Drug interactions
Heparin + Levonorgestrel
Severity: Minor
Heparin and Levonorgestrel: 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 contraceptives containing levonorgestrel are linked to a prothrombotic tendency, mainly when combined with estrogen. Progestin-only levonorgestrel carries a much smaller thrombotic risk, and it does not meaningfully blunt heparin's anticoagulant effect.
What this interaction means in plain words
Heparin and Levonorgestrel have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Heparin belongs to Cardiovascular; Levonorgestrel belongs to Endocrine.
Why it happens
Theoretical pharmacodynamic opposition from hormone-related effects on coagulation factors; not a established direct interaction.
What to do
No change is usually needed; for patients with active thrombosis prefer progestin-only or non-hormonal contraception and review thrombotic risk.
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 Heparin
- Defibrotide + Heparin Contraindicated
- Heparin + Ketorolac Contraindicated
- Heparin + Oritavancin Contraindicated
- Acemetacin + Heparin Major
- Acetylsalicylic acid + Heparin Major
- Alteplase + Heparin Major
Other interactions of Levonorgestrel
Frequently asked questions
Can I take Heparin with Levonorgestrel?
MediHelp rates the interaction as minor. Heparin and Levonorgestrel 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 contraceptives containing levonorgestrel are linked to a prothrombotic tendency, mainly when combined with estrogen. Progestin-only levonorgestrel carries a much smaller thrombotic risk, and it does not meaningfully blunt heparin's anticoagulant effect.
How serious is the interaction between Heparin and Levonorgestrel?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No change is usually needed; for patients with active thrombosis prefer progestin-only or non-hormonal contraception and review thrombotic risk.
What other medicines interact with Heparin?
MediHelp also lists interactions of Heparin with, for example, Defibrotide, Ketorolac, Oritavancin. The full list is on the Heparin page.
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