Drug interactions
Omeprazole + Phenobarbital
Severity: Moderate
Omeprazole and Phenobarbital: 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
Phenobarbital induces CYP2C19 and CYP3A4, which lowers omeprazole concentrations. Acid suppression may become inadequate.
What this interaction means in plain words
Omeprazole and Phenobarbital 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
Enzyme induction by phenobarbital increases omeprazole metabolism.
What to do
Monitor for reduced acid suppression and increase the omeprazole 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 Omeprazole
- Mavacamten + Omeprazole Contraindicated
- Omeprazole + Rilpivirine Contraindicated
- Acalabrutinib + Omeprazole Major
- Atazanavir + Omeprazole Major
- Citalopram + Omeprazole Major
- Clopidogrel + Omeprazole Major
Frequently asked questions
Can I take Omeprazole with Phenobarbital?
MediHelp rates the interaction as moderate. Omeprazole and Phenobarbital 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. Phenobarbital induces CYP2C19 and CYP3A4, which lowers omeprazole concentrations. Acid suppression may become inadequate.
How serious is the interaction between Omeprazole and Phenobarbital?
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 reduced acid suppression and increase the omeprazole dose if needed.
What other medicines interact with Omeprazole?
MediHelp also lists interactions of Omeprazole with, for example, Mavacamten, Rilpivirine, Acalabrutinib. The full list is on the Omeprazole page.
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