Drug interactions
Antithrombin iii + Ethinyl estradiol-levonorgestrel
Severity: Major
Antithrombin iii and Ethinyl estradiol-levonorgestrel: major 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
Estrogen-containing contraceptives raise thrombotic risk and oppose the antithrombotic purpose of antithrombin replacement. This is particularly relevant in hereditary antithrombin deficiency.
What this interaction means in plain words
Antithrombin iii and Ethinyl estradiol-levonorgestrel can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Estrogen increases procoagulant factors and reduces natural anticoagulant activity, opposing antithrombin therapy.
What to do
Avoid estrogen-containing contraceptives in these patients and choose a progestin-only or non-hormonal method. Monitor antithrombin activity.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Ethinyl estradiol-levonorgestrel
- Ethinyl estradiol-levonorgestrel + Fezolinetant Contraindicated
- Ethinyl estradiol-levonorgestrel + Ombitasvir / paritaprevir / ritonavir and dasabuvir Contraindicated
- Ethinyl estradiol-levonorgestrel + Tranexamic acid Contraindicated
- Aminocaproic acid + Ethinyl estradiol-levonorgestrel Major
- Amobarbital + Ethinyl estradiol-levonorgestrel Major
- Anastrozole + Ethinyl estradiol-levonorgestrel Major
Frequently asked questions
Can I take Antithrombin iii with Ethinyl estradiol-levonorgestrel?
MediHelp rates the interaction as major. Antithrombin iii and Ethinyl estradiol-levonorgestrel can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Estrogen-containing contraceptives raise thrombotic risk and oppose the antithrombotic purpose of antithrombin replacement. This is particularly relevant in hereditary antithrombin deficiency.
How serious is the interaction between Antithrombin iii and Ethinyl estradiol-levonorgestrel?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid estrogen-containing contraceptives in these patients and choose a progestin-only or non-hormonal method. Monitor antithrombin activity.
What other medicines interact with Ethinyl estradiol-levonorgestrel?
MediHelp also lists interactions of Ethinyl estradiol-levonorgestrel with, for example, Fezolinetant, Ombitasvir / paritaprevir / ritonavir and dasabuvir, Tranexamic acid. The full list is on the Ethinyl estradiol-levonorgestrel page.
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