects
Cancer drugs can interact with medicines, herbal products, and some food and drinks. We are unable to list all the possible interactions that may happen. An example is grapefruit or grapefruit juice which can increase the side effects of certain drugs.
Tell your healthcare team about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies. Also let them know about any other medical conditions or allergies you may have.
It is not known whether this treatment affects in people. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.
This treatment might harm a baby developing in the womb. It is important not to become pregnant or father a child while you are having treatment and for 6 months afterwards. Talk to your doctor or nurse about effective contraception before starting treatment.
Don’t breastfeed during this treatment because the drug may come through into your breast milk.
Don’t have immunisations with live vaccines while you’re having treatment and for up to 12 months afterwards. The length of time depends on the treatment you are having.
Ask your doctor or pharmacist how long you should avoid live vaccinations.
In the UK, live vaccines include rubella, mumps, measles, BCG, and yellow fever.
You can usually have:
other vaccines, but they might not give you as much protection as usual
the flu vaccine (as an injection)
the coronavirus (COVID-19) vaccine
Talk to your doctor or pharmacist about the best time to have a vaccine in relation to your cancer treatment.
You can be in contact with other people who have had live vaccines as injections. If someone has had a live vaccine by mouth or nasal spray there may be a small risk the vaccine virus can be passed onto you if your is weakened.
Your healthcare team will let you know if you need to take any precautions if you are in close contact with someone who has had a live vaccine.
Read more about immunisations and cancer treatment
If you are having tests or treatment for anything else, always mention your cancer treatment. For example, if you are visiting your dentist.
For further information about this treatment and possible side effects go to the electronic Medicines Compendium (eMC) website. You can find the patient information leaflet on this website.
You can report any side effect you have to the Medicines and Healthcare products Regulatory Agency (MHRA) as part of their Yellow Card Scheme.
Last reviewed: 18 May 2023
Next review due: 18 May 2026
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