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Generic Name: neratinib (ne RA ti nib)
Brand Name: Nerlynx

Medically reviewed by on Sep 25, 2018 – Written by Cerner Multum

What is neratinib?

Neratinib is a cancer medicine that interferes with the growth and spread of cancer cells in the body.

Neratinib is used to treat a certain type of early-stage breast cancer. Neratinib is used for this condition only if your tumor tests positive for a protein called human epidermal growth factor receptor 2 (HER2). HER2 protein can speed the growth of cancer cells.

Neratinib is usually given after you have been treated with another medicine called trastuzumab (Herceptin).

Neratinib may also be used for purposes not listed in this medication guide.

Important Information

Neratinib can cause severe diarrhea, which can be life-threatening if it leads to dehydration. You may be given anti-diarrhea medications for the first 2 months of treatment with neratinib.

Call your doctor if you are sick with severe diarrhea, or you also have weakness, dizziness, or a fever.

Before taking this medicine

You should not use neratinib if you are allergic to it.

Tell your doctor if you have ever had:

You may need to have a negative pregnancy test before starting this treatment.

Neratinib can harm an unborn baby. Use effective birth control to prevent pregnancy while you are using neratinib, whether you are a man or a woman. Neratinib use by either parent may cause birth defects.

If you are a woman, keep using birth control for at least 1 month after your last dose of neratinib. If you are a man, keep using birth control for at least 3 months after your last dose. Tell your doctor right away if a pregnancy occurs while either the mother or the father is using neratinib.

You should not breast-feed while using this medicine and for at least 1 month after your last dose.

How should I take neratinib?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Take the medicine with food, at the same time each day.

The usual dose is 6 tablets taken once daily for 1 year. Follow your doctor's dosing instructions very carefully.

Swallow the tablet whole and do not crush, chew, or break it.

Neratinib can cause severe diarrhea, which can be life-threatening if it leads to dehydration. For the first 2 months of treatment with neratinib, you may need to take medication to prevent or quickly treat diarrhea.

Your doctor may recommend you have an anti-diarrhea medicine such as loperamide (Imodium) available at all times while you are taking neratinib. Take the anti-diarrhea medicine as directed on the label, or as prescribed by your doctor.

To best control diarrhea, you may need to follow a special diet. Get familiar with the list of foods you should eat or avoid to help control diarrhea.

Call your doctor if you are sick with severe diarrhea, or you also have weakness, dizziness, or a fever. You may need to stop taking neratinib for a short time.

You may need frequent blood tests.

Drink plenty of liquids while you are taking neratinib.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include severe diarrhea or vomiting, stomach pain, increased thirst, decreased urination, dark urine, dizziness, or hot and dry skin.

What should I avoid while taking neratinib?

Grapefruit may interact with neratinib and lead to unwanted side effects. Avoid the use of grapefruit products.

If you also take an antacid: Wait at least 3 hours after taking the antacid before you take neratinib.

Neratinib side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • more than 2 bowel movements in 1 day;

  • severe or ongoing diarrhea;

  • pain or burning when you urinate; or

  • liver problems--right-sided upper stomach pain, vomiting, tiredness, fever, itching, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Your cancer treatments may be delayed or permanently discontinued if you have certain side effects.

Common side effects may include:

  • diarrhea;

  • nausea, vomiting, stomach pain, bloating;

  • upset stomach, loss of appetite;

  • feeling tired;

  • rash, dry skin, problems with your fingernails or toenails;

  • dry mouth, mouth sores;

  • muscle spasms; or

  • weight loss.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Neratinib dosing information

Usual Adult Dose for Breast Cancer -- Adjuvant:

240 mg orally once a day continuously for 1 year

Manufacturer suggested prophylactic loperamide dosing:
-Week 1 and 2 (days 1 through 14): 4 mg orally 3 times a day
-Week 3 through 8 (days 15 through 56): 4 mg orally 2 times a day
-Weeks 9 through 52 (days 57 through 365): As needed (not to exceed 16 mg per day)

Use: For the extended adjuvant treatment of adult patients with early stage HER2-overexpressed/amplified breast cancer (to follow adjuvant trastuzumab-based therapy)

What other drugs will affect neratinib?

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Some medicines can make neratinib much less effective when taken at the same time. If you take any of the following medicines, take your neratinib dose 2 hours before or 10 hours after you take the other medicine:

This list is not complete. Other drugs may affect neratinib, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.