Warfarin with Prednisolone Interaction Details
Brand Names Associated with Warfarin
- Coumadin®
- Jantoven®
- Warfarin
Brand Names Associated with Prednisolone
- Flo-Pred®
- Orapred®
- Pediapred®
- Prednisolone
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Nov 07, 2023
Interaction Effect
Increased risk of bleeding or diminished effects of warfarin
Interaction Summary
Concomitant use of warfarin and an adrenocortical steroid, such as prednisoLONE, has been associated with increased and decreased prothrombin time/INR responses. Monitor prothrombin time/INR closely if prednisoLONE and warfarin are taken concomitantly, especially during medication initiation or discontinuation.
Severity
Moderate
Onset
Delayed
Evidence
Theoretical
How To Manage Interaction
Prothrombin time/INR should be monitored closely if prednisoLONE and warfarin are taken concomitantly, especially during medication initiation or discontinuation. Increased and decreased prothrombin time/INR responses have been reported with concomitant use of warfarin and adrenocortical steroids.
Mechanism Of Interaction
Unknown
Literature Reports
A) The interaction of warfarin and CYP2C9 polymorphism and concurrent corticosteroids was evaluated in a study (n=29) in children (mean age 7.3 years) with newly diagnosed cancer. Children received warfarin 0.1 mg/kg/day with a target INR of 1.3 to 1.9 for a treatment period of 6 months. Children were genotyped for CYP2C9*2 and CYP2C9*3 polymorphisms at baseline. Children receiving intermittent steroids (n=15; 14 with acute lymphoblastic leukemia) had significantly lower warfarin requirements (mean dose of 0.057 mg/kg/day (SD=0.03)) during periods on high-dose steroids (prednisone 60 mg/m(2)/day for 11 weeks) compared to periods without steroids (mean dose of 0.12 mg/kg/day (SD=0.04); p less than 0.001). In children with heterozygous polymorphisms (n=8), the number of days to achieve the target INR was significantly lower (3.7 days vs 7 days; p=0.03) than children without mutations (n=21), and a heterozygous genotype was associated with more frequent INR levels above target (p=0.033) .
B) In a retrospective review of 32 patient encounters, patients on long-term warfarin therapy had higher INR values following concurrent corticosteroid therapy compared to INR values prior to corticosteroid initiation. Patients on stable anticoagulation therapy with short term corticosteroid therapy were evaluated with INR measurements obtained 30 days prior to corticosteroid initiation (pre-INR) and during corticosteroid therapy or within 14 days of discontinuation (post-INR). Patients were given corticosteroids for an average of 9 days (6 to 30 days) with prednisone (50%) and methylprednisolone (50%) accounting for the oral corticosteroids the patients were administered. The mean pre-INR value was 2.33 +/- 0.37 (measured 11.9 +/- 7.1 days after corticosteroid initiation) compared to the mean post-INR value of 3.57 +/- 1.07 (measured 6.7 +/- 3.3 days after first dose of corticosteroid) (p less than 0.001). Post-INR measurements above the desired INR goal range were noted in 62.5% of patient encounters, and dose reductions/modifications were required in 50% (n=16) of patient encounters. One adverse event of mild epistaxis was reported. The authors propose that this drug interaction is due to altered liver metabolism of warfarin by corticosteroids .
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.
Prednisolone Overview
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Prednisolone is used alone or with other medications to treat the symptoms of low corticosteroid levels (lack of certain substances that are usually produced by the body and are needed for normal body functioning). Prednisolone is also used to treat certain conditions that affect the blood, skin, eyes, central nervous system, kidneys, lungs, stomach, and intestines. It is also used to treat allergic reactions; and certain types of arthritis; multiple sclerosis (a disease in which the nerves do not function properly); and to help prevent transplant rejection (attack of the transplanted organ by the body) in certain adults who have received a transplant. Prednisolone is also sometimes used to treat symptoms from certain types of cancer. Prednisolone is in a class of medications called corticosteroids. It works by reducing swelling and redness and by changing the way the immune system works.
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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.