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Drug interactions

Ethosuximide + Fentanyl iontophoretic transdermal system

Severity: Major

Ethosuximide and Fentanyl iontophoretic transdermal system: major 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

Fentanyl and ethosuximide both depress the CNS. Together they can cause excessive sedation and respiratory depression.

What this interaction means in plain words

Ethosuximide and Fentanyl iontophoretic transdermal system can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.

Evidence level: Moderate

Why it happens

Additive CNS and respiratory depression.

What to do

Monitor sedation and respiratory status, and use the lowest effective opioid dose. Advise patients to report excessive drowsiness.

What to ask your pharmacist

  • Does the benefit of taking both outweigh the risk in my case?
  • Do I need any blood test, ECG or other check while on both?
  • What early warning signs should I watch for, and what should I do if they appear?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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Frequently asked questions

Can I take Ethosuximide with Fentanyl iontophoretic transdermal system?

MediHelp rates the interaction as major. Ethosuximide and Fentanyl iontophoretic transdermal system can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Fentanyl and ethosuximide both depress the CNS. Together they can cause excessive sedation and respiratory depression.

How serious is the interaction between Ethosuximide and Fentanyl iontophoretic transdermal system?

MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor sedation and respiratory status, and use the lowest effective opioid dose. Advise patients to report excessive drowsiness.

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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