Drug interactions
Ethosuximide + Fosamprenavir
Severity: Moderate
Ethosuximide and Fosamprenavir: 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
Amprenavir, the active form of fosamprenavir, inhibits CYP3A4, and ritonavir boosting increases this effect. Ethosuximide levels may rise and cause dose-related toxicity.
What this interaction means in plain words
Ethosuximide and Fosamprenavir 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.
Why it happens
Inhibition of CYP3A4 reduces ethosuximide clearance.
What to do
Monitor for ethosuximide adverse effects and check serum levels when starting or stopping fosamprenavir. Reduce the ethosuximide dose if needed.
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 Ethosuximide
- Benzhydrocodone / acetaminophen + Ethosuximide Major
- Buprenorphine long-acting + Ethosuximide Major
- Buprenorphine subdermal implant + Ethosuximide Major
- Buprenorphine transdermal + Ethosuximide Major
- Calcium / magnesium / potassium / sodium oxybates + Ethosuximide Major
- Ethosuximide + Fentanyl intranasal Major
Frequently asked questions
Can I take Ethosuximide with Fosamprenavir?
MediHelp rates the interaction as moderate. Ethosuximide and Fosamprenavir 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. Amprenavir, the active form of fosamprenavir, inhibits CYP3A4, and ritonavir boosting increases this effect. Ethosuximide levels may rise and cause dose-related toxicity.
How serious is the interaction between Ethosuximide and Fosamprenavir?
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 for ethosuximide adverse effects and check serum levels when starting or stopping fosamprenavir. Reduce the ethosuximide dose if needed.
What other medicines interact with Ethosuximide?
MediHelp also lists interactions of Ethosuximide with, for example, Benzhydrocodone / acetaminophen, Buprenorphine long-acting, Buprenorphine subdermal implant. The full list is on the Ethosuximide page.
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