Drug interactions
Griseofulvin + Warfarin
Severity: Moderate
Griseofulvin 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
Griseofulvin can reduce the anticoagulant effect of warfarin, with a fall in INR reported. This risks thromboembolism, and the effect may persist after griseofulvin is stopped.
What this interaction means in plain words
Griseofulvin 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.
Griseofulvin belongs to Anti Fungals; Warfarin belongs to Cardiovascular.
Why it happens
Griseofulvin induces hepatic enzymes that metabolize warfarin, increasing its clearance.
What to do
Check INR within a few days of starting griseofulvin and adjust the warfarin dose. Recheck INR after griseofulvin is stopped to avoid over-anticoagulation.
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 Griseofulvin
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 Griseofulvin with Warfarin?
MediHelp rates the interaction as moderate. Griseofulvin 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. Griseofulvin can reduce the anticoagulant effect of warfarin, with a fall in INR reported. This risks thromboembolism, and the effect may persist after griseofulvin is stopped.
How serious is the interaction between Griseofulvin 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: Check INR within a few days of starting griseofulvin and adjust the warfarin dose. Recheck INR after griseofulvin is stopped to avoid over-anticoagulation.
What other medicines interact with Griseofulvin?
MediHelp also lists interactions of Griseofulvin with, for example, Cyclosporine, Cyclosporin, Desogestrel-ethinyl estradiol. The full list is on the Griseofulvin page.
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