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Drug interactions

Ampicillin + Dienogest / estradiol valerate

Severity: Minor

Ampicillin and Dienogest / estradiol valerate: minor 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

Antibiotics were once thought to lower oral contraceptive hormone levels by disrupting gut flora that recirculate estrogens. Controlled data show no consistent reduction in hormone levels with non-rifamycin antibiotics such as ampicillin, so a clinically significant loss of effect is unlikely.

What this interaction means in plain words

Ampicillin and Dienogest / estradiol valerate have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.

Evidence level: Low

Why it happens

Theoretical reduction of enterohepatic recirculation of estrogen through altered intestinal flora.

What to do

No additional contraception is routinely required; advise additional precautions only if vomiting or severe diarrhea occurs.

What to ask your pharmacist

  • Is there anything I should notice while taking both?
  • Do I need to tell my doctor at the next visit?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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Frequently asked questions

Can I take Ampicillin with Dienogest / estradiol valerate?

MediHelp rates the interaction as minor. Ampicillin and Dienogest / estradiol valerate have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Antibiotics were once thought to lower oral contraceptive hormone levels by disrupting gut flora that recirculate estrogens. Controlled data show no consistent reduction in hormone levels with non-rifamycin antibiotics such as ampicillin, so a clinically significant loss of effect is unlikely.

How serious is the interaction between Ampicillin and Dienogest / estradiol valerate?

MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No additional contraception is routinely required; advise additional precautions only if vomiting or severe diarrhea occurs.

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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