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Neratinib

Neratinib is used to treat breast cancer. Learn how to use the medication, its common side effects, special precautions to watch out for, and more.

What is this medication for?

Neratinib is used to treat HER2-positive breast cancer.

It may be used on its own or together with another medication called Capecitabine.

How should I take or use this medication?

Take Neratinib once a day. Take with food, at around the same time each day.
You may be started on a lower dose for the first few weeks before being given a higher dose.
Swallow the tablet whole. Do not break, chew or crush the tablet.
- Inform your doctor or pharmacist if you have difficulty swallowing.
Do not stop taking your medication without checking with your healthcare professional.

What should I do if I forget to take or use this medication?

If you forget to take a dose, skip the missed dose, and take it at the next scheduled time. Do not take two doses to make up for the missed dose.

What precautions should I take when taking or using this medication?

Inform your healthcare professional if:
- You are allergic to this medication or any of the other ingredients of this medication.
- You are taking any other medications (e.g. for gastric problems), including supplements, traditional medications and herbal remedies.
- You have any other medical conditions such as heart problems or high blood pressure.
You should not breastfeed during treatment and for at least 1 month after stopping Neratinib.
You should not become pregnant while on treatment. You should use an effective birth control method during treatment and for at least 1 month after stopping Neratinib.
If you have a partner who could become pregnant, you should use an effective birth control method during treatment and for at least 3 months after stopping Neratinib.

What are some common side effects of this medication?

The table below will list some of the common side effects as well as the rare but serious side effects.

Side Effect	Management
Diarrhoea (loose and frequent stools)	Drink plenty of clear fluids (at least 2 litres or 8 cups every day). Eat food that is gentler on the stomach such as porridge or soup. Avoid milk, dairy products, high-fibre food and oily or spicy food. Your doctor may prescribe medications to help relieve diarrhoea. Take these as instructed. Proceed to the A&E department if you have very bad diarrhoea (for example increase in bowel movement of more than 4 times per day) that does not improve even after taking anti-diarrheal medications.
Nausea or vomiting This is usually mild.	Take small and frequent meals, rather than 3 large meals. Avoid foods / smells that may make you feel nauseous, such as oily, fried food or strong-smelling food. Avoid tight-fitting clothes around the waist. Your doctor may prescribe medications to help relieve or prevent nausea or vomiting. Take these as instructed.
Abdominal pain	You may experience mild discomfort or pain in the stomach area. Inform your doctor immediately if you experience severe abdominal pain or if there are other symptoms e.g. fever.
Feeling tired or lack of energy	Eat well and get enough sleep. Prioritize tasks to ensure you make the best use of your energy. Do not drive or operate machinery if you are feeling tired. Inform your doctor if your energy level does not improve or gets worse. Simple exercise such as walking can help to boost your energy. Avoid alcohol as this may cause you to feel more tired and drowsy.
Mouth ulcers or sores. This may occur on the tongue, the sides of the mouth or in the throat and can lead to an infection	Rinse your mouth regularly with an alcohol-free mouthwash or salt water to help reduce chances of infection. Brush your teeth gently after eating and at bedtime with a soft bristle toothbrush. Rinse and brush your dentures after eating and soak them in denture cleansing solution overnight. Avoid spicy food and take soft foods e.g. porridge. Your doctor may prescribe medications to help relieve or prevent the mouth sores. Use these as instructed. Inform your doctor if you are eating or drinking a lot lesser because of mouth pain.
Dry skin and rash	You can use moisturiser to prevent dry skin. Inform your doctor if the symptoms become worse.
Poor appetite	Try different flavours of food and small frequent meals.
Liver problems	Proceed to the A&E department immediately if you experience any: Dark or tea-coloured urine Pale or light-coloured stools Yellowing of skin or eyes Nausea, vomiting with loss of appetite Severe stomach pain Keep your doctor informed about any supplements or over-the-counter medications that you take.
Drug Allergy Symptoms may include: Swollen face/eyes/lips/tongue Difficulty in breathing Itchy skin rashes over your whole body	If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately.

It is normal to experience some side effects from Neratinib. As discussed with your doctor, taking Neratinib will be beneficial for your condition. Do not stop taking Neratinib without checking with your doctor.

What food or medication should I avoid when I take or use this medication?

Avoid raw, uncooked, under cooked food.
Inform your healthcare professional if you are taking or intend to take any other medication such as gastric medication e.g. omeprazole, supplements, traditional medications or herbal remedies.
Avoid taking grapefruit when you are taking this medication as grapefruit may interact with it and increase the risk of side-effects.

How should I store this medication?

Store in a cool and dry place at 30 degrees Celsius or below, away from direct sunlight. Keep this medication away from children.

How do I throw away this medication safely?

Pack this medication into a black trash bag and seal it tightly before throwing into the rubbish chute or bin.

What else should I know about this medication?

Tips to help manage your condition while you are on Neratinib

Exercise	Light exercise is recommended as it helps to improve mobility, balance, and even emotional well-being. Avoid strenuous exercise, and rest when you are feeling tired.
Adequate hydration	Maintain adequate hydration with 2 to 3 litres of fluids per day unless you have been informed by your doctor to restrict fluids. This will decrease your chances of getting constipation and prevent dehydration.
Medical and dental treatment	If you need to go to the hospital for any reason other than cancer, always inform the doctors and nurses that you are receiving anti-cancer treatment. Talk to your cancer doctor if you think you need dental treatment. Always inform your dentist that you are receiving anti-cancer treatment.
Seek support if you feel overwhelmed	It is normal to feel fearful or worried about your condition. Do not be afraid to talk about your concerns with your healthcare team or loved ones. There may be resources and support available to help you.

Disclaimer

Please take note that the above is not a complete list of all possible side effects. If you have any concerns about your medication or if you have other side effects that you think are caused by this medication, please consult your doctor or pharmacist.

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last updated on Apr 2025

This article was last reviewed on Friday, April 25, 2025