Fostamatinib is used to treat chronic immune thrombocytopenia, a bleeding condition caused by a lack of platelets in the blood. fostamatinib is given after other treatments have failed.

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

Fostamatinib can raise your blood pressure, sometimes to dangerous levels. Fostamatinib may also cause liver problems, severe diarrhea, and infections.

Call your doctor if you have: headaches, chest pain, shortness of breath, severe diarrhea, stomach pain, fever, or sore throat.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

You may take fostamatinib with or without food.

Fostamatinib can cause diarrhea. You may need to change your diet, drink extra fluids, or take anti-diarrhea medication. Follow your doctor's instructions for treating or preventing diarrhea.

Fostamatinib can raise your blood pressure, sometimes to dangerous levels. Your blood pressure will need to be checked often.

You will also need frequent medical tests. Your doctor may change your dose, or you may need to stop using fostamatinib based on test results.

Store at room temperature away from moisture and heat. Keep the tablets in their original container, along with the packet or canister of moisture-absorbing preservative.

Usual Adult Dose for Thrombocytopenia:

100 mg orally 2 times a day; after a month, if platelet count has not increased to at least 50 x 10(9)/L, increase to 150 mg orally 2 times a day

Comments:
-This drug may be taken with or without food.
-In the case of a missed dose, instruct patients to take their next dose at its regularly scheduled time.
-Use the lowest dose to achieve and maintain a platelet count at least 50 x 10(9)/L to reduce the risk of bleeding.

Use: For the treatment of thrombocytopenia in adult patients with chronic immune thrombocytopenia (ITP) who have had an insufficient response to a previous treatment

Fostamatinib is not approved for use by anyone younger than 18 years old.

Tell your doctor if you have ever had:

• high blood pressure; or

• liver problems.

Do not use fostamatinib if you are pregnant. It could harm the unborn baby. Use effective birth control to prevent pregnancy while you are using fostamatinib and for at least 1 month after your last dose.

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

Skip the missed dose and use your next dose at the regular time. Do not use two doses at one time.

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

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Do not remove the desiccant canisters (a small canister that contains a substance that absorbs moisture to keep the medication dry).

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

Unless your doctor tells you otherwise, continue your normal diet.

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

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

Fostamatinib may cause serious side effects. Call your doctor at once if you have:

• severe diarrhea;

• stomach pain (upper right side);

• dark urine, jaundice (yellowing of the skin or eyes);

• headaches, chest pain, shortness of breath; or

• fever, sore throat, or other signs of infection.

Your fostamatinib doses may be delayed or permanently discontinued if you have certain side effects.

Common side effects of fostamatinib may include:

• increased blood pressure;

• diarrhea, nausea, stomach pain;

• abnormal liver function tests;

• chest pain;

• dizziness, tiredness;

• rash; or

• cold symptoms such as stuffy nose, sneezing, sore throat.

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.

Other drugs may affect fostamatinib, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests to check your body's response to fostamatinib. Your doctor will also check your blood pressure regularly during your treatment with fostamatinib.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.