Fluoxetine with Galantamine Interaction Details
Brand Names Associated with Fluoxetine
- Fluoxetine
- Prozac®
- Prozac® Weekly
- Rapiflux®
- Sarafem®
- Selfemra®
- Symbyax® (as a combination product containing Fluoxetine, Olanzapine)
Brand Names Associated with Galantamine
- Galantamine
- Razadyne® (formerly available as Reminyl®)
- Razadyne® ER
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Nov 11, 2023
Interaction Effect
Increased galantamine exposure and an increased risk of QT interval prolongation
Interaction Summary
Coadministration of FLUoxetine, a CYP2D6 inhibitor and QT prolonging drug, and galantamine, a CYP2D6 substrate and QT prolonging drug, may result in increased galantamine exposure and additive effects on the QT-interval. If concomitant use is required, monitor for galantamine toxicity including anorexia, nausea, vomiting, dizziness, arrhythmias or gastrointestinal bleeding and consider periodic ECG monitoring. Discontinue use if symptoms of ventricular arrhythmia occur .
Severity
Major
Onset
Unspecified
Evidence
Probable
How To Manage Interaction
Concomitant administration of FLUoxetine, a CYP2D6 inhibitor and QT prolonging drug, and galantamine, a CYP2D6 substrate and QT prolonging drug, should be avoided as this may result in increased galantamine exposure. Additionally, concomitant administration of FLUoxetine and galantamine may result in additive effects on the QT interval. If coadministration is required, monitor for galantamine toxicity including anorexia, nausea, vomiting, dizziness, arrhythmias, or gastrointestinal bleeding and consider periodic ECG monitoring. Discontinue use if symptoms of ventricular arrhythmia occur .
Mechanism Of Interaction
Inhibition of CYP2D6-mediated galantamine metabolism; additive QT interval prolongation
Literature Reports
A) Based upon in vitro studies, the major enzymes involved in galantamine metabolism are CYP3A4 and CYP2D6. FLUoxetine is a known inhibitor of CYP2D6. In a population pharmacokinetic analysis using a database of 852 Alzheimer's disease patients, several drugs which inhibit CYP2D6, including FLUoxetine (n=48), demonstrated a 25-33% decrease in galantamine clearance .
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.
Galantamine Overview
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Galantamine is used to treat the symptoms of Alzheimer's disease (AD; a brain disease that slowly destroys the memory and the ability to think, learn, communicate and handle daily activities). Galantamine is in a class of medications called acetylcholinesterase inhibitors. It works by increasing the amount of a certain natural substance in the brain that is needed for memory and thought. Galantamine may improve the ability to think and remember or slow the loss of these abilities in people who have AD. However, galantamine will not cure AD or prevent the loss of mental abilities at some time in the future.
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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.