Drug interactions
Oritavancin + Warfarin
Severity: Moderate
Oritavancin 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
Oritavancin artificially prolongs PT/INR and aPTT in laboratory tests for hours to days after dosing, so coagulation results may not reflect true anticoagulation in warfarin-treated patients. Oritavancin may also modestly raise warfarin exposure, so true bleeding risk may be increased.
What this interaction means in plain words
Oritavancin 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.
Oritavancin belongs to Anti Bacterial; Warfarin belongs to Cardiovascular.
Why it happens
Oritavancin binds and interferes with phospholipid reagents used in clotting assays, and may weakly inhibit CYP2C9 and so reduce warfarin clearance.
What to do
Avoid relying on INR measurements shortly after oritavancin dosing and monitor the patient clinically for bleeding. Consider alternative anticoagulation monitoring or a different antibiotic if tight INR control is needed.
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 Oritavancin
- Heparin + Oritavancin Contraindicated
- Carbamazepine + Oritavancin Minor
- Cyclosporin + Oritavancin Minor
- Ethosuximide + Oritavancin Minor
- Flecainide + Oritavancin Minor
- Oritavancin + Phenytoin Minor
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 Oritavancin with Warfarin?
MediHelp rates the interaction as moderate. Oritavancin 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. Oritavancin artificially prolongs PT/INR and aPTT in laboratory tests for hours to days after dosing, so coagulation results may not reflect true anticoagulation in warfarin-treated patients. Oritavancin may also modestly raise warfarin exposure, so true bleeding risk may be increased.
How serious is the interaction between Oritavancin 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: Avoid relying on INR measurements shortly after oritavancin dosing and monitor the patient clinically for bleeding. Consider alternative anticoagulation monitoring or a different antibiotic if tight INR control is needed.
What other medicines interact with Oritavancin?
MediHelp also lists interactions of Oritavancin with, for example, Heparin, Carbamazepine, Cyclosporin. The full list is on the Oritavancin page.
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