Drug interactions
Efavirenz + Omeprazole
Severity: Moderate
Efavirenz and Omeprazole: 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
Efavirenz induces CYP2C19 and CYP3A4 and may lower omeprazole exposure, possibly reducing acid suppression. Efavirenz also has some inhibitory effect on CYP2C19, so the net effect is unpredictable.
What this interaction means in plain words
Efavirenz and Omeprazole 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.
Efavirenz belongs to Anti Virals; Omeprazole belongs to Gastrointestinal Tract.
Why it happens
Mixed induction and inhibition of CYP2C19 and CYP3A4 by efavirenz alters omeprazole metabolism.
What to do
Monitor for reduced acid suppression and symptom control, and increase omeprazole dose if symptoms persist.
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
Other interactions of Efavirenz
- Cobimetinib + Efavirenz Contraindicated
- Dienogest / estradiol valerate + Efavirenz Contraindicated
- Dihydroergotamine intranasal + Efavirenz Contraindicated
- Dihydroergotamine + Efavirenz Contraindicated
- Doravirine + Efavirenz Contraindicated
- Efavirenz + Elbasvir / grazoprevir Contraindicated
Frequently asked questions
Can I take Efavirenz with Omeprazole?
MediHelp rates the interaction as moderate. Efavirenz and Omeprazole 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. Efavirenz induces CYP2C19 and CYP3A4 and may lower omeprazole exposure, possibly reducing acid suppression. Efavirenz also has some inhibitory effect on CYP2C19, so the net effect is unpredictable.
How serious is the interaction between Efavirenz and Omeprazole?
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 symptom control, and increase omeprazole dose if symptoms persist.
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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