Drug interactions
Rifaximin + Ritonavir
Severity: Moderate
Rifaximin 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 is a potent P-glycoprotein inhibitor and can increase systemic rifaximin concentrations. Rifaximin is usually barely absorbed, but exposure may rise meaningfully, especially in patients with hepatic impairment.
What this interaction means in plain words
Rifaximin 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.
Rifaximin belongs to Anti Bacterial; Ritonavir belongs to Anti Virals.
Why it happens
Ritonavir inhibits P-glycoprotein, reducing efflux of rifaximin and increasing absorption.
What to do
Use only if the benefit justifies the risk, particularly in Child-Pugh B or C disease. Monitor for rifaximin adverse effects.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Rifaximin and Ritonavir, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
Other interactions of Rifaximin
- Cholera vaccine + Rifaximin Major
- Microbiota + Rifaximin Major
- Amiodarone + Rifaximin Moderate
- Bcg intravesical live + Rifaximin Moderate
- Cyclosporine + Rifaximin Moderate
- Cyclosporin + Rifaximin Moderate
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 Rifaximin with Ritonavir?
MediHelp rates the interaction as moderate. Rifaximin 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 is a potent P-glycoprotein inhibitor and can increase systemic rifaximin concentrations. Rifaximin is usually barely absorbed, but exposure may rise meaningfully, especially in patients with hepatic impairment.
How serious is the interaction between Rifaximin 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 if the benefit justifies the risk, particularly in Child-Pugh B or C disease. Monitor for rifaximin adverse effects.
What other medicines interact with Rifaximin?
MediHelp also lists interactions of Rifaximin with, for example, Cholera vaccine, Microbiota, Amiodarone. The full list is on the Rifaximin page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
