Drug interactions
Ethinyl estradiol-levonorgestrel + Ketoconazole
Severity: Moderate
Ethinyl estradiol-levonorgestrel and Ketoconazole: moderate 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
Ketoconazole, a strong CYP3A4 inhibitor, can increase exposure to ethinyl estradiol and levonorgestrel. This may increase estrogen-related adverse effects and, in theory, thrombotic risk.
What this interaction means in plain words
Ethinyl estradiol-levonorgestrel and Ketoconazole can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Ethinyl estradiol-levonorgestrel belongs to Endocrine; Ketoconazole belongs to Anti Fungals.
Why it happens
Ketoconazole inhibits CYP3A4-mediated metabolism of ethinyl estradiol and levonorgestrel.
What to do
Monitor for estrogenic or progestogenic adverse effects and breakthrough bleeding. Consider an alternative antifungal or contraceptive if prolonged treatment is needed.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Ethinyl estradiol-levonorgestrel
- Ethinyl estradiol-levonorgestrel + Fezolinetant Contraindicated
- Ethinyl estradiol-levonorgestrel + Ombitasvir / paritaprevir / ritonavir and dasabuvir Contraindicated
- Ethinyl estradiol-levonorgestrel + Tranexamic acid Contraindicated
- Aminocaproic acid + Ethinyl estradiol-levonorgestrel Major
- Amobarbital + Ethinyl estradiol-levonorgestrel Major
- Anastrozole + Ethinyl estradiol-levonorgestrel Major
Other interactions of Ketoconazole
- Alfuzosin + Ketoconazole Contraindicated
- Alprazolam + Ketoconazole Contraindicated
- Avanafil + Ketoconazole Contraindicated
- Conivaptan + Ketoconazole Contraindicated
- Dihydroergotamine intranasal + Ketoconazole Contraindicated
- Dihydroergotamine + Ketoconazole Contraindicated
Frequently asked questions
Can I take Ethinyl estradiol-levonorgestrel with Ketoconazole?
MediHelp rates the interaction as moderate. Ethinyl estradiol-levonorgestrel and Ketoconazole can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Ketoconazole, a strong CYP3A4 inhibitor, can increase exposure to ethinyl estradiol and levonorgestrel. This may increase estrogen-related adverse effects and, in theory, thrombotic risk.
How serious is the interaction between Ethinyl estradiol-levonorgestrel and Ketoconazole?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for estrogenic or progestogenic adverse effects and breakthrough bleeding. Consider an alternative antifungal or contraceptive if prolonged treatment is needed.
What other medicines interact with Ethinyl estradiol-levonorgestrel?
MediHelp also lists interactions of Ethinyl estradiol-levonorgestrel with, for example, Fezolinetant, Ombitasvir / paritaprevir / ritonavir and dasabuvir, Tranexamic acid. The full list is on the Ethinyl estradiol-levonorgestrel page.
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