Drug interactions
Ketoconazole + Ospemifene
Severity: Major
Ketoconazole and Ospemifene: major 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 raises ospemifene exposure markedly in pharmacokinetic studies, which may increase estrogen-agonist adverse effects including venous thromboembolism and endometrial effects.
What this interaction means in plain words
Ketoconazole and Ospemifene can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Ketoconazole belongs to Anti Fungals; Ospemifene belongs to Endocrine.
Why it happens
Ketoconazole inhibits CYP3A4 (and CYP2C9 contribution) metabolism of ospemifene.
What to do
Avoid long-term co-administration with strong CYP3A4 inhibitors; if short-term use is unavoidable, monitor for thromboembolic and other adverse effects.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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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
Other interactions of Ospemifene
- Bazedoxifene-conjugated estrogens + Ospemifene Contraindicated
- Estradiol + Ospemifene Contraindicated
- Clomiphene + Ospemifene Major
- Fluconazole + Ospemifene Major
- Ospemifene + Raloxifene Major
- Ospemifene + Rifampicin Major
Frequently asked questions
Can I take Ketoconazole with Ospemifene?
MediHelp rates the interaction as major. Ketoconazole and Ospemifene can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Ketoconazole raises ospemifene exposure markedly in pharmacokinetic studies, which may increase estrogen-agonist adverse effects including venous thromboembolism and endometrial effects.
How serious is the interaction between Ketoconazole and Ospemifene?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid long-term co-administration with strong CYP3A4 inhibitors; if short-term use is unavoidable, monitor for thromboembolic and other adverse effects.
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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