Find out about the side effects of the targeted cancer drug lapatinib.
Tell your doctor or nurse if you have any side effects so they can help you manage them. Your nurse will give you a contact number to ring if you have any questions or problems. If in doubt, call them.
The side effects may be different if you are having lapatinib with other cancer treatments
Common side effects
Each of these effects happens in more than 1 in 10 people (10%). You might have one or more of them.
Tell your doctor or nurse if you have diarrhoea. They can prescribe medicine to help you.
Drink at least 2.5 litres of fluid a day. This helps to keep you hydrated.
Ask your nurse about soothing creams to apply around your back passage (rectum). The skin in that area can get very sore and even break if you have severe diarrhoea.
Diarrhoea can be severe and usually affects more than 3 out of 10 people (30%) taking this drug.
You may notice changes with your skin, such as dryness, itching, rashes and reddening.
Tell your doctor if you have any rashes or itching. Don't go swimming if you have a rash because the chlorine in the water can make it worse.
If your skin gets dry or itchy, smoothing in unperfumed moisturising cream may help. Check with your doctor, pharmacist or nurse before using any creams or lotions. Wear a high factor sun block if you’re going out in the sun.
Skin changes affect about 3 out of 10 people (30%).
You might feel sick or be sick. Anti sickness injections and tablets can control it. Tell your doctor or nurse if you feel sick. You might need to try different anti sickness medicines to find one that works.
- Avoid eating or preparing food when you feel sick.
- Avoid hot fried foods, fatty foods or foods with a strong smell.
- Eat several small meals and snacks each day.
- Relaxation techniques help control sickness for some people.
- Ginger can help – try it as crystallised stem ginger, ginger tea or ginger ale.
- Try fizzy drinks.
- Sip high calorie drinks if you can’t eat.
This can happen in about 1 in 4 people (25%).
You might feel very tired during your treatment. It might take 6 months to a year for your energy levels to get back to normal after the treatment ends. A low red blood cell count will also make you feel tired.
You can do things to help yourself, including some gentle exercise. It’s important not to push yourself too hard. Try to eat a well balanced diet.
Talk to your doctor or nurse if you are finding the tiredness difficult to manage.
Tiredness and weakness (fatigue) affects 1 out of 4 people (25%) during and after treatment.
The skin on your hands and feet may become sore, red, or may peel. You may also have tingling, numbness, pain and dryness. This is called hand-foot syndrome or palmar plantar syndrome. Tell your doctor or nurse if this happens.
- Keep your hands and feet cool.
- Avoid very hot water.
- Don't wear tight fitting gloves or socks.
- Moisturise your skin with non perfumed creams.
- Take vitamin B6 (pyridoxine), which your doctor or nurse can prescribe.
You might lose your appetite for various reasons when you are having cancer treatment. Sickness, taste changes or tiredness can all put you off food and drinks.
- Eating several small meals and snacks throughout the day can be easier to manage.
- Ask your doctor or nurse to recommend high calorie drinks to sip between treatments, if you are worried about losing weight.
- You can make up calories between treatments for the days when you really don’t feel like eating.
- Drink plenty of fluids even if you can't eat.
- Don't fill your stomach with a large amount of liquid before eating.
- Try to eat high calorie foods to keep your weight up.
Contact your doctor or pharmacist if you have indigestion or heartburn. They can prescribe medicines to help.
Let your doctor or nurse know if you have headaches. They can give you painkillers such as paracetamol to help.
Talk to your doctor or nurse if you’re having problems sleeping. It can help to change a few things about when and where you sleep.
- Go to bed and get up at the same time each day.
- Make sure the temperature is right.
- Spend time relaxing before you go to bed - have a bath, read or listen to music.
- Do some light exercise each day to help tire yourself out.
- Avoid caffeine (coffee, tea, chocolate and cola drinks) after early afternoon.
- Have a light snack before you go to bed to stop hunger waking you up.
Let your doctor or nurse know if you have pain anywhere during or after having treatment. There are lots of ways to treat pain, including relaxation and painkillers.
You might have chest pain.
If you have had heart problems you may not be able to have lapatinib.
This is due to a drop in the number of platelets that help clot your blood.
If your platelets get very low you may have lots of tiny red spots or bruises on your arms or legs called petechiae.
Tell your doctor or nurse straight away if you have petechiae.
You have a platelet transfusion if your platelet count is very low. It is a drip of a clear fluid containing platelets. It takes about 15 to 30 minutes. The new platelets start to work right away.
You can get hot flushes. You might also have other symptoms such as:
- reddening of the skin
- a racing heart (palpitations)
- feeling anxious, irritable or panicky
Tips to reduce hot flushes
- Cut out coffee, tea and nicotine.
- Cut down on alcohol.
- Sip cold or iced drinks.
- Wear layers of light clothing so you can take clothes off if you get too hot.
- Have layers of bedclothes to remove as you need to.
- Wear natural fibres such as silk or cotton instead of man made fabrics.
Talk to your doctor if your hot flushes are hard to cope with. They might be able to prescribe medicine.
Tell your doctor or nurse if you’re breathless or have a cough. This could be due to an infection, such as pneumonia. Or it could be caused by changes to the lung tissue, making it less flexible.
Your mouth might get sore. You will have mouth washes to keep your mouth healthy.
You can have painkillers to reduce the soreness. Take them half an hour before meals to make eating easier.
Tell your doctor or nurse if you have this.
Occasional side effects
Each of these effects happens in more than 1 in 100 people (1%). You might have one or more of them.
A small number of people have an allergic reaction, usually during the first or second treatment.
Symptoms include a skin rash, itching, feeling hot and shivering. Other symptoms include redness of the face, dizziness, a headache, shortness of breath and anxiety.
Your nurse will keep a close eye on you and give you treatment straight away if this happens. They might slow your drip down.
Constipation is easier to sort out if you treat it early. Drink plenty of fluids and eat as much fresh fruit and vegetables as you can. Try to take gentle exercise, such as walking.
Tell your doctor or nurse if you are constipated for more than 3 days. They can prescribe a laxative.
Your nails may become brittle, chipped and ridged. Some people have an infection around the nail.
You might have high levels of bilirubin in your blood. You will have regular blood tests to check the bilirubin levels.
More information about this treatment
We haven't listed all the very rare side effects of this treatment. For further information see the electronic Medicines Compendium (eMC) website.
You can report any side effect you have that isn’t listed here to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.