Drug interactions
Fostamatinib + Lorlatinib
Severity: Moderate
Fostamatinib and Lorlatinib: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Fostamatinib's active metabolite R406 is cleared by CYP3A4, so lorlatinib may lower its exposure and reduce platelet response.
What this interaction means in plain words
Fostamatinib and Lorlatinib can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Fostamatinib belongs to Oncology; Lorlatinib belongs to Oncology.
Why it happens
Lorlatinib induces CYP3A4, increasing R406 metabolism.
What to do
Monitor platelet counts and adjust the fostamatinib dose as clinically needed. Reassess if lorlatinib is stopped.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Lorlatinib
- Amobarbital + Lorlatinib Contraindicated
- Apalutamide + Lorlatinib Contraindicated
- Butabarbital + Lorlatinib Contraindicated
- Carbamazepine + Lorlatinib Contraindicated
- Enzalutamide + Lorlatinib Contraindicated
- Fosphenytoin + Lorlatinib Contraindicated
Other interactions of Fostamatinib
- Colchicine + Fostamatinib Major
- Fostamatinib + Phenytoin Major
- Amobarbital + Fostamatinib Moderate
- Apalutamide + Fostamatinib Moderate
- Atorvastatin + Fostamatinib Moderate
- Bosentan + Fostamatinib Moderate
Frequently asked questions
Can I take Fostamatinib with Lorlatinib?
MediHelp rates the interaction as moderate. Fostamatinib and Lorlatinib can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Fostamatinib's active metabolite R406 is cleared by CYP3A4, so lorlatinib may lower its exposure and reduce platelet response.
How serious is the interaction between Fostamatinib and Lorlatinib?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor platelet counts and adjust the fostamatinib dose as clinically needed. Reassess if lorlatinib is stopped.
What other medicines interact with Lorlatinib?
MediHelp also lists interactions of Lorlatinib with, for example, Amobarbital, Apalutamide, Butabarbital. The full list is on the Lorlatinib page.
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