Drug interactions
Ketoconazole + Nelfinavir
Severity: Moderate
Ketoconazole and Nelfinavir: 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 increases nelfinavir exposure, which may heighten adverse effects such as diarrhea. The increase is generally modest and manageable.
What this interaction means in plain words
Ketoconazole and Nelfinavir 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 belongs to Anti Fungals; Nelfinavir belongs to Anti Virals.
Why it happens
Ketoconazole inhibits CYP3A4 and P-glycoprotein, reducing nelfinavir clearance.
What to do
No routine dose adjustment is recommended; monitor for nelfinavir adverse effects and liver enzymes.
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
Other interactions of Nelfinavir
- Alfuzosin + Nelfinavir Contraindicated
- Avanafil + Nelfinavir Contraindicated
- Dronedarone + Nelfinavir Contraindicated
- Eletriptan + Nelfinavir Contraindicated
- Ergotamine + Nelfinavir Contraindicated
- Flibanserin + Nelfinavir Contraindicated
Frequently asked questions
Can I take Ketoconazole with Nelfinavir?
MediHelp rates the interaction as moderate. Ketoconazole and Nelfinavir 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 increases nelfinavir exposure, which may heighten adverse effects such as diarrhea. The increase is generally modest and manageable.
How serious is the interaction between Ketoconazole and Nelfinavir?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No routine dose adjustment is recommended; monitor for nelfinavir adverse effects and liver enzymes.
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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