Digoxin with Fluoxetine Interaction Details
Brand Names Associated with Digoxin
- Cardoxin®
- Digitek®
- Digoxin
- Lanoxicaps®
- Lanoxin®
Brand Names Associated with Fluoxetine
- Fluoxetine
- Prozac®
- Prozac® Weekly
- Rapiflux®
- Sarafem®
- Selfemra®
- Symbyax® (as a combination product containing Fluoxetine, Olanzapine)
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Jan 08, 2024
Interaction Effect
Increased digoxin exposure and an increased risk of digoxin toxicity (nausea, vomiting, arrhythmias)
Interaction Summary
Coadministration of FLUoxetine to a patient taking another drug that is tightly bound to protein like digitoxin may cause a shift in plasma concentrations potentially resulting in an adverse effect since FLUoxetine is tightly bound to plasma proteins. The interaction between FLUoxetine and other highly protein-bound drugs has not been fully evaluated, but may be important. One case report describes a 93-year-old female stabilized on digoxin who experienced toxic levels of digoxin after FLUoxetine had been added to her regimen for depression. Rechallenge with FLUoxetine again caused her digoxin levels to increase dramatically. While the mechanism of this interaction is not clear, it could be related to displacement of digoxin from binding sites or reduced clearance of digoxin .
Severity
Major
Onset
Delayed
Evidence
Probable
How To Manage Interaction
Coadministration of FLUoxetine to a patient taking another drug that is tightly bound to protein like digitoxin may cause a shift in plasma concentrations potentially resulting in an adverse effect since FLUoxetine is tightly bound to plasma proteins. Patients receiving FLUoxetine and digoxin therapy concomitantly should be monitored for increasing levels of digoxin, along with signs and symptoms of digoxin toxicity, including anorexia .
Mechanism Of Interaction
Displacement of protein-bound FLUoxetine
Literature Reports
A) Digoxin 0.125 mg daily was being administered to a 93-year-old female for congestive heart failure and paroxysmal atrial fibrillation. Digoxin levels ranged from 1.0 to 1.4 nmol/L during the two months preceding the initiation of FLUoxetine 10 mg daily. Within one week, the patient complained of anorexia. Her digoxin level measured 4.2 nmol/L, while renal function and potassium levels remained unchanged. Both digoxin and FLUoxetine were discontinued, and her digoxin level returned to normal in five days with resolution of the anorexia. During the next three weeks her digoxin serum levels ranged from 0.9 nmol/L to 1.4 nmol/L. Because the symptoms of depression persisted, FLUoxetine was again initiated at 10 mg daily and the digoxin serum level was closely monitored. After two days of FLUoxetine therapy, the digoxin level increased to 2.0 nmol/L, and after four days it was 2.8 nmol/L. Renal function remained unchanged, as did serum electrolytes. The patient again experienced anorexia, and treatment with FLUoxetine was discontinued .
B) The interaction between FLUoxetine and other highly protein-bound drugs has not been fully evaluated, but may be important .
Digoxin Overview
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Digoxin is used to treat heart failure and abnormal heart rhythms (arrhythmias). It helps the heart work better and it helps control your heart rate.
Fluoxetine Overview
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Fluoxetine is used to treat depression, obsessive-compulsive disorder (bothersome thoughts that won't go away and the need to perform certain actions over and over), some eating disorders, and panic attacks (sudden, unexpected attacks of extreme fear and worry about these attacks). Fluoxetine is also used to relieve the symptoms of premenstrual dysphoric disorder, including mood swings, irritability, bloating, and breast tenderness. It is also used along with olanzapine (Zyprexa) to treat depression that did not respond to other medications and episodes of depression in people with bipolar I disorder (manic-depressive disorder; a disease that causes episodes of depression, episodes of mania, and other abnormal moods). Fluoxetine is in a class of medications called selective serotonin reuptake inhibitors (SSRIs). It works by increasing the amount of serotonin, a natural substance in the brain that helps maintain mental balance.
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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.