Warfarin with Testosterone Interaction Details
Brand Names Associated with Warfarin
- Coumadin®
- Jantoven®
- Warfarin
Brand Names Associated with Testosterone
- Jatenzo®
- Testosterone
- testosterone undecanoate
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Nov 27, 2023
Interaction Effect
An increased risk of bleeding
Interaction Summary
Concomitant use of testosterone and warfarin may result in an increased risk of bleeding. A number of case reports have demonstrated prolonged prothrombin time and hemorrhages with coadministration of oral anticoagulants and 17-alkylated androgens. Testosterone has been reported to suppress the clotting factors II, V, VII, and X, which may lead to bleeding in patients on concomitant anticoagulant therapy . If coadministration of testosterone and warfarin is deemed necessary, make INR determinations and increase prothrombin time monitoring, particularly when treatment with testosterone is initiated or discontinued .
Severity
Major
Onset
Delayed
Evidence
Probable
How To Manage Interaction
If the concomitant use of oral anticoagulants and testosterone is required, make INR determinations and increase monitoring of prothrombin time, particularly at androgen treatment initiation and discontinuation.
Mechanism Of Interaction
Modification of coagulation factor, hepatic synthesis, and competitive inhibition of plasma protein binding by testosterone
Literature Reports
A) Anabolic steroids have been well documented to cause important interactions with dicumarol, another anticoagulant. Anabolic steroids enhance the anticoagulant activity of dicumarol perhaps through reductions in clotting factor formation and increased clotting factor degradation. The 17-alpha-alkylated steroids (fluoxymesterone, oxandrolone, oxymetholone, methyltestosterone, methandrostenolone, stanozolol) appear to be more likely to induce this reaction than the non-substituted steroids .
B) Significant enhancement of the anticoagulant effects of warfarin was described in a 69-year-old woman following application of a vaginal ointment of testosterone propionate . The mechanism of interaction is unclear.
Warfarin Overview
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Warfarin is used to prevent blood clots from forming or growing larger in your blood and blood vessels. It is prescribed for people with certain types of irregular heartbeat, people with prosthetic (replacement or mechanical) heart valves, and people who have suffered a heart attack. Warfarin is also used to treat or prevent venous thrombosis (swelling and blood clot in a vein) and pulmonary embolism (a blood clot in the lung). Warfarin is in a class of medications called anticoagulants ('blood thinners'). It works by decreasing the clotting ability of the blood.
Testosterone Overview
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Testosterone is used to treat symptoms of low testosterone in men who have hypogonadism (a condition in which the body does not produce enough natural testosterone). Testosterone is used only for men with low testosterone levels caused by certain medical conditions, including disorders of the testicles, pituitary gland, (a small gland in the brain), or hypothalamus (a part of the brain) that cause hypogonadism. Your doctor will order certain lab tests to check your testosterone levels to see if they are low before you begin to take testosterone. Testosterone should not be used treat the symptoms of low testosterone in men who have low testosterone due to aging ('age-related hypogonadism'). Testosterone is a hormone produced by the body that contributes to the growth, development, and functioning of the male sexual organs and typical male characteristics. Testosterone works by replacing testosterone that is normally produced by the body.
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Definitions
Severity Categories
Contraindicated
These drugs, generally, should not be used together simultaneously due to the high risk of severe adverse effects. Combining these medications can lead to dangerous health outcomes and should be strictly avoided unless otherwise instructed by your provider.
Major
This interaction could result in very serious and potentially life-threatening consequences. If you are taking this drug combination, it is very important to be under close medical supervision to minimize severe side effects and ensure your safety. It may be necessary to change a medication or dosage to prevent harm.
Moderate
This interaction has the potential to worsen your medical condition or alter the effectiveness of your treatment. It's important that you are monitored closely and you potentially may need to make adjustments in your treatment plan or drug dosage to maintain optimal health.
Minor
While this interaction is unlikely to cause significant problems, it could intensify side effects or reduce the effectiveness of one or both medications. Monitoring for changes in symptoms and your condition is recommended, and adjustments may be made if needed to manage any increased or more pronounced side effects.
Onset
Rapid: Onset of drug interaction typically occurs within 24 hours of co-administration.
Delayed: Onset of drug interaction typically occurs more than 24 hours after co-administration.
Evidence
Level of documentation of the interaction.
Established: The interaction is documented and substantiated in peer-reviewed medical literature.
Theoretical: This interaction is not fully supported by current medical evidence or well-documented sources, but it is based on known drug mechanisms, drug effects, and other relevant information.
How To Manage The Interaction
Provides a detailed discussion on how patients and clinicians can approach the identified drug interaction as well as offers guidance on what to expect and strategies to potentially mitigate the effects of the interaction. This may include recommendations on adjusting medication dosages, altering the timing of drug administration, or closely monitoring for specific symptoms.
It's important to note that all medical situations are unique, and management approaches should be tailored to individual circumstances. Patients should always consult their healthcare provider for personalized advice and guidance on managing drug interactions effectively.
Mechanism Of Interaction
The theorized or clinically determined reason (i.e., mechanism) why the drug-drug interaction occurs.
Disclaimer: The information provided on this page is for informational purposes only and should not be considered medical advice. Always consult with a qualified healthcare professional regarding your specific circumstances and medical conditions.
Where Does Our Information Come From?
Information for our drug interactions is compiled from several drug compendia, including:
The prescribing information for each drug, as published on DailyMED, is also used.
Individual drug-drug interaction detail pages contain references specific to that interaction. You can click on the reference number within brackets '[]' to see what reference was utilized.
The information posted is fact-checked by HelloPharmacist clinicians and reviewed quarterly.