Omeprazole and Pazopanib: 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
Pazopanib
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.
Pazopanib (Votrient) is a cancer medicine that needs an acidic stomach to dissolve and get absorbed properly. Omeprazole (Prilosec) is an acid reducer, and it lowers your stomach acid for a long stretch of the day. When you take them together, your body may absorb less pazopanib, which means you could get too little of an important cancer treatment.
This is a well-documented interaction, so it matters. The good news is your care team knows how to handle it. Please don't stop or change either medicine on your own. Instead, talk with your oncologist or pharmacist so they can find the safest plan for you.
Effect: Reduced pazopanib bioavailability (decreased AUC and Cmax), risking subtherapeutic exposure. Neither drug is a prodrug; this is a pH-dependent absorption interaction.
Mechanism: Omeprazole raises gastric pH; pazopanib solubility and absorption are pH-dependent and decline in a less acidic environment. Chronic PPI dosing sustains elevated pH.
Evidence: Established (PK data with esomeprazole). One mRCC study showed no significant PFS/OS impact.
- Avoid concomitant use where possible.
- If necessary, dose pazopanib when gastric pH is lowest (eg, late evening).
- Prefer short-acting antacids, separated from pazopanib by several hours.
What happens
Reduction in pazopanib bioavailability
Interaction Deep Dive
Taking oral pazopanib alongside a proton pump inhibitor can lower pazopanib levels. Coadministration of pazopanib with esomeprazole produced a reduction in the mean AUC and Cmax of pazopanib. Because pazopanib relies on an acidic environment for its solubility and absorption, and because repeated dosing of a proton pump inhibitor raises gastric pH over a prolonged interval, giving the two together diminishes pazopanib absorption, potentially leading to subtherapeutic pazopanib exposure in certain patients. Their combined use should be avoided. When coadministration cannot be avoided, alternative dosing schedules that do not raise gastric pH at the moment pazopanib is given may be considered (for example, dosing pazopanib in the late evening)1. Nevertheless, a separate study found no meaningful impact on PFS or OS when the drugs were coadministered in patients with metastatic renal cell carcinoma 3. Short acting antacids may be an option to consider. A gap of several hours should be maintained between administration of pazopanib and antacids 2.
Why it happens (mechanism)
Decreased solubility and absorption of pazopanib due to increased gastric pH by proton pump inhibitors
How to manage this interaction
Keep taking both medicines exactly as prescribed until your care team advises otherwise. Here is what teams typically do with this combination:
- Avoid using them together when possible, since the acid reducer can lower how much pazopanib you absorb.
- If both are truly needed, your team may adjust the timing so pazopanib is taken when stomach acid is naturally higher (such as late evening).
- A short-acting antacid may be considered instead of omeprazole, taken several hours apart from your pazopanib dose.
Ask your oncologist or pharmacist which option fits you before making any change.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
2 reports — tap to read
a) A retrospective cohort study of patients with metastatic renal cell carcinoma found that concurrent use (n=66) of pazopanib with a proton pump inhibitor (esomeprazole, lansoprazole, omeprazole, pantoprazole) or a histamine-2 receptor antagonist (famotidine, ranitidine), compared with pazopanib on its own (n=24), did not produce a significant decrease in progression-free survival (PFS; 9 vs 11 months) or overall survival (OS; 28 vs 30.1 months). Likewise, no significant difference was observed between patients given a proton pump inhibitor (n=57) and those given a histamine-2 receptor antagonist (n=9) with respect to median PFS (11 vs 8 months) or median OS (27 vs 31 months) 3.
b) Giving pazopanib together with esomeprazole produced reductions in pazopanib mean AUC 24 hours post-dose (848 to 512 mcg x hr/mL) and mean Cmax (48.9 to 28.4 mcg/mL). Plasma samples were evaluated for 12 patients with advanced solid tumors who took oral pazopanib 800 mg once daily in the morning (at least 1 hour before or 2 hours after the morning meal) for 7 days and subsequently took esomeprazole 40 mg once daily in the evening (at bedtime, roughly 3 hours after the evening meal) for 5 days. The mean AUC 24 hours post-dose and Cmax for pazopanib metabolites were likewise reduced when esomeprazole was present. Using esomeprazole at the same time may lead to subtherapeutic pazopanib exposure in some patients 1.
Common questions
Can I take Omeprazole and Pazopanib together?
Omeprazole can reduce how much pazopanib your body absorbs, possibly weakening this cancer treatment, so ask your oncologist or pharmacist about timing changes or a different acid reducer before changing anything. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Omeprazole and Pazopanib 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 Pazopanib interaction managed?
Keep taking both medicines exactly as prescribed until your care team advises otherwise. Here is what teams typically do with this combination: Avoid using them together when possible, since the acid reducer can lower how much pazopanib you absorb. If both are truly needed, your team may adjust the timing so pazopanib is taken when stomach acid is naturally higher (such as late evening). A short-a… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "established". Well documented — supported by controlled studies or strong clinical data.
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 Pazopanib 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 (3)
- Tan AR, Gibbon DG, Stein MN, et al: Effects of ketoconazole and esomeprazole on the pharmacokinetics of pazopanib in patients with solid tumors. Cancer Chemother Pharmacol 2013; 71(6):1635-1643. PubMed
- Product Information: VOTRIENT(R) oral tablets, pazopanib oral tablets. GlaxoSmithKline (per FDA), Research Triangle Park, NC, 2014. DailyMed
- McAlister RK, Aston J, Pollack M, et al: Effect of concomitant ph-elevating medications with pazopanib on progression-free survival and overall survival in patients with metastatic renal cell carcinoma. Oncologist 2018; 23(6):686-692. PubMed
Keep reading about Pazopanib
Keep reading about Omeprazole
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