Drug interactions
Ampicillin + Sodium picosulfate / magnesium oxide / anhydrous citric acid
Severity: Moderate
Ampicillin and Sodium picosulfate / magnesium oxide / anhydrous citric acid: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Sodium picosulfate is a prodrug activated by colonic bacteria, and antibacterial agents can reduce this conversion. Oral ampicillin before bowel preparation may therefore weaken the laxative effect and result in inadequate cleansing before colonoscopy.
What this interaction means in plain words
Ampicillin and Sodium picosulfate / magnesium oxide / anhydrous citric acid can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Antibiotic suppression of colonic flora needed to convert picosulfate to its active metabolite.
What to do
Where possible, avoid giving the antibiotic before or during bowel preparation and complete the preparation before starting it; check the quality of bowel cleansing and consider an alternative preparation if the antibiotic cannot be delayed.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Ampicillin
- Allopurinol + Ampicillin Moderate
- Ampicillin + Bcg vaccine live Moderate
- Ampicillin + Chloramphenicol Moderate
- Ampicillin + Chloroquine Moderate
- Ampicillin + Cholera vaccine Moderate
- Ampicillin + Demeclocycline Moderate
Frequently asked questions
Can I take Ampicillin with Sodium picosulfate / magnesium oxide / anhydrous citric acid?
MediHelp rates the interaction as moderate. Ampicillin and Sodium picosulfate / magnesium oxide / anhydrous citric acid can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Sodium picosulfate is a prodrug activated by colonic bacteria, and antibacterial agents can reduce this conversion. Oral ampicillin before bowel preparation may therefore weaken the laxative effect and result in inadequate cleansing before colonoscopy.
How serious is the interaction between Ampicillin and Sodium picosulfate / magnesium oxide / anhydrous citric acid?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Where possible, avoid giving the antibiotic before or during bowel preparation and complete the preparation before starting it; check the quality of bowel cleansing and consider an alternative preparation if the antibiotic cannot be delayed.
What other medicines interact with Ampicillin?
MediHelp also lists interactions of Ampicillin with, for example, Allopurinol, Bcg vaccine live, Chloramphenicol. The full list is on the Ampicillin page.
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