Omeprazole and Taletrectinib: 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
Omeprazole
Taletrectinib
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 the key thing: Taletrectinib (Ibtrozi) is a cancer medicine that needs an acidic stomach to dissolve and get absorbed properly. Omeprazole (Prilosec) lowers stomach acid. When you take them together, less of the cancer medicine gets into your body, so it may not work as well.
In studies, taking omeprazole cut the peak level of taletrectinib by about 65% and the total amount absorbed by about 40%. That's a big drop, and with a cancer treatment you really want the full effect. Please don't change anything on your own. Talk with your oncology team or pharmacist so they can help you manage your stomach symptoms without weakening your cancer treatment.
Interaction: Omeprazole (PPI) reduces taletrectinib exposure via a pharmacokinetic, pH-dependent absorption mechanism. Taletrectinib has pH-dependent aqueous solubility; raising gastric pH decreases dissolution and absorption.
- Direction: Reduced taletrectinib effect (subtherapeutic exposure, possible efficacy loss).
- Magnitude: With omeprazole 40 mg daily, taletrectinib Cmax fell ~65% and AUC ~40%.
- Evidence: Probable; severity major; onset unspecified.
- Management: Avoid concomitant PPI use. Consider acid-suppression alternatives per oncology guidance and monitor for reduced antitumor response.
Neither agent's activation depends on this mechanism; the concern is loss of taletrectinib absorption, not toxicity.
What happens
Reduced taletrectinib exposure and reduced efficacy of taletrectinib
Interaction Deep Dive
Do not use taletrectinib together with proton pump inhibitors, because this combination can lower taletrectinib exposure and thereby diminish its efficacy. The aqueous solubility of taletrectinib is pH-dependent. When omeprazole (a PPI) was given at 40 mg once daily alongside taletrectinib, the taletrectinib Cmax fell by 65% and its AUC dropped by 40%1.
Why it happens (mechanism)
Changes in gastric pH
How to manage this interaction
What your care team may do:
- Generally, avoiding this combination is preferred because the PPI can meaningfully lower how much taletrectinib your body absorbs.
- Your team may look at other ways to control acid-related symptoms that don't reduce your cancer medicine's effect.
- They may monitor you more closely to be sure the taletrectinib is still working.
What you should do: Keep taking both exactly as prescribed for now, and don't stop or change either one on your own. Let your oncologist or pharmacist know you're on omeprazole (or any acid reducer, including over-the-counter ones) so they can tailor the plan for you.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) The aqueous solubility of taletrectinib is pH-dependent. When omeprazole (a PPI) 40 mg daily was used concurrently, taletrectinib Cmax was reduced by 65% and AUC was reduced by 40% 1.
Common questions
Can I take Omeprazole and Taletrectinib together?
Omeprazole can significantly lower how much taletrectinib your body absorbs, which may weaken this cancer treatment, so this combination is usually avoided. Tell your oncology team about any acid reducer you take so they can adjust the plan. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Omeprazole and Taletrectinib 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 Taletrectinib interaction managed?
What your care team may do: Generally, avoiding this combination is preferred because the PPI can meaningfully lower how much taletrectinib your body absorbs. Your team may look at other ways to control acid-related symptoms that don't reduce your cancer medicine's effect. They may monitor you more closely to be sure the taletrectinib is still working. What you should do: Keep taking both exactly… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
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 Taletrectinib 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: IBTROZI(TM) oral capsules, taletrectinib oral capsules. Nuvation Bio Inc. (per Manufacturer), Burlington, MA, 2025. DailyMed
Keep reading about Omeprazole
Keep reading about Taletrectinib
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.
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