Omeprazole and Sunitinib: 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
Sunitinib
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. Sunitinib (Sutent) is a cancer medicine that needs an acidic stomach to dissolve and be absorbed properly. Omeprazole (Prilosec) lowers stomach acid. When you take them together, the sunitinib may not dissolve as well, so less of it gets into your body. That can make the cancer treatment work less well over time.
Please don't stop or change either medicine on your own. This is something your cancer care team knows how to handle, whether that means adjusting how you take your acid medicine or choosing another option. Just bring it up with your oncologist or pharmacist so they can plan the best approach for you.
Effect: Reduced sunitinib bioavailability, potentially lowering antitumor efficacy.
Mechanism: Sunitinib is a pH-dependent, weakly basic drug; PPI-induced elevation of gastric pH decreases its solubility and absorption. Neither drug is a prodrug here; this is a straightforward absorption effect.
- Direction: Decreased sunitinib exposure/effect.
- Evidence: Probable, from retrospective mRCC data showing reduced OS and PFS.
- Onset: Unspecified (relevant with continuous acid suppression).
- Management: Reassess PPI necessity, consider shortest effective acid suppression or an alternative agent, and monitor clinical/radiographic response. Individualize per oncology team.
What happens
Reduction in sunitinib bioavailability
Interaction Deep Dive
When sunitinib is given together with sustained suppression of gastric acid produced by a proton pump inhibitor (PPI), the antitumor activity of sunitinib may be diminished. This is supported by findings of decreased overall survival and progression-free survival observed in a retrospective analysis of patients who had metastatic renal cell cancer. The observed survival gap indicates that agents that suppress acid may interact with sunitinib by lowering its absorption1.
Why it happens (mechanism)
Decreased solubility and absorption of sunitinib due to increased pH of the upper gastrointestinal tract caused by proton pump inhibitors
How to manage this interaction
Keep taking both medicines as prescribed unless your care team tells you otherwise. The concern is that ongoing acid suppression may lower how much sunitinib your body absorbs.
- Tell your oncologist and pharmacist that you take omeprazole (or any acid reducer, including over-the-counter versions).
- Your team may review whether you still need a PPI, consider a different acid-reducing option, or watch your treatment response more closely.
- Do not start or stop any acid reducer, including OTC ones, without checking first.
The goal is simple: make sure your sunitinib works as well as possible, and your team can tailor this for you.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) In a retrospective analysis of patients with metastatic renal cell carcinoma (N=231), giving sunitinib together with a proton pump inhibitor (PPI) lowered the efficacy of sunitinib. Patients receiving sunitinib along with continuous gastric acid suppression (PPI) showed a significant reduction in progression-free survival (PFS; 18.9 vs 23.6 weeks) and overall survival (OS; 40.9 vs 62.4 weeks) relative to patients who did not receive a PPI during sunitinib therapy. In the patients included in this analysis, neither pharmacokinetics 1 nor drug levels were evaluated during sunitinib treatment.
Common questions
Can I take Omeprazole and Sunitinib together?
Omeprazole can lower how much sunitinib your body absorbs, which may reduce the cancer drug's effectiveness. Tell your oncologist and pharmacist so they can review your acid-reducer use and monitor your response. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Omeprazole and Sunitinib 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 Sunitinib interaction managed?
Keep taking both medicines as prescribed unless your care team tells you otherwise. The concern is that ongoing acid suppression may lower how much sunitinib your body absorbs. Tell your oncologist and pharmacist that you take omeprazole (or any acid reducer, including over-the-counter versions). Your team may review whether you still need a PPI, consider a different acid-reducing option, or watch… 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 Sunitinib 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)
- Ha VH, Ngo M, Chu MP, et al: Does gastric acid suppression affect sunitinib efficacy in patients with advanced or metastatic renal cell cancer?. J Oncol Pharm Pract 2015; 21(3):194-200. PubMed
Keep reading about Sunitinib
Keep reading about Omeprazole
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