Drug interactions
Bosentan + Ritonavir
Severity: Major
Bosentan and Ritonavir: major interaction.
Last updated Sources: US FDA label
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 inhibits CYP3A4 and markedly raises bosentan concentrations, increasing the risk of hepatotoxicity, hypotension and edema. Bosentan may also modestly lower ritonavir exposure through induction.
What this interaction means in plain words
Bosentan 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.
Bosentan belongs to Miscellaneous; Ritonavir belongs to Anti Virals.
Why it happens
Ritonavir inhibits CYP3A4 and OATP-mediated uptake, reducing bosentan clearance, while bosentan weakly induces CYP3A4.
What to do
In patients already on ritonavir, start bosentan at 62.5 mg once daily or every other day. If starting ritonavir in a patient on bosentan, hold bosentan for at least 36 hours first and restart after about 10 days at the reduced dose, monitoring liver tests and HIV viral load.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Bosentan 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 7 days on the web. No card needed.
References
Other interactions of Bosentan
- Bosentan + Cyclosporin Contraindicated
- Bosentan + Glibenclamide Contraindicated
- Bosentan + Glyburide-metformin Contraindicated
- Bosentan + Lonafarnib Contraindicated
- Bosentan + Sparsentan Contraindicated
- Artemether / lumefantrine + Bosentan Major
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 Bosentan with Ritonavir?
MediHelp rates the interaction as major. Bosentan 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. Ritonavir inhibits CYP3A4 and markedly raises bosentan concentrations, increasing the risk of hepatotoxicity, hypotension and edema. Bosentan may also modestly lower ritonavir exposure through induction.
How serious is the interaction between Bosentan 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: In patients already on ritonavir, start bosentan at 62.5 mg once daily or every other day. If starting ritonavir in a patient on bosentan, hold bosentan for at least 36 hours first and restart after about 10 days at the reduced dose, monitoring liver tests and HIV viral load.
What other medicines interact with Bosentan?
MediHelp also lists interactions of Bosentan with, for example, Cyclosporin, Glibenclamide, Glyburide-metformin. The full list is on the Bosentan 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.
