How does this medication work? What will it do for me?

Neratinib belongs to the class of medications called antineoplastics (anticancer medications). Specifically, it is a protein-kinase inhibitor. It is taken with hormone-blocking therapy after surgery and within a year of treatment with trastuzumab, to treat early-stage breast cancer that is HER2-receptor positive. It may also be used with capecitabine to treat metastatic breast cancer (cancer that has spread to other parts of the body) that is HER2-receptor positive after trying 2 or more anti-HER2 treatments after metastatic disease was discovered.

This medication works by interfering with the growth of certain cancer cells.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?

Each red, oval-shaped, film-coated tablet, debossed with "W104" on one side and plain on the other side, contains 40 mg of neratinib (as 48.3 mg neratinib maleate). Nonmedicinal ingredients: colloidal silicon dioxide, crospovidone, magnesium stearate, mannitol, microcrystalline cellulose, povidone, and purified water; film coating: iron oxide red, polyethylene glycol, polyvinyl alcohol, talc, and titanium dioxide.

How should I use this medication?

The recommended adult dose of neratinib is 240 mg (six 40 mg tablets) taken by mouth, once daily with food. It should be taken at approximately the same time every day, swallowed whole with a glass of water. Do not chew, crush, or split the tablets before taking them.

To reduce the risk of developing severe diarrhea, your doctor may choose to start with a lower dose and gradually increase it.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor.

If you miss a dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Do not take this medication if you are allergic to neratinib or any ingredients of the medication.

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • acne
  • back pain
  • constipation
  • dizziness
  • dry, inflamed mouth
  • dry skin
  • fatigue
  • flu-like symptoms (sudden lack of energy, fever, cough, sore throat)
  • gas
  • heartburn
  • hemorrhoids
  • joint pain
  • loss of appetite
  • mild diarrhea
  • mouth sores
  • muscle spasms
  • nail problems or breaking
  • nausea
  • nosebleeds
  • rash
  • runny nose
  • upset stomach
  • vomiting
  • weight loss
  • weakness

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • abdominal pain or swelling
  • dehydration (e.g., thirst, headache, loss of appetite, not sweating, decreased urine production, low blood pressure)
  • cough
  • difficulty or painful breathing
  • fever or chills
  • gallstones (e.g., pain in the upper abdomen, pain in the right shoulder, nausea, vomiting)
  • hand-foot syndrome (e.g., pain, tingling, swelling, or redness; calluses and blisters on palms of hands or soles of feet)
  • signs of heart failure (e.g., shortness of breath, fatigue, swelling in legs, ankles, feet)
  • signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
  • signs of pancreatitis (e.g., abdominal pain on the upper left side, back pain, nausea, fever, chills, rapid heartbeat, swollen abdomen)
  • skin inflammation or infection (e.g., pain; tenderness; swelling; painful red, raised patches; fever; chills; feeling unwell)
  • symptoms of kidney problems (e.g., nausea, vomiting, fatigue, changes in urination)
  • symptoms of a urinary tract infection (e.g., pain when urinating, urinating more often than usual, low back or flank pain)
  • uncontrolled diarrhea

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health.

Birth control: Anyone taking neratinib who could become pregnant should use effective birth control (e.g., condoms, birth control pill) during treatment and for at least 1 month after treatment is finished. Those who have partners who could become pregnant should use effective birth control for at least 3 months after the final dose of neratinib.

If you or your partner become pregnant during treatment with this medication, contact your doctor immediately.

Diarrhea: This medication can cause diarrhea that can lead to dehydration. Dehydration can cause many symptoms, including decreased urine production, dry and sticky mouth, sleepiness, dizziness, headache, thirst, and confusion. In some cases, dehydration can become a medical emergency. Your doctor will prescribe another medication to help prevent diarrhea. If you have any questions about how to take this medication, talk to your doctor or pharmacist.

Heart problems: Neratinib may contribute to heart problems, particularly if you have a history of a heart condition, such as congestive heart failure or a past heart attack. If you are at risk of developing heart problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. If you experience symptoms of heart failure, such as increased difficulty breathing, swelling in the feet and ankles, unusual tiredness or a persistent cough, contact your doctor as soon as possible.

Liver problems:  Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Neratinib can cause reduced liver function and can cause liver failure, which may be life-threatening. If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Pregnancy: This medication should not be used during pregnancy. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if neratinib passes into breast milk. If you are breast-feeding and taking this medication, it may affect your baby. People should not breast feed while taking neratinib and for at least 1 month after taking the last dose.

Children: The safety and effectiveness of using this medication have not been established for children.

Seniors: People over the age of 65 are more likely to experience side effects from taking this medication. Depending on how well the medication is tolerated, your doctor may reduce the dose you are taking.

What other drugs could interact with this medication?

For a full list of interactions, use the Drug Interaction Checker available on the website.

If you are taking other medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

All material copyright MediResource Inc. 1996 – 2024. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: