Drug interactions
Ketoconazole + Levonorgestrel oral / ethinylestradiol / ferrous bisglycinate
Severity: Moderate
Ketoconazole and Levonorgestrel oral / ethinylestradiol / ferrous bisglycinate: 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 may increase plasma levels of ethinylestradiol and levonorgestrel, potentially increasing hormonal adverse effects such as breast tenderness, nausea and breakthrough bleeding. Clinically important loss of contraceptive efficacy is not expected.
What this interaction means in plain words
Ketoconazole and Levonorgestrel oral / ethinylestradiol / ferrous bisglycinate 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.
Why it happens
Ketoconazole inhibits CYP3A4 metabolism of the estrogen and progestin components.
What to do
Monitor for estrogenic and progestogenic adverse effects, including thromboembolic risk factors and blood pressure, during prolonged ketoconazole use; consider an alternative contraceptive if tolerability is poor.
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 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 Ketoconazole with Levonorgestrel oral / ethinylestradiol / ferrous bisglycinate?
MediHelp rates the interaction as moderate. Ketoconazole and Levonorgestrel oral / ethinylestradiol / ferrous bisglycinate 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 may increase plasma levels of ethinylestradiol and levonorgestrel, potentially increasing hormonal adverse effects such as breast tenderness, nausea and breakthrough bleeding. Clinically important loss of contraceptive efficacy is not expected.
How serious is the interaction between Ketoconazole and Levonorgestrel oral / ethinylestradiol / ferrous bisglycinate?
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 and progestogenic adverse effects, including thromboembolic risk factors and blood pressure, during prolonged ketoconazole use; consider an alternative contraceptive if tolerability is poor.
What other medicines interact with Ketoconazole?
MediHelp also lists interactions of Ketoconazole with, for example, Alfuzosin, Alprazolam, Avanafil. The full list is on the Ketoconazole page.
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