Formulary
Fostamatinib: Indications, Dosing, Side Effects and Interactions
Fostamatinib, through its metabolite R406, blocks the activity of the spleen tyrosine kinase (SYK) enzyme, thereby reducing immune-mediated destruction of...
MedNext Academy | 3 min read
Fostamatinib: Indications, Dosing, Side Effects and Interactions
Fostamatinib, through its metabolite R406, blocks the activity of the spleen tyrosine kinase (SYK) enzyme, thereby reducing immune-mediated destruction of...
Drug action
Fostamatinib, through its metabolite R406, blocks the activity of the spleen tyrosine kinase (SYK) enzyme, thereby reducing immune-mediated destruction of platelets.
Indications and dose
**Chronic immune thrombocytopenia in patients refractory to other treatments (under expert supervision)**
- **Adult** (By Mouth): Initially 100 mg twice daily; increased if tolerated to 150 mg twice daily after 4 weeks, dose to be adjusted to achieve a platelet count of 50x10 9 /litre or more, discontinue if inadequate response after 12 weeks of treatment, for dose reduction, interruption or treatment discontinuation due to side-effects-consult product literature.
Side effects
Common or very common Chest pain; diarrhoea; dizziness; fatigue; frequent bowel movements; gastrointestinal discomfort; hypertension; increased risk of infection; influenza like illness; nausea; neutropenia; skin reactions; taste altered Frequency not known Hyperbilirubinaemia; hypoxia; nephrolithiasis; pain in extremity; syncope; toothache
Interactions
**Other interactions (3):**
- Fostamatinib Increase in fostamatinib metabolite R406 exposure.
- Co-administration of fostamatinib with Kaletra may increase fostamatinib metabolite R406 exposure resulting in dose-related adverse events such as hepatotoxicity, neutropenia, hypertension, or...
- Refer to the fostamatinib SmPC for dose reduction recommendations if such events occur.
Pregnancy
Manufacturer advises avoid-toxicity in animal studies.
Breast feeding
Manufacturer advises avoid during and for at least 1 month after stopping treatment-metabolites present in milk in animal studies.
Hepatic impairment
Manufacturer advises avoid in severe impairment; caution in mild to moderate impairment-monitor liver function monthly during treatment. Dose adjustments Manufacturer advises consider dose reduction, interruption or treatment discontinuation in mild to moderate impairment-consult product literature.
Medicinal forms
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
Inside MedNext for this topic
- 411 MedNext-authored chapters
- 80,000+ MCQ bank
- 15 study modes
- Growing visual cheat sheets
Study modes
- Notes
- MCQ
- Audio
- Video
- Visual
- 3D Anatomy
- Trace
- Flashcards
- Mnemonics
- Image Bank
- Clinical
- Microscopy
- Audio QBank
- Cadaver
- Book Match
Continue reading
Subject HubPharmacology Hub
All pharmacology resources in one place.
Drug SchedulesIndian Drug Schedules
Schedule H, H1, X and G classifications.
FormularyBrowse all drugs
Search 1,850+ drug profiles.
Study Fostamatinib in the MedNext app
Challenge yourself with targeted pharmacology MCQs on this drug class. Every explanation links back to the chapter that teaches the concept.
Start drug challengeExplore the full formulary

