Drug interactions
Clotrimazole + Warfarin
Severity: Moderate
Clotrimazole and Warfarin: moderate 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
Clotrimazole may increase warfarin exposure and INR, raising bleeding risk. The risk depends on the route. It is most relevant with oral troches/lozenges and intravaginal products, where some systemic absorption occurs. Elevated INR with vaginal azole use has been reported. Cutaneous topical use carries minimal expected risk because systemic absorption is negligible.
What this interaction means in plain words
Clotrimazole 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.
Clotrimazole belongs to Anti Fungals; Warfarin belongs to Cardiovascular.
Why it happens
Pharmacokinetic. Clotrimazole is an azole that inhibits CYP3A4 (and CYP2C9 in vitro). This may reduce metabolism of warfarin enantiomers, particularly the CYP3A4-mediated clearance of R-warfarin, and increase anticoagulant effect.
What to do
Monitor INR more closely, for example within 3–7 days, when starting or stopping clotrimazole troches or vaginal preparations in patients on warfarin. Adjust the warfarin dose as 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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References
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 Clotrimazole
- Clotrimazole + Lomitapide Major
- Clotrimazole + Mavacamten Major
- Clotrimazole + Mobocertinib Major
- Clotrimazole + Voclosporin Major
- Bosutinib + Clotrimazole Moderate
- Cannabidiol + Clotrimazole Moderate
Frequently asked questions
Can I take Clotrimazole with Warfarin?
MediHelp rates the interaction as moderate. Clotrimazole 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. Clotrimazole may increase warfarin exposure and INR, raising bleeding risk. The risk depends on the route. It is most relevant with oral troches/lozenges and intravaginal products, where some systemic absorption occurs. Elevated INR with vaginal azole use has been reported. Cutaneous topical use carries minimal expected risk because systemic absorption is negligible.
How serious is the interaction between Clotrimazole 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 closely, for example within 3–7 days, when starting or stopping clotrimazole troches or vaginal preparations in patients on warfarin. Adjust the warfarin dose as needed.
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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