How should fostatinib be taken? What is the correct usage and dosage?

Fostamatinib is an oral tyrosine kinase inhibitor mainly used to treat patients with chronic immune thrombocytopenia (ITP), especially for adult patients who have poor response to other first-line treatments (such as glucocorticoids, immunoglobulins). Fostatinib is rapidly metabolized into its active component R406 in the body. It mainly inhibits spleen tyrosine kinase (SYK) to prevent macrophages from destroying platelets, thereby achieving the purpose of increasing the number of platelets.

The recommended starting dose of fostatinib is 100 mg taken orally twice daily. Depending on response to treatment and tolerance, your doctor may increase the dose to 150 mg twice daily after 4 weeks. It should be emphasized that platelet counts must be monitored regularly during medication, and the dosage must be flexibly adjusted based on test results and adverse reactions. If patients experience serious side effects, such as high blood pressure, elevated liver enzymes, or diarrhea, the drug may need to be temporarily discontinued, the dose reduced, or permanently discontinued.

In terms of medication administration, fostatinib should be swallowed whole and can be taken before or after meals, but it is recommended to take the medication at the same time every day to maintain stable blood concentration. If you miss a dose, you should take it as soon as possible. However, if it is close to the time of the next dose, skip the missed dose and do not take a double dose at one time. Patients should avoid taking strong CYP3A4 inhibitors or inducers while taking the drug, as these drugs may affect the metabolism of fostatinib, thereby affecting the efficacy or increasing the risk of toxicity.

In addition, during treatment with fostatinib, patients should regularly undergo liver function, blood pressure, and hematology tests to promptly detect potential adverse reactions, such as ALT/AST elevation, hypertension, increased risk of infection, etc. High blood pressure is a common side effect, and some patients need to take antihypertensive drugs at the same time. In order to obtain better therapeutic effects, patients must strictly abide by medical instructions, take medications on time and cooperate with monitoring to ensure that fostatinib can exert its platelet-raising effect in a safe and controllable manner.

Reference materials:https://go.drugbank.com/drugs/DB12010