Drug interactions
Fosamprenavir + Simvastatin
Severity: Contraindicated
Fosamprenavir and Simvastatin: contraindicated interaction.
Last updated Sources: US FDA label
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
Fosamprenavir (converted to amprenavir, often boosted with ritonavir) raises simvastatin concentrations and the risk of rhabdomyolysis. The combination is contraindicated.
What this interaction means in plain words
Fosamprenavir and Simvastatin are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Why it happens
Amprenavir and ritonavir inhibit CYP3A4, reducing the metabolism of simvastatin.
What to do
Do not co-administer; switch to pravastatin or a carefully dosed alternative statin and monitor for muscle toxicity.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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References
Other interactions of Simvastatin
- Atazanavir + Simvastatin Contraindicated
- Clarithromycin + Simvastatin Contraindicated
- Cobicistat + Simvastatin Contraindicated
- Cyclosporin + Simvastatin Contraindicated
- Danazol + Simvastatin Contraindicated
- Darunavir + Simvastatin Contraindicated
Frequently asked questions
Can I take Fosamprenavir with Simvastatin?
MediHelp rates the interaction as contraindicated. Fosamprenavir and Simvastatin are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Fosamprenavir (converted to amprenavir, often boosted with ritonavir) raises simvastatin concentrations and the risk of rhabdomyolysis. The combination is contraindicated.
How serious is the interaction between Fosamprenavir and Simvastatin?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Do not co-administer; switch to pravastatin or a carefully dosed alternative statin and monitor for muscle toxicity.
What other medicines interact with Simvastatin?
MediHelp also lists interactions of Simvastatin with, for example, Atazanavir, Clarithromycin, Cobicistat. The full list is on the Simvastatin page.
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