Drug interactions
Piperacillin + Warfarin
Severity: Moderate
Piperacillin and Warfarin: moderate 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
Piperacillin can impair platelet function and may increase bleeding tendency, and infection or antibiotic effects on gut flora may also raise INR in warfarin-treated patients. Bleeding risk is therefore increased, particularly at high doses or with renal impairment.
What this interaction means in plain words
Piperacillin and Warfarin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Piperacillin belongs to Anti Bacterial; Warfarin belongs to Cardiovascular.
Why it happens
Additive pharmacodynamic effect: penicillin-induced platelet dysfunction on top of anticoagulation, with possible INR elevation.
What to do
Monitor INR more frequently during and after piperacillin therapy and adjust warfarin dose as needed; watch for signs of bleeding.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Piperacillin
- Piperacillin + Vancomycin Major
- Acetylsalicylic acid + Piperacillin Moderate
- Amikacin + Piperacillin Moderate
- Antithrombin alfa + Piperacillin Moderate
- Antithrombin iii + Piperacillin Moderate
- Argatroban + Piperacillin Moderate
Other interactions of Warfarin
- Defibrotide + Warfarin Contraindicated
- Ketorolac + Warfarin Contraindicated
- Abciximab + Warfarin Major
- Acetylsalicylic acid + Warfarin Major
- Adagrasib + Warfarin Major
- Amiodarone + Warfarin Major
Frequently asked questions
Can I take Piperacillin with Warfarin?
MediHelp rates the interaction as moderate. Piperacillin and Warfarin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Piperacillin can impair platelet function and may increase bleeding tendency, and infection or antibiotic effects on gut flora may also raise INR in warfarin-treated patients. Bleeding risk is therefore increased, particularly at high doses or with renal impairment.
How serious is the interaction between Piperacillin and Warfarin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor INR more frequently during and after piperacillin therapy and adjust warfarin dose as needed; watch for signs of bleeding.
What other medicines interact with Piperacillin?
MediHelp also lists interactions of Piperacillin with, for example, Vancomycin, Acetylsalicylic acid, Amikacin. The full list is on the Piperacillin page.
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