Nortriptyline with Acenocoumarol Interaction Details
Brand Names Associated with Nortriptyline
- Aventyl®
- Nortriptyline
- Pamelor®
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Dec 03, 2023
Interaction Effect
An increased risk of bleeding
Interaction Summary
Tricyclic antidepressants (TCAs) may increase the half-life and bioavailability of oral anticoagulants. Considerable interindividual differences may be found .
Severity
Moderate
Onset
Delayed
Evidence
Probable
How To Manage Interaction
In patients receiving tricyclic antidepressants and oral anticoagulant therapy, the prothrombin time ratio or INR (international normalized ratio) should be closely monitored with the addition and withdrawal of the antidepressant, and should be periodically reassessed during concurrent therapy. Achieving a stable drug regimen which produces the desired level of anticoagulation may be difficult in patients on this combination, and frequent adjustments of the anticoagulant dose may be required.
Mechanism Of Interaction
Decreased acenocoumarol metabolism; increased acenocoumarol absorption
Literature Reports
A) In a study of healthy volunteers, the concurrent use of nortriptyline or amitriptyline resulted in an increase of dicumarol levels and an increase in the plasma half-life of dicumarol, although the effect was not consistent in all subjects . This effect was not observed with warfarin.
B) A single oral dose of bishydroxycoumarin after 8 days of nortriptyline resulted in a significantly prolonged half-life and decreased volume of distribution of the coumarin anticoagulant in 6 healthy volunteers . The mechanism of action was suggested to be reduced bishydroxycoumarin metabolism and/or altered coumarin absorption.
C) Drug dosing was studied in 16 patients on long-term anticoagulant therapy who used concurrent TCAs . TCAs affected the stability of anticoagulant control leading to frequent changes in the doses of anticoagulants. Inhibition of coumarin metabolism was the postulated mechanism.
Nortriptyline Overview
-
Nortriptyline is used to treat depression. Nortriptyline is in a group of medications called tricyclic antidepressants. It works by increasing the amounts of certain natural substances in the brain that are needed to maintain mental balance.
Return To Our Drug Interaction Homepage
Feedback, Question Or Comment About This Information?
Ask Dr. Brian Staiger, PharmD, our medical editor, directly! He's always more than happy to assist.
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.