Drug interactions
Levonorgestrel transdermal + Warfarin
Severity: Minor
Levonorgestrel transdermal and Warfarin: minor 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
Hormonal progestins have been associated with isolated changes in INR in patients on warfarin. The effect is generally small and unpredictable.
What this interaction means in plain words
Levonorgestrel transdermal and Warfarin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
The mechanism is not established; minimal systemic effect on warfarin pharmacokinetics is expected.
What to do
Check INR after starting or stopping the patch and adjust the warfarin dose only if the INR changes.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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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
Frequently asked questions
Can I take Levonorgestrel transdermal with Warfarin?
MediHelp rates the interaction as minor. Levonorgestrel transdermal and Warfarin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Hormonal progestins have been associated with isolated changes in INR in patients on warfarin. The effect is generally small and unpredictable.
How serious is the interaction between Levonorgestrel transdermal and Warfarin?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check INR after starting or stopping the patch and adjust the warfarin dose only if the INR changes.
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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