Product Code: PR90123993
What Is This Drug?
TAVALISSE is an oral tablet for treating the autoimmune disease, chronic immune thrombocytopenia (ITP), in adults who were unresponsive to other therapies. [1,2] Thrombocytopenia is a condition in which the platelet (a type of blood cell) count is less than normal whereas chronic ITP is a condition that causes unusual bleeding due to lower platelet count.  In ITP, our immune system causes antibody production that destroys the platelets in the body.  Fostamatinib, the active ingredient of TAVALISSE,  inhibits the process of platelet destruction, causing a rise in the platelet count. 
Classification and Mechanism of Action
Fostamatinib is a small molecule spleen tyrosine kinase (Syk) inhibitor with possible immunomodulating and anti‑inflammatory activities.  In ITP, the FcƳ receptors in our immune system transmit a signal that produces antibodies that destroy the platelets in the body.
R406, the active metabolite of fostamatinib, inhibits the spleen enzyme Syk, which is involved in the signal transmission by the FcƳ receptor. The inhibition of Syk thus inhibits the destruction of platelets and brings about an increase in platelet count.  Fostamatinib is used in treating chronic ITP in adults who have had insufficient response to other therapies. 
Looking After Your Drug
Store in a cool place. Protect from moisture, direct sunlight, and heat. Do not freeze. Keep it away from children. Store it at 20°C to 25°C; variations permitted from 15°C to 30°C. 
Dosage Form And Strength
Fostamatinib is available in a tablet form in two strengths, 100 mg and 150 mg. 
Fostamatinib therapy should be initiated with a 100 mg tablet taken by mouth two times a day, with or without food. The dose may be increased to 150 mg if the 100 mg tablet is unable to raise the platelet count to 50 x 109/L. Take the fostamatinib tablet as directed by the physician. Do not take a lower or higher dose than that prescribed by the physician. In case you miss a dose, ensure that you receive the next dose at its regular scheduled time. 
How to Take the Medication?
This drug should only be consumed if prescribed by a registered medical practitioner. Fostamatinib should be taken with water, before or after meals. It should not be used in individuals below 18 years of age. 
Seek medical help in case of an overdose and contact the Poison Control Centre. No specific antidote is available for fostamatinib overdose. R406, which is the active product of fostamatinib metabolism, has negligible clearance through dialysis. The exact treatment for overdose depends on the clinical status of the patient which creates a need for monitoring the individual for various symptoms of overdose. The adverse reaction to fostamatinib overdose can be treated with supportive care. [1,2] If the individual has collapsed, cannot breathe, fainted, is experiencing a seizure due to overdose, contact the Poison Control Centre immediately. 
Warnings and Precautions
Fostamatinib is avoided in pregnant women as it may harm the fetus severely. It is also to be avoided in breastfeeding mothers as no data about it is available. A lactating mother should not breastfeed for at least a month after the dose of fostamatinib. It must be avoided in individuals below 18 years of age as no data is available on the safety and efficacy of fostamatinib in that age group. Don’t use any other medication with fostamatinib without consulting your doctor as it may affect the efficacy of the drug and cause an adverse reaction. It should be used with caution in people with the following ailments: 
- Hypertension: Weekly evaluation of blood pressure can help prevent a hypertensive crisis.
- Hepatotoxicity: Regular evaluation of liver enzymes is needed and any changes in the levels should be managed appropriately by the doctor.
- Diarrhea: Supportive measures may be needed to manage diarrhea. If it becomes difficult to manage, the dose is interrupted, reduced, or the drug therapy is discontinued.
- Neutropenia: Neutropenia is a reduction in the white blood cell count. A regular blood checkup is recommended to individuals on fostamatinib therapy. If the neutrophil count is reduced, your doctor may reduce the dose or discontinue the therapy depending upon your condition.
Possible Side Effects
Fostamatinib is an oral therapy for the treatment of chronic ITP in adult individuals. Before using fostamatinib, individuals should consult a physician.  Some of the common side effects of fostamatinib are: 
Consult a physician if any of the side effects of fostamatinib are observed. Fostamatinib can cause other severe side effects such as: 
- Severe diarrhea
- Nausea and vomiting
- Dark colored urine
- Headache, dizziness, and confusion
- Difficulty breathing
- Yellowing of the eyes or skin
When the Drug Should Not Be Used?
Before the treatment, the medical history of the patient should be studied thoroughly. The doctor must be informed about hypertension, liver disease, current or future pregnancy plans, and breastfeeding. Before beginning the therapy, the doctor must also be informed about any prescription or over-the-counter medicines taken by the patient, including the herbal and vitamin supplements. 
- Highlights of prescribing information [Internet] [Updated Apr 2018]. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/209299lbl.pdf. Accessed on Oct 16, 2018.