Does Gabapentin Interact With Phenytoin?

Phenytoin In a single (400 mg) and multiple dose (400 mg three times a day) study of Gabapentin in epileptic patients (N=8) maintained on phenytoin monotherapy for at least 2 months, gabapentin had no effect on the steady-state trough plasma concentrations of phenytoin and phenytoin had no effect on gabapentin pharmacokinetics.

Severity: Minor

Severity basis: drug interactions section. Combining Gabapentin (Gabapentinoid anticonvulsant) and Phenytoin (Anticonvulsant) is classified as a minor interaction.

What to Do

This is generally a minor interaction, but review it with your pharmacist to be sure it is safe for you.

From the FDA Label

Phenytoin In a single (400 mg) and multiple dose (400 mg three times a day) study of Gabapentin in epileptic patients (N=8) maintained on phenytoin monotherapy for at least 2 months, gabapentin had no effect on the steady-state trough plasma concentrations of phenytoin and phenytoin had no effect on gabapentin pharmacokinetics.

Source: FDA structured product labeling (set_id 01b810b7-f4c8-4412-bbc5-b9220d8770d8).

Gabapentin

Gabapentinoid anticonvulsant

Brands: Neurontin, Gralise

View Gabapentin safety profile

Phenytoin

Anticonvulsant

Brands: Dilantin

View Phenytoin safety profile

Check these against your full medication list in our free Interaction Checker

This information is educational — not medical advice.

This page is provided for general educational purposes and summarizes publicly available data from sources such as the U.S. Food & Drug Administration. It is not a substitute for the judgment of a licensed clinician and should not be used to start, stop, or change any medication. It may be incomplete or out of date, and individual circumstances vary. Always talk with your prescriber or pharmacist about your specific medications and health conditions. If you think you may have a medical emergency, call 911.

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