Drug interactions
Posaconazole + Ritonavir
Severity: Moderate
Posaconazole and Ritonavir: 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
Posaconazole can raise ritonavir concentrations, while ritonavir may modestly affect posaconazole exposure. Ritonavir at antiretroviral doses is a strong CYP3A4 inhibitor, so concurrent drugs also need review.
What this interaction means in plain words
Posaconazole and Ritonavir 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.
Posaconazole belongs to Anti Fungals; Ritonavir belongs to Anti Virals.
Why it happens
Posaconazole inhibits CYP3A4 metabolism of ritonavir, and ritonavir may alter posaconazole disposition via P-glycoprotein and CYP3A4.
What to do
Monitor for ritonavir adverse effects such as gastrointestinal upset and liver enzyme elevations, and monitor antifungal response, with posaconazole levels if 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 Posaconazole
- Artemether + Posaconazole Contraindicated
- Avanafil + Posaconazole Contraindicated
- Cobimetinib + Posaconazole Contraindicated
- Conivaptan + Posaconazole Contraindicated
- Dihydroergotamine intranasal + Posaconazole Contraindicated
- Dihydroergotamine + Posaconazole Contraindicated
Other interactions of Ritonavir
- Alfuzosin + Ritonavir Contraindicated
- Amiodarone + Ritonavir Contraindicated
- Avanafil + Ritonavir Contraindicated
- Colchicine + Ritonavir Contraindicated
- Dronedarone + Ritonavir Contraindicated
- Eletriptan + Ritonavir Contraindicated
Frequently asked questions
Can I take Posaconazole with Ritonavir?
MediHelp rates the interaction as moderate. Posaconazole and Ritonavir 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. Posaconazole can raise ritonavir concentrations, while ritonavir may modestly affect posaconazole exposure. Ritonavir at antiretroviral doses is a strong CYP3A4 inhibitor, so concurrent drugs also need review.
How serious is the interaction between Posaconazole and Ritonavir?
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 ritonavir adverse effects such as gastrointestinal upset and liver enzyme elevations, and monitor antifungal response, with posaconazole levels if needed.
What other medicines interact with Posaconazole?
MediHelp also lists interactions of Posaconazole with, for example, Artemether, Avanafil, Cobimetinib. The full list is on the Posaconazole page.
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