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Neratinib Side Effects

Medically reviewed by Philip Thornton, DipPharm. Last updated on May 1, 2022.

For the Consumer

Applies to neratinib: oral tablet

Side effects requiring immediate medical attention

Along with its needed effects, neratinib may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking neratinib:

More common

Less common

  • Confusion
  • decreased urination
  • dizziness
  • dry mouth
  • fainting
  • increase in heart rate
  • lightheadedness
  • rapid breathing
  • sunken eyes
  • thirst
  • unusual tiredness or weakness
  • wrinkled skin


  • Bloody urine
  • increased blood pressure
  • increased thirst
  • itching, pain, redness, swelling, tenderness, or warmth on the skin
  • loss of appetite
  • lower back or side pain
  • nausea
  • raised, firm, bright red patches of skin on the arm or leg
  • stomach pain
  • swelling of the face, fingers, or lower legs
  • trouble breathing
  • vomiting
  • weight gain

Side effects not requiring immediate medical attention

Some side effects of neratinib may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • Belching
  • bladder pain
  • bloody nose
  • bloody or cloudy urine
  • decreased appetite
  • decreased weight
  • difficult, burning, or painful urination
  • discoloration of the fingernails or toenails
  • dry skin
  • frequent urge to urinate
  • heartburn
  • indigestion
  • muscle spasms
  • stomach discomfort, upset, or pain
  • swelling or inflammation of the mouth

Less common

  • Deep cracks, grooves, or lines in the skin
  • dry mouth

For Healthcare Professionals

Applies to neratinib: oral tablet


The most common adverse reactions (more than 5%) were diarrhea, nausea, abdominal pain, fatigue, vomiting, rash, stomatitis, decreased appetite, muscle spasms, dyspepsia, increased AST or ALT, nail disorder, dry skin, abdominal distention, decreased weight, and urinary tract infection.[Ref]


Very common (10% or more): Diarrhea (95%), nausea (43%), abdominal pain (36%), vomiting (26%), stomatitis (14%), dyspepsia (10%)

Common (1% to 10%): Abdominal distention, dry mouth[Ref]


Very common (10% or more): Fatigue (27%)[Ref]


Very common (10% or more): Rash (18%)

Common (1% to 10%): Nail disorder, rash, skin fissures[Ref]


Very common (10% or more): Decreased appetite (12%)

Common (1% to 10%): Decreased weight, dehydration[Ref]


Very common (10% or more): Muscle spasms (11%)[Ref]


Common (1% to 10%): Urinary tract infection[Ref]


Common (1% to 10%): Increased ALT, increased AST[Ref]


Common (1% to 10%): Epistaxis[Ref]


Frequency not reported: Hypotension[Ref]


Frequency not reported: Renal failure[Ref]

Frequently asked questions


1. "Product Information. Nerlynx (neratinib)." Puma Biotechnology, Inc. (2017):

Further information

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

Some side effects may not be reported. You may report them to the FDA.