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Tavalisse Side Effects

Generic Name: fostamatinib

Note: This document contains side effect information about fostamatinib. Some of the dosage forms listed on this page may not apply to the brand name Tavalisse.

For the Consumer

Applies to fostamatinib: oral tablet

What are some side effects that I need to call my doctor about right away?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

  • Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
  • Signs of high blood pressure like very bad headache or dizziness, passing out, or change in eyesight.
  • Signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.
  • Severe diarrhea.
  • Diarrhea that will not go away.
  • Feeling confused.
  • Chest pain.
  • Shortness of breath.
  • Low white blood cell counts have happened with this drug. This may lead to a higher chance of getting an infection. Call your doctor right away if you have signs of infection like fever, chills, or sore throat.

What are some other side effects of this drug?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

  • Diarrhea.
  • Upset stomach.
  • Dizziness.
  • Signs of a common cold.
  • Belly pain.
  • Feeling tired or weak.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at

For Healthcare Professionals

Applies to fostamatinib: oral tablet


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


Very common (10% or more): ALT increased (11%)

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


Very common (10% or more): Respiratory infection (11%)[Ref]


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

Nervous system

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


Very common (10% or more): Hypertension (28%)[Ref]


Common (1% to 10%): Rash (e.g., rash erythematous, rash macular)[Ref]


Very common (10% or more): Diarrhea (31%), nausea (19%)

Common (1% to 10%): Abdominal pain[Ref]


1. "Product Information. Tavalisse (fostamatinib)." Rigel Pharmaceuticals, South San Francisco, CA.

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.

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