Drug interactions
Erythromycin + Ethinylestradiol
Severity: Minor
Erythromycin and Ethinylestradiol: 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 traditionally thought to reduce oral contraceptive efficacy by disrupting gut flora, but controlled data do not show a meaningful loss of efficacy with macrolides. Erythromycin may also slightly raise ethinylestradiol levels via CYP3A4 inhibition.
What this interaction means in plain words
Erythromycin and Ethinylestradiol 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 recycling of estrogen by altered gut flora, which is unproven for erythromycin.
What to do
No routine change to contraception is required. Advise backup contraception 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?
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Other interactions of Erythromycin
- Conivaptan + Erythromycin Contraindicated
- Dihydroergotamine intranasal + Erythromycin Contraindicated
- Dihydroergotamine + Erythromycin Contraindicated
- Domperidone + Erythromycin Contraindicated
- Dronedarone + Erythromycin Contraindicated
- Droperidol + Erythromycin Contraindicated
Frequently asked questions
Can I take Erythromycin with Ethinylestradiol?
MediHelp rates the interaction as minor. Erythromycin and Ethinylestradiol 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 traditionally thought to reduce oral contraceptive efficacy by disrupting gut flora, but controlled data do not show a meaningful loss of efficacy with macrolides. Erythromycin may also slightly raise ethinylestradiol levels via CYP3A4 inhibition.
How serious is the interaction between Erythromycin and Ethinylestradiol?
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 routine change to contraception is required. Advise backup contraception if vomiting or severe diarrhea occurs.
What other medicines interact with Erythromycin?
MediHelp also lists interactions of Erythromycin with, for example, Conivaptan, Dihydroergotamine intranasal, Dihydroergotamine. The full list is on the Erythromycin page.
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