Drug interactions
Pacritinib + Quinidine
Severity: Major
Pacritinib and Quinidine: 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
Pacritinib is a CYP3A4 inhibitor, and quinidine is a CYP3A4 substrate with a narrow therapeutic index. Higher quinidine levels may prolong the QT interval and cause arrhythmia. Pacritinib itself also carries QT risk.
What this interaction means in plain words
Pacritinib and Quinidine 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.
Pacritinib belongs to Oncology; Quinidine belongs to Anti Parasitic.
Why it happens
Pacritinib inhibits CYP3A4, reducing quinidine metabolism, and both drugs have additive QT-prolonging potential.
What to do
Avoid the combination if possible. If it is used, monitor ECG and quinidine concentrations and reduce the quinidine dose as needed.
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 Pacritinib and Quinidine, 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 Quinidine
- Adagrasib + Quinidine Contraindicated
- Arsenic trioxide + Quinidine Contraindicated
- Artemether / lumefantrine + Quinidine Contraindicated
- Chloroquine + Quinidine Contraindicated
- Dofetilide + Quinidine Contraindicated
- Dronedarone + Quinidine Contraindicated
Other interactions of Pacritinib
- Clarithromycin + Pacritinib Contraindicated
- Ketoconazole + Pacritinib Contraindicated
- Pacritinib + Posaconazole Contraindicated
- Pacritinib + Voriconazole Contraindicated
- Amiodarone + Pacritinib Major
- Carbamazepine + Pacritinib Major
Frequently asked questions
Can I take Pacritinib with Quinidine?
MediHelp rates the interaction as major. Pacritinib and Quinidine 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. Pacritinib is a CYP3A4 inhibitor, and quinidine is a CYP3A4 substrate with a narrow therapeutic index. Higher quinidine levels may prolong the QT interval and cause arrhythmia. Pacritinib itself also carries QT risk.
How serious is the interaction between Pacritinib and Quinidine?
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 the combination if possible. If it is used, monitor ECG and quinidine concentrations and reduce the quinidine dose as needed.
What other medicines interact with Quinidine?
MediHelp also lists interactions of Quinidine with, for example, Adagrasib, Arsenic trioxide, Artemether / lumefantrine. The full list is on the Quinidine 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.
