Drug interactions
Fostemsavir + Valsartan
Severity: Moderate
Fostemsavir and Valsartan: 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
Fostemsavir's metabolite inhibits OATP1B1/1B3, which transport valsartan into hepatocytes, so valsartan exposure may increase. The expected effect is a stronger hypotensive response and a higher potential for adverse effects.
What this interaction means in plain words
Fostemsavir and Valsartan 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.
Fostemsavir belongs to Anti Virals; Valsartan belongs to Cardiovascular.
Why it happens
Inhibition of OATP1B1/1B3-mediated hepatic uptake of valsartan by fostemsavir.
What to do
Monitor blood pressure and renal function and lower the valsartan dose if hypotension occurs.
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 Valsartan
- Aliskiren + Valsartan Contraindicated
- Sparsentan + Valsartan Contraindicated
- Aldesleukin + Valsartan Major
- Amifostine + Valsartan Major
- Amiloride + Valsartan Major
- Amlodipine-benazepril + Valsartan Major
Other interactions of Fostemsavir
- Apalutamide + Fostemsavir Contraindicated
- Carbamazepine + Fostemsavir Contraindicated
- Enzalutamide + Fostemsavir Contraindicated
- Fostemsavir + Mitotane Contraindicated
- Fostemsavir + Phenytoin Contraindicated
- Fostemsavir + Rifampicin Contraindicated
Frequently asked questions
Can I take Fostemsavir with Valsartan?
MediHelp rates the interaction as moderate. Fostemsavir and Valsartan 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. Fostemsavir's metabolite inhibits OATP1B1/1B3, which transport valsartan into hepatocytes, so valsartan exposure may increase. The expected effect is a stronger hypotensive response and a higher potential for adverse effects.
How serious is the interaction between Fostemsavir and Valsartan?
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 blood pressure and renal function and lower the valsartan dose if hypotension occurs.
What other medicines interact with Valsartan?
MediHelp also lists interactions of Valsartan with, for example, Aliskiren, Sparsentan, Aldesleukin. The full list is on the Valsartan page.
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