Venlafaxine with Imipramine Interaction Details
Brand Names Associated with Venlafaxine
- Effexor®
- Effexor® XR
- Venlafaxine
Brand Names Associated with Imipramine
- Imipramine
- Tofranil®
- Tofranil® PM
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Nov 12, 2023
Interaction Effect
An increased risk of cardiotoxicity (QT prolongation, torsades de pointes, cardiac arrest) and adverse effects of both drugs
Interaction Summary
Tricyclic antidepressants (TCAs) and venlafaxine have been shown to prolong the QTc interval at the recommended therapeutic dose. Even though no formal drug interaction studies have been done, the coadministration of tricyclic antidepressants and other drugs known to prolong the QTc interval, such as venlafaxine, is not recommended . In addition, venlafaxine and tricyclic antidepressants (TCAs) may competitively inhibit each other's metabolism which may increase side effects of both drugs . Venlafaxine increased the AUC, Cmax, and Cmin of desipramine by approximately 35%. The AUCs of 2-OH-desipramine increased by 2.5 and 4.5 fold when administered with venlafaxine 37.5 mg and 75 mg every 12 hours, respectively. The pharmacokinetics of imipramine and the 2-hydroxy metabolite were not affected .
Severity
Major
Onset
Rapid
Evidence
Theoretical
How To Manage Interaction
Due to the potential for additive effects on the QT interval, the concurrent administration of venlafaxine and tricyclic antidepressants is not recommended.
Mechanism Of Interaction
Decreased TCA and venlafaxine metabolism; additive effects on QT prolongation
Literature Reports
A) When administered with imipramine, the pharmacokinetics of imipramine and the 2-hydroxy metabolite were not affected. Venlafaxine increased the area under the concentration-time curve (AUC), maximum concentration (Cmax), and minimum concentration (Cmin) of desipramine by approximately 35%. The 2-OH-desipramine AUCs increased by 2.5-fold (venlafaxine 37.5 mg every 12 hours) and by 4.5-fold (venlafaxine 75 mg every 12 hours). The clinical significance of this finding is unknown .
Venlafaxine Overview
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Venlafaxine is used to treat depression. Venlafaxine extended-release (long-acting) capsules are also used to treat generalized anxiety disorder (GAD; excessive worrying that is difficult to control), social anxiety disorder (extreme fear of interacting with others or performing in front of others that interferes with normal life), and panic disorder (sudden, unexpected attacks of extreme fear and worry about these attacks). Venlafaxine is in a class of medications called selective serotonin and norepinephrine reuptake inhibitors (SNRIs). It works by increasing the amounts of serotonin and norepinephrine, natural substances in the brain that help maintain mental balance.
Imipramine Overview
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Imipramine tablets and capsules are used to treat depression. Imipramine tablets are also used to prevent bedwetting in children. Imipramine is in a class of medications called tricyclic antidepressants. It treats depression by increasing the amounts of certain natural substances in the brain that are needed to maintain mental balance. There is not enough information to explain how imipramine prevents bedwetting.
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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.