Omeprazole and Delavirdine: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Delavirdine
Omeprazole
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
Here's what's going on. Delavirdine (Rescriptor) is an HIV medicine that needs an acidic stomach to dissolve and get absorbed properly. Omeprazole (Prilosec) lowers stomach acid. When you take them together, your body may absorb less of the delavirdine, so the amount in your blood can drop.
Why that matters: with HIV medicines, you need steady, adequate levels to keep the virus controlled. If levels fall too low, the medicine may not work as well. This is based on how the drugs behave, not on a formal study, but it's taken seriously. The good news is your care team can plan around this, so talk with your pharmacist or doctor before combining them.
Effect: Reduced delavirdine serum concentrations, with potential loss of antiretroviral efficacy.
Mechanism: Omeprazole raises gastric pH; delavirdine absorption is pH-dependent (requires an acidic environment for dissolution). Elevated pH reduces dissolution and absorption, lowering delavirdine AUC/Cmax. Neither agent is activated by the other's pathway here; this is a PK absorption interaction, not enzyme-mediated.
- Direction: Decreased delavirdine exposure
- Onset: Unspecified
- Evidence: Theoretical, not clinically evaluated
- Severity: Major
Management: Chronic concurrent omeprazole is not recommended. If acid suppression is needed, discuss alternatives and closer monitoring of virologic response with the care team.
What happens
Reduced serum delavirdine levels
Interaction Deep Dive
Omeprazole is a proton pump inhibitor that raises gastric pH, and giving it at the same time as delavirdine may impair the absorption of delavirdine, leading to lower serum concentrations of delavirdine and possibly a loss of effectiveness. This interaction has not been assessed clinically; nevertheless, taking omeprazole long term together with delavirdine is not advised1.
Why it happens (mechanism)
Reduced absorption of delavirdine due to increase in gastric pH
How to manage this interaction
Keep taking both medicines as prescribed until you have spoken with your care team. Do not stop or change anything on your own.
- Because omeprazole lowers stomach acid, chronic use alongside delavirdine is generally not recommended, since it can reduce how much delavirdine your body absorbs.
- Tell your pharmacist or prescriber that you take both, including any over-the-counter Prilosec OTC.
- Your team may choose a different approach for acid or heartburn, or monitor how well your HIV treatment is working, and will individualize the plan for you.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Omeprazole and Delavirdine together?
Omeprazole can lower delavirdine levels by reducing its absorption, which may weaken HIV control, so chronic use together is not recommended. Talk with your pharmacist or doctor before combining them. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Omeprazole and Delavirdine interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Omeprazole and Delavirdine interaction managed?
Keep taking both medicines as prescribed until you have spoken with your care team. Do not stop or change anything on your own. Because omeprazole lowers stomach acid, chronic use alongside delavirdine is generally not recommended, since it can reduce how much delavirdine your body absorbs. Tell your pharmacist or prescriber that you take both, including any over-the-counter Prilosec OTC. Your tea… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Omeprazole or Delavirdine need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (1)
- Product Information: RESCRIPTOR(R) oral tablets, delavirdine mesylate oral tablets. Pfizer,Inc, New York, NY, 2006.
Keep reading about Delavirdine
Keep reading about Omeprazole
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist