Drug interactions
Ethinylestradiol + Penicillin g
Severity: Minor
Ethinylestradiol and Penicillin g: 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
Penicillins have been theorized to lower ethinylestradiol exposure by disrupting gut flora involved in estrogen recycling, but pharmacokinetic studies have generally not shown meaningful reductions. Contraceptive failure is rare and unproven.
What this interaction means in plain words
Ethinylestradiol and Penicillin g have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Theoretical reduction of enterohepatic recirculation of ethinylestradiol via altered intestinal flora; not confirmed.
What to do
No additional contraception is routinely needed; counsel on missed doses and on vomiting or severe diarrhea.
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?
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Other interactions of Penicillin g
- Amifampridine + Penicillin g Moderate
- Amiloride + Penicillin g Moderate
- Bcg vaccine live + Penicillin g Moderate
- Cholera vaccine + Penicillin g Moderate
- Colestipol + Penicillin g Moderate
- Deflazacort + Penicillin g Moderate
Frequently asked questions
Can I take Ethinylestradiol with Penicillin g?
MediHelp rates the interaction as minor. Ethinylestradiol and Penicillin g have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Penicillins have been theorized to lower ethinylestradiol exposure by disrupting gut flora involved in estrogen recycling, but pharmacokinetic studies have generally not shown meaningful reductions. Contraceptive failure is rare and unproven.
How serious is the interaction between Ethinylestradiol and Penicillin g?
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 needed; counsel on missed doses and on vomiting or severe diarrhea.
What other medicines interact with Penicillin g?
MediHelp also lists interactions of Penicillin g with, for example, Amifampridine, Amiloride, Bcg vaccine live. The full list is on the Penicillin g page.
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