Ampicillin Injection and Pantoprazole: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Jul 11, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Ampicillin Injection
Pantoprazole
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.
What happens
Loss of ampicillin efficacy
Interaction Deep Dive
Pantoprazole produces extensive and long lasting inhibition of gastric acid secretion. For some drugs, including ampicillin, absorption from the GI tract is enhanced by the presence of gastric acid. When ampicillin is coadministered with pantoprazole, reduced acidity may compromise ampicillin absorption, thus decreasing its bioavailability12.
Why it happens (mechanism)
Decreased gastrointestinal absorption
Common questions
Can I take Ampicillin Injection and Pantoprazole together?
Loss of ampicillin efficacy Always confirm with your pharmacist or prescriber before making any change.
How serious is the Ampicillin Injection and Pantoprazole interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
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 Ampicillin Injection or Pantoprazole 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 anything you'd monitor while I'm on both?
References (2)
- Product Information: PROTONIX(R) delayed-release oral tablets, suspension, pantoprazole sodium delayed-release oral tablets, suspension. Wyeth Pharmaceuticals,Inc, Philadelphia, PA, 2008. DailyMed
- Product Information: PROTONIX(R) IV injection, pantoprazole sodium IV injection. Wyeth Pharmaceuticals,Inc, Philadelphia, PA, 2007.
Keep reading about Ampicillin Injection
Keep reading about Pantoprazole
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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