Warfarin with Anistreplase Interaction Details
Brand Names Associated with Warfarin
- Coumadin®
- Jantoven®
- Warfarin
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Nov 07, 2023
Interaction Effect
An increased risk of bleeding
Interaction Summary
Concomitant use of an anticoagulant with a fibrinolytic (eg, thrombolytic) agent may increase the risk of major bleeding events due to additive effects. Two studies have demonstrated safe coadministration of low-dose or low-intensity warfarin therapy (ie, INR of 1.7 or less) with a thrombolytic agent . However, if concomitant use of an anticoagulant with a fibrinolytic agent is required, patients should be monitored clinically for signs and symptoms of external or internal bleeding. Laboratory monitoring is also advised . Closely observe surgical wound drainage. If Hb levels fall, or if there is a decrease in blood pressure, bleeding should be suspected .
Severity
Major
Onset
Unspecified
Evidence
Theoretical
How To Manage Interaction
Concomitant use of an anticoagulant with a fibrinolytic (eg, thrombolytic) agent may increase the risk of major bleeding events. If concomitant use of an anticoagulant and a fibrinolytic agent is required, observe patients for external bleeding and be alert for signs and symptoms of internal bleeding. Close clinical and laboratory monitoring, including appropriate anticoagulation tests and prothrombin times, is advised . Closely observe surgical wound drainage and periodically measure Hb levels. If Hb levels fall, or if there is a decrease in blood pressure, bleeding should be suspected .
Mechanism Of Interaction
Additive effects
Literature Reports
A) In clinical trials in patients undergoing percutaneous transluminal coronary angioplasty (PTCA) or percutaneous coronary intervention (PCI), coadministration of bivalirudin with thrombolytic agents, glycoprotein IIb/IIIa inhibitors, warfarin, or heparin was associated with increased risks of major bleeding events when compared with patients not receiving these concomitant medications . Any agent that may enhance the risk of hemorrhage should be discontinued prior to initiation of desirudin therapy .
B) Although lower doses were used during streptokinase infusion, warfarin administration did not present any problems, according to a Finnish study that evaluated the use of streptokinase with oral anticoagulants in the treatment of DVT. Forty-four patients initially received warfarin 0.5 mg and streptokinase 600,000 international units. Streptokinase 600,000 international units/hour was continued for 3 days and phlebography was performed to evaluate clearing of the thrombotic occlusion. Treatment was continued for a further 3 days if lysis was incomplete. When necessary, warfarin was given to keep the protein phosphatase (PP) activity level 0.1 to 0.2. Hemorrhage was the reason for the discontinuation of treatment in 8 of the 44 patients (18.2%). Although this study documents concomitant use of oral anticoagulants and streptokinase, both the anticoagulant and streptokinase were initiated at the same time. Since 3 to 5 days is required before hypoprothrombinemia is obtained, these patients did not experience the true interaction of the thrombolytic effect of streptokinase resulting in hypoprothrombinemia due to the concomitant use of warfarin .
C) In a study analyzing registry data of 45,074 patients who received IV tissue plasminogen activator for acute ischemic stroke, there was no significant increase in the risk for symptomatic intracerebral hemorrhage or death in patients on warfarin therapy with an INR of 1.7 or less (n=768) compared with patients not treated with warfarin (n=43,651) after adjusting for age, stroke severity, and comorbidities .
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.
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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.