Drug interactions
Nirmatrelvir / ritonavir + Ranolazine
Severity: Contraindicated
Nirmatrelvir / ritonavir and Ranolazine: contraindicated 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 strongly inhibits CYP3A4 and substantially raises ranolazine concentrations, increasing QT prolongation and dose-related toxicity. Strong CYP3A inhibitors are contraindicated with ranolazine.
What this interaction means in plain words
Nirmatrelvir / ritonavir and Ranolazine are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Why it happens
Potent CYP3A4 inhibition by ritonavir reduces ranolazine metabolism.
What to do
Do not co-administer. Use an alternative COVID-19 treatment or temporarily hold ranolazine according to current guidance.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Nirmatrelvir / ritonavir and Ranolazine, 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 Ranolazine
- Adagrasib + Ranolazine Contraindicated
- Amobarbital + Ranolazine Contraindicated
- Apalutamide + Ranolazine Contraindicated
- Butabarbital + Ranolazine Contraindicated
- Carbamazepine + Ranolazine Contraindicated
- Clarithromycin + Ranolazine Contraindicated
Frequently asked questions
Can I take Nirmatrelvir / ritonavir with Ranolazine?
MediHelp rates the interaction as contraindicated. Nirmatrelvir / ritonavir and Ranolazine are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Ritonavir strongly inhibits CYP3A4 and substantially raises ranolazine concentrations, increasing QT prolongation and dose-related toxicity. Strong CYP3A inhibitors are contraindicated with ranolazine.
How serious is the interaction between Nirmatrelvir / ritonavir and Ranolazine?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Do not co-administer. Use an alternative COVID-19 treatment or temporarily hold ranolazine according to current guidance.
What other medicines interact with Ranolazine?
MediHelp also lists interactions of Ranolazine with, for example, Adagrasib, Amobarbital, Apalutamide. The full list is on the Ranolazine 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.
