Drug interactions
Doxycycline + Sodium picosulfate / magnesium oxide / anhydrous citric acid
Severity: Moderate
Doxycycline 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
Magnesium in the bowel preparation chelates doxycycline in the gut and lowers its absorption. Antibiotics may also reduce the bowel-cleansing effect of picosulfate by suppressing the colonic bacteria that activate it.
What this interaction means in plain words
Doxycycline 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
Chelation of doxycycline by magnesium, and antibiotic suppression of colonic flora needed to convert picosulfate to its active form.
What to do
Take doxycycline at least 2 hours before and not sooner than 6 hours after the bowel preparation. Consider whether the antibiotic course can be deferred around colonoscopy preparation.
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 Doxycycline
- Acitretin + Doxycycline Contraindicated
- Aminolevulinic acid + Doxycycline Major
- Cholera vaccine + Doxycycline Major
- Doxycycline + Isotretinoin Major
- Doxycycline + Methoxyflurane Major
- Doxycycline + Microbiota Major
Frequently asked questions
Can I take Doxycycline with Sodium picosulfate / magnesium oxide / anhydrous citric acid?
MediHelp rates the interaction as moderate. Doxycycline 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. Magnesium in the bowel preparation chelates doxycycline in the gut and lowers its absorption. Antibiotics may also reduce the bowel-cleansing effect of picosulfate by suppressing the colonic bacteria that activate it.
How serious is the interaction between Doxycycline 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: Take doxycycline at least 2 hours before and not sooner than 6 hours after the bowel preparation. Consider whether the antibiotic course can be deferred around colonoscopy preparation.
What other medicines interact with Doxycycline?
MediHelp also lists interactions of Doxycycline with, for example, Acitretin, Aminolevulinic acid, Cholera vaccine. The full list is on the Doxycycline page.
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