Drug interactions
Pimavanserin + Ritonavir
Severity: Major
Pimavanserin 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 is a strong CYP3A4 inhibitor and increases pimavanserin exposure, which may increase QT prolongation and other adverse effects.
What this interaction means in plain words
Pimavanserin 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.
Pimavanserin belongs to Central Nervous System; Ritonavir belongs to Anti Virals.
Why it happens
Strong CYP3A4 inhibition reduces pimavanserin clearance.
What to do
Reduce pimavanserin to 10 mg daily during coadministration, per labeling. Monitor ECG and adverse effects.
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 Pimavanserin 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 Pimavanserin
- Lefamulin + Pimavanserin Contraindicated
- Pimavanserin + Pimozide Contraindicated
- Pimavanserin + Vandetanib Contraindicated
- Adagrasib + Pimavanserin Major
- Amiodarone + Pimavanserin Major
- Amisulpride + Pimavanserin 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 Pimavanserin with Ritonavir?
MediHelp rates the interaction as major. Pimavanserin 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 is a strong CYP3A4 inhibitor and increases pimavanserin exposure, which may increase QT prolongation and other adverse effects.
How serious is the interaction between Pimavanserin 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: Reduce pimavanserin to 10 mg daily during coadministration, per labeling. Monitor ECG and adverse effects.
What other medicines interact with Pimavanserin?
MediHelp also lists interactions of Pimavanserin with, for example, Lefamulin, Pimozide, Vandetanib. The full list is on the Pimavanserin 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.
