What is this medicine?

FOSTAMATINIB (fos tam A ti nib) is a medicine that stops your body from destroying platelets. It is used to treat low platelets caused by chronic immune thrombocytopenia (ITP).

This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

COMMON BRAND NAME(S): Tavalisse

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:

  • high blood pressure
  • an unusual or allergic reaction to fostamatinib, other medicines, foods, dyes, or preservatives
  • pregnant or trying to get pregnant
  • breast-feeding

How should I use this medicine?

Take this medicine by mouth with a glass of water. Follow the directions on the prescription label. You can take it with or without food. If it upsets your stomach, take it with food. Take your medicine at regular intervals. Do not take it more often than directed. Do not stop taking except on your doctor's advice.

Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you miss a dose, take the next dose at your regular time. Do not take double or extra doses.

What may interact with this medicine?

This medicine may interact with the following medications:

  • digoxin
  • ketoconazole
  • rifampin
  • rosuvastatin
  • simvastatin
  • verapamil

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medicine?

You may need blood work done while you are taking this medicine.

You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells.

What side effects may I notice from receiving this medicine?

Side effects that you should report to your doctor or health care professional as soon as possible:

  • allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
  • signs and symptoms of infection like fever or chills; cough; sore throat; pain or trouble passing urine
  • signs and symptoms of liver injury like dark yellow or brown urine; general ill feeling or flu-like symptoms; light-colored stools; loss of appetite; nausea; right upper belly pain; unusually weak or tired; yellowing of the eyes or skin

Side effects that usually do not require medical attention (report these to your doctor or health care professional if they continue or are bothersome):

  • abdominal pain
  • diarrhea
  • dizziness
  • nausea
  • tiredness

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medicine?

Keep out of the reach of children.

Store between 20 and 25 degrees C (68 and 77 degrees F). Throw away any unused medicine after the expiration date.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.

Copyright ©2022 Elsevier Inc. All Rights Reserved. Terms of Use.

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy