Drug interactions
Rifampicin + Ritonavir
Severity: Major
Rifampicin and Ritonavir: 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
Rifampicin strongly induces CYP3A4 and P-gp, lowering ritonavir and coadministered protease inhibitor concentrations, risking virologic failure. With saquinavir/ritonavir the combination has caused severe hepatotoxicity.
What this interaction means in plain words
Rifampicin and Ritonavir 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.
Rifampicin belongs to Anti Bacterial; Ritonavir belongs to Anti Virals.
Why it happens
Enzyme induction by rifampicin accelerates protease inhibitor metabolism, with additive hepatotoxic potential.
What to do
Avoid rifampicin with saquinavir/ritonavir. With other ritonavir-boosted regimens use only per specific guidance, with liver enzyme monitoring, or substitute rifabutin.
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 Ritonavir
- Alfuzosin + Ritonavir Contraindicated
- Amiodarone + Ritonavir Contraindicated
- Avanafil + Ritonavir Contraindicated
- Colchicine + Ritonavir Contraindicated
- Dronedarone + Ritonavir Contraindicated
- Eletriptan + Ritonavir Contraindicated
Other interactions of Rifampicin
- Cabotegravir + Rifampicin Contraindicated
- Delamanid + Rifampicin Contraindicated
- Doravirine + Rifampicin Contraindicated
- Ensitrelvir + Rifampicin Contraindicated
- Fostemsavir + Rifampicin Contraindicated
- Isavuconazole + Rifampicin Contraindicated
Frequently asked questions
Can I take Rifampicin with Ritonavir?
MediHelp rates the interaction as major. Rifampicin and Ritonavir 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. Rifampicin strongly induces CYP3A4 and P-gp, lowering ritonavir and coadministered protease inhibitor concentrations, risking virologic failure. With saquinavir/ritonavir the combination has caused severe hepatotoxicity.
How serious is the interaction between Rifampicin and Ritonavir?
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 rifampicin with saquinavir/ritonavir. With other ritonavir-boosted regimens use only per specific guidance, with liver enzyme monitoring, or substitute rifabutin.
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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