Drug interactions
Ethosuximide + Ritonavir
Severity: Moderate
Ethosuximide and Ritonavir: 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
Ritonavir is a potent CYP3A4 inhibitor and may increase ethosuximide concentrations. Toxicity such as sedation, ataxia and gastrointestinal effects may result.
What this interaction means in plain words
Ethosuximide and Ritonavir 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.
Ethosuximide belongs to Central Nervous System; Ritonavir belongs to Anti Virals.
Why it happens
Potent CYP3A4 inhibition by ritonavir reducing ethosuximide metabolism.
What to do
Monitor for ethosuximide toxicity and serum levels, and reduce the dose as 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
Other interactions of Ritonavir
- Alfuzosin + Ritonavir Contraindicated
- Amiodarone + Ritonavir Contraindicated
- Avanafil + Ritonavir Contraindicated
- Colchicine + Ritonavir Contraindicated
- Dronedarone + Ritonavir Contraindicated
- Eletriptan + Ritonavir Contraindicated
Frequently asked questions
Can I take Ethosuximide with Ritonavir?
MediHelp rates the interaction as moderate. Ethosuximide and Ritonavir 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. Ritonavir is a potent CYP3A4 inhibitor and may increase ethosuximide concentrations. Toxicity such as sedation, ataxia and gastrointestinal effects may result.
How serious is the interaction between Ethosuximide and Ritonavir?
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 toxicity and serum levels, and reduce the dose as 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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