Drug interactions
Nelfinavir + Warfarin
Severity: Moderate
Nelfinavir 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
Nelfinavir inhibits CYP3A4 and may raise R-warfarin levels, but it can also induce other enzymes, so the INR may move in either direction. This unpredictability makes anticoagulation control harder.
What this interaction means in plain words
Nelfinavir 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.
Nelfinavir belongs to Anti Virals; Warfarin belongs to Cardiovascular.
Why it happens
Mixed inhibition of CYP3A4 and induction of other metabolic pathways alters warfarin clearance.
What to do
Monitor INR closely when nelfinavir is started or stopped and adjust the warfarin dose based on results.
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 Warfarin
- Defibrotide + Warfarin Contraindicated
- Ketorolac + Warfarin Contraindicated
- Abciximab + Warfarin Major
- Acetylsalicylic acid + Warfarin Major
- Adagrasib + Warfarin Major
- Amiodarone + Warfarin Major
Other interactions of Nelfinavir
- Alfuzosin + Nelfinavir Contraindicated
- Avanafil + Nelfinavir Contraindicated
- Dronedarone + Nelfinavir Contraindicated
- Eletriptan + Nelfinavir Contraindicated
- Ergotamine + Nelfinavir Contraindicated
- Flibanserin + Nelfinavir Contraindicated
Frequently asked questions
Can I take Nelfinavir with Warfarin?
MediHelp rates the interaction as moderate. Nelfinavir 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. Nelfinavir inhibits CYP3A4 and may raise R-warfarin levels, but it can also induce other enzymes, so the INR may move in either direction. This unpredictability makes anticoagulation control harder.
How serious is the interaction between Nelfinavir 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 closely when nelfinavir is started or stopped and adjust the warfarin dose based on results.
What other medicines interact with Warfarin?
MediHelp also lists interactions of Warfarin with, for example, Defibrotide, Ketorolac, Abciximab. The full list is on the Warfarin page.
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