Drug interactions
Argatroban + Phenindione
Severity: Major
Argatroban and Phenindione: 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
Both agents lower coagulation, so combining them raises bleeding risk. Argatroban also raises the INR, which complicates monitoring of vitamin K antagonist therapy such as phenindione. This overlap is commonly encountered when transitioning to oral anticoagulation.
What this interaction means in plain words
Argatroban and Phenindione 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.
Why it happens
Additive anticoagulation: direct thrombin inhibition plus vitamin K-dependent clotting factor depletion, with argatroban also falsely elevating INR.
What to do
Overlap only when transitioning, following labeled guidance for INR measurement (for example, using chromogenic factor X or checking INR after a temporary hold of argatroban). Monitor for bleeding.
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?
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References
Other interactions of Argatroban
- Argatroban + Defibrotide Contraindicated
- Argatroban + Ketorolac Contraindicated
- Argatroban + Mifepristone Contraindicated
- Abciximab + Argatroban Major
- Acalabrutinib + Argatroban Major
- Acetylsalicylic acid + Argatroban Major
Frequently asked questions
Can I take Argatroban with Phenindione?
MediHelp rates the interaction as major. Argatroban and Phenindione 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. Both agents lower coagulation, so combining them raises bleeding risk. Argatroban also raises the INR, which complicates monitoring of vitamin K antagonist therapy such as phenindione. This overlap is commonly encountered when transitioning to oral anticoagulation.
How serious is the interaction between Argatroban and Phenindione?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Overlap only when transitioning, following labeled guidance for INR measurement (for example, using chromogenic factor X or checking INR after a temporary hold of argatroban). Monitor for bleeding.
What other medicines interact with Argatroban?
MediHelp also lists interactions of Argatroban with, for example, Defibrotide, Ketorolac, Mifepristone. The full list is on the Argatroban page.
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