Drug interactions
Erythromycin lactobionate + Ethinyl estradiol-norgestimate
Severity: Minor
Erythromycin lactobionate and Ethinyl estradiol-norgestimate: 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 have been suspected of lowering contraceptive effectiveness through effects on gut flora, but pharmacokinetic data for macrolides do not show a consistent meaningful reduction. Erythromycin may in theory slightly raise estrogen levels through CYP3A4 inhibition.
What this interaction means in plain words
Erythromycin lactobionate and Ethinyl estradiol-norgestimate have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Erythromycin lactobionate belongs to Anti Bacterial; Ethinyl estradiol-norgestimate belongs to Endocrine.
Why it happens
Proposed alteration of gut flora affecting estrogen recirculation, which is unproven; weak CYP3A4 inhibition may act in the opposite direction.
What to do
No routine change is needed. Advise backup contraception only if vomiting or severe diarrhea impairs absorption.
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 Ethinyl estradiol-norgestimate
- Ethinyl estradiol-norgestimate + Fezolinetant Contraindicated
- Ethinyl estradiol-norgestimate + Ombitasvir / paritaprevir / ritonavir and dasabuvir Contraindicated
- Ethinyl estradiol-norgestimate + Tranexamic acid Contraindicated
- Aminocaproic acid + Ethinyl estradiol-norgestimate Major
- Amobarbital + Ethinyl estradiol-norgestimate Major
- Anastrozole + Ethinyl estradiol-norgestimate Major
Other interactions of Erythromycin lactobionate
- Cisapride + Erythromycin lactobionate Contraindicated
- Dihydroergotamine + Erythromycin lactobionate Contraindicated
- Dronedarone + Erythromycin lactobionate Contraindicated
- Eletriptan + Erythromycin lactobionate Contraindicated
- Ergotamine + Erythromycin lactobionate Contraindicated
- Erythromycin lactobionate + Flibanserin Contraindicated
Frequently asked questions
Can I take Erythromycin lactobionate with Ethinyl estradiol-norgestimate?
MediHelp rates the interaction as minor. Erythromycin lactobionate and Ethinyl estradiol-norgestimate 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 have been suspected of lowering contraceptive effectiveness through effects on gut flora, but pharmacokinetic data for macrolides do not show a consistent meaningful reduction. Erythromycin may in theory slightly raise estrogen levels through CYP3A4 inhibition.
How serious is the interaction between Erythromycin lactobionate and Ethinyl estradiol-norgestimate?
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 is needed. Advise backup contraception only if vomiting or severe diarrhea impairs absorption.
What other medicines interact with Ethinyl estradiol-norgestimate?
MediHelp also lists interactions of Ethinyl estradiol-norgestimate with, for example, Fezolinetant, Ombitasvir / paritaprevir / ritonavir and dasabuvir, Tranexamic acid. The full list is on the Ethinyl estradiol-norgestimate page.
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