Drug interactions
Testosterone + Warfarin
Severity: Major
Testosterone and Warfarin: 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
Testosterone and other androgens can strengthen the anticoagulant effect of warfarin, causing a raised INR and an increased risk of bleeding. The effect may emerge soon after starting or increasing androgen therapy.
What this interaction means in plain words
Testosterone and Warfarin 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.
Testosterone belongs to Endocrine; Warfarin belongs to Cardiovascular.
Why it happens
Probably reduced clotting factor synthesis or catabolism alteration and possibly reduced warfarin clearance; the mechanism is not fully established.
What to do
Check INR more often when testosterone is started, adjusted or stopped, and reduce the warfarin dose as indicated. Educate the patient about signs of bleeding.
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 Warfarin
- Defibrotide + Warfarin Contraindicated
- Ketorolac + Warfarin Contraindicated
- Abciximab + Warfarin Major
- Acetylsalicylic acid + Warfarin Major
- Adagrasib + Warfarin Major
- Amiodarone + Warfarin Major
Other interactions of Testosterone
- Androstenedione + Testosterone Moderate
- Betamethasone + Testosterone Moderate
- Carbamazepine + Testosterone Moderate
- Corticotropin + Testosterone Moderate
- Cortisone + Testosterone Moderate
- Cyclosporine + Testosterone Moderate
Frequently asked questions
Can I take Testosterone with Warfarin?
MediHelp rates the interaction as major. Testosterone and Warfarin 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. Testosterone and other androgens can strengthen the anticoagulant effect of warfarin, causing a raised INR and an increased risk of bleeding. The effect may emerge soon after starting or increasing androgen therapy.
How serious is the interaction between Testosterone and Warfarin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check INR more often when testosterone is started, adjusted or stopped, and reduce the warfarin dose as indicated. Educate the patient about signs of bleeding.
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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