Drug interactions
Atazanavir + Ritonavir
Severity: Moderate
Atazanavir 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
Ritonavir markedly raises atazanavir concentrations. This is used deliberately for boosting, but it can increase atazanavir-related adverse effects such as hyperbilirubinemia and PR prolongation.
What this interaction means in plain words
Atazanavir 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.
Atazanavir belongs to Anti Virals; Ritonavir belongs to Anti Virals.
Why it happens
Ritonavir potently inhibits CYP3A4, reducing atazanavir metabolism.
What to do
Use only the labeled boosting dose of ritonavir, typically 100 mg with atazanavir 300 mg daily. Monitor bilirubin, liver tests and ECG as 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 Ritonavir
- Alfuzosin + Ritonavir Contraindicated
- Amiodarone + Ritonavir Contraindicated
- Avanafil + Ritonavir Contraindicated
- Colchicine + Ritonavir Contraindicated
- Dronedarone + Ritonavir Contraindicated
- Eletriptan + Ritonavir Contraindicated
Other interactions of Atazanavir
- Alfuzosin + Atazanavir Contraindicated
- Atazanavir + Avanafil Contraindicated
- Atazanavir + Dronedarone Contraindicated
- Atazanavir + Eletriptan Contraindicated
- Atazanavir + Eplerenone Contraindicated
- Atazanavir + Ergotamine Contraindicated
Frequently asked questions
Can I take Atazanavir with Ritonavir?
MediHelp rates the interaction as moderate. Atazanavir 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. Ritonavir markedly raises atazanavir concentrations. This is used deliberately for boosting, but it can increase atazanavir-related adverse effects such as hyperbilirubinemia and PR prolongation.
How serious is the interaction between Atazanavir 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: Use only the labeled boosting dose of ritonavir, typically 100 mg with atazanavir 300 mg daily. Monitor bilirubin, liver tests and ECG as needed.
What other medicines interact with Ritonavir?
MediHelp also lists interactions of Ritonavir with, for example, Alfuzosin, Amiodarone, Avanafil. The full list is on the Ritonavir page.
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