Drug interactions
Dicloxacillin + Ethinylestradiol
Severity: Minor
Dicloxacillin 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 have long been suspected of reducing the effectiveness of combined oral contraceptives, but controlled data show that non-rifamycin antibiotics such as penicillins do not consistently lower hormone levels or raise ovulation. Any risk of contraceptive failure is considered very low.
What this interaction means in plain words
Dicloxacillin 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 gut flora that deconjugate estrogen metabolites and so limit enterohepatic recycling of ethinylestradiol; not confirmed for penicillins.
What to do
No routine additional contraception is needed for short penicillin courses; advise the patient to continue pill use and to use backup 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 Dicloxacillin
- Dicloxacillin + Phenindione Major
- Atogepant + Dicloxacillin Moderate
- Axitinib + Dicloxacillin Moderate
- Bcg vaccine live + Dicloxacillin Moderate
- Cholera vaccine + Dicloxacillin Moderate
- Demeclocycline + Dicloxacillin Moderate
Frequently asked questions
Can I take Dicloxacillin with Ethinylestradiol?
MediHelp rates the interaction as minor. Dicloxacillin 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 have long been suspected of reducing the effectiveness of combined oral contraceptives, but controlled data show that non-rifamycin antibiotics such as penicillins do not consistently lower hormone levels or raise ovulation. Any risk of contraceptive failure is considered very low.
How serious is the interaction between Dicloxacillin 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 additional contraception is needed for short penicillin courses; advise the patient to continue pill use and to use backup if vomiting or severe diarrhea occurs.
What other medicines interact with Dicloxacillin?
MediHelp also lists interactions of Dicloxacillin with, for example, Phenindione, Atogepant, Axitinib. The full list is on the Dicloxacillin page.
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