Omeprazole and Phenytoin: Drug Interaction Guide

Quick answer: This combination requires caution. Omeprazole and Phenytoin can be used together with adjustments and monitoring.

Interaction severity: Moderate — caution required

How Omeprazole interacts with Phenytoin

Omeprazole can inhibit CYP2C19, reducing phenytoin metabolism in some patients. Increased phenytoin concentrations may cause dose-related neurotoxicity.

What you should do

Monitor phenytoin levels and clinical toxicity after starting or stopping omeprazole. Consider pantoprazole if a proton pump inhibitor is required.

Key facts

Severity

Moderate — caution required

Mechanism

Omeprazole can inhibit CYP2C19, reducing phenytoin metabolism in some patients. Increased phenytoin concentrations may c...

Action

Monitor phenytoin levels and clinical toxicity after starting or stopping omeprazole. Consider pantoprazole if a proton ...

Important medical disclaimer: This page provides educational information about drug interactions for general reference. It is not a substitute for professional medical advice, diagnosis, or treatment. Always discuss your specific medications with a qualified healthcare provider before starting, stopping, or changing any treatment. About our editorial team.

Frequently asked questions

Can I take Omeprazole and Phenytoin together?

With caution. Monitor phenytoin levels and clinical toxicity after starting or stopping omeprazole. Consider pantoprazole if a proton pump inhibitor is required.

What is the severity of this interaction?

The interaction between Omeprazole and Phenytoin is classified as Moderate — caution required. Omeprazole can inhibit CYP2C19, reducing phenytoin metabolism in some patients. Increased phenytoin concentrations may cause dose-related neurotoxicity.

What should I do if I'm prescribed both?

Monitor phenytoin levels and clinical toxicity after starting or stopping omeprazole. Consider pantoprazole if a proton pump inhibitor is required. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

Last reviewed: by iMedic Medical Editorial Team. Our editorial process.