Amiodarone with Digitoxin Interaction Details
Brand Names Associated with Amiodarone
- Amiodarone
- Cordarone®
- Pacerone®
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Feb 27, 2024
Interaction Effect
Digitoxin toxicity (nausea, vomiting, cardiac arrhythmias)
Interaction Summary
Amiodarone taken concomitantly with digoxin increases the serum digoxin concentration by 70% after one day, and similar changes are expected to occur with digitoxin[1]. Cases of asystole and torsades de pointes occurring related to concomitant digoxin and amiodarone therapy have been reported [2][3]. When amiodarone is initiated, consider discontinuing digitoxin. If amiodarone and digitoxin are taken concomitantly, reduce the digitoxin dose by approximately 50% and monitor serum digitoxin levels closely [1].
Severity
Moderate
Onset
Delayed
Evidence
Probable
How To Manage Interaction
When amiodarone is administered to patients taking digitoxin, consider discontinuing digitoxin, or reduce the digitoxin dose by approximately 50%. If digitoxin is continued, closely monitor serum digitoxin levels and clinical evidence of digitoxin toxicity.
Mechanism Of Interaction
Inhibition of p-glycoprotein by amiodarone
Literature Reports
A) In patients receiving digoxin therapy, administration of oral amiodarone regularly results in an increase in serum digoxin concentration that may reach toxic levels with resultant clinical toxicity. Amiodarone taken concomitantly with digoxin increases the serum digoxin concentration by 70% after one day. On administration of oral amiodarone, the need for digitalis therapy should be reviewed and the dose reduced by approximately 50% or discontinued. If digitalis treatment is continued, serum levels should be closely monitored and patients observed for clinical evidence of toxicity. These precautions probably should apply to digitoxin administration as well [4].
References
1 ) Product Information: Cordarone(R) IV, amiodarone. Wyeth Laboratories, Philadelphia, PA, 2002.
2 ) Bajaj BP, Baig MW, & Perrins EJ: Amiodarone-induced torsades de pointes: the possible facilitatory role of digoxin. Int J Cardiol 1991; 33(2):335-337.
3 ) Klein HO, Beker B, DiSegni E, et al: Asystole produced by the combination of amiodarone and digoxin. Am Heart J 1987; 113:399-400.
4 ) Product Information: Cordarone(R) IV, amiodarone. Wyeth Laboratories, Philadelphia, PA, 2002.
Amiodarone Overview
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Amiodarone is used to treat and prevent certain types of serious, life-threatening ventricular arrhythmias (a certain type of abnormal heart rhythm when other medications did not help or could not be tolerated. Amiodarone is in a class of medications called antiarrhythmics. It works by relaxing overactive heart muscles.
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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.