Fentanyl and Ritonavir: Drug Interaction Guide
Quick answer: This is a major interaction — avoid combining Fentanyl and Ritonavir unless specifically directed by your doctor.
How Fentanyl interacts with Ritonavir
Ritonavir is a potent CYP3A4 inhibitor that markedly reduces fentanyl clearance, raising plasma levels and risking respiratory depression, sedation, and death.
What you should do
Avoid co-administration where possible. If fentanyl is needed, reduce dose substantially, use shortest duration, and monitor respiratory rate and oxygenation continuously.
Key facts
Severity
Major — avoid combination
Mechanism
Ritonavir is a potent CYP3A4 inhibitor that markedly reduces fentanyl clearance, raising plasma levels and risking respi...
Action
Avoid co-administration where possible. If fentanyl is needed, reduce dose substantially, use shortest duration, and mon...
Frequently asked questions
Can I take Fentanyl and Ritonavir together?
No — this combination should generally be avoided. Avoid co-administration where possible. If fentanyl is needed, reduce dose substantially, use shortest duration, and monitor respiratory rate and oxygenation continuously.
What is the severity of this interaction?
The interaction between Fentanyl and Ritonavir is classified as Major — avoid combination. Ritonavir is a potent CYP3A4 inhibitor that markedly reduces fentanyl clearance, raising plasma levels and risking respiratory depression, sedation, and death.
What should I do if I'm prescribed both?
Avoid co-administration where possible. If fentanyl is needed, reduce dose substantially, use shortest duration, and monitor respiratory rate and oxygenation continuously. Always consult your prescribing clinician — do not stop or change medications without medical guidance.
Last reviewed: by iMedic Medical Editorial Team. Our editorial process.