Paroxetine with Pimozide Interaction Details
Brand Names Associated with Paroxetine
- Brisdelle®
- Paroxetine
- Paxil®
- Paxil® CR
- Pexeva®
Brand Names Associated with Pimozide
- Orap®
- Pimozide
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Nov 13, 2023
Interaction Effect
An increased risk of pimozide toxicity including cardiotoxicity (QT interval prolongation, torsades de pointes, cardiac arrest)
Interaction Summary
Coadministration of PARoxetine and pimozide is contraindicated. A controlled study involving concurrent administration of pimozide and PARoxetine to healthy volunteers resulted in a mean increase in AUC and Cmax of 151% and 62%, respectively. The consequence of such an extreme increase of pimozide plasma concentrations may be pimozide toxicity, including risk of QTc prolongation leading to ventricular arrhythmias and torsades de pointes.
Severity
Contraindicated
Onset
Rapid
Evidence
Probable
How To Manage Interaction
The concurrent administration of PARoxetine and pimozide (CYP2D6 substrate with narrow therapeutic index) is contraindicated due to the possibility of significantly increased pimozide plasma concentrations resulting in a dangerous risk of pimozide toxicity, including increased risk of QTc prolongation leading to ventricular arrhythmias and torsades de pointes.
Mechanism Of Interaction
Inhibition of CYP2D6-mediated pimozide metabolism by PARoxetine; additive QT interval prolongation
Literature Reports
A) A group of healthy volunteers in a controlled study received a single dose of 2 mg pimozide after being titrated up to a daily dose of 60 mg of immediate-release PARoxetine hydrochloride. The study resulted in a mean increase of pimozide AUC and Cmax of 151% and 62%, respectively, compared to pimozide administered alone .
Paroxetine Overview
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Paroxetine tablets, suspension (liquid), and extended-release (long-acting) tablets are used to treat depression, panic disorder (sudden, unexpected attacks of extreme fear and worry about these attacks), and social anxiety disorder (extreme fear of interacting with others or performing in front of others that interferes with normal life). Paroxetine tablets and suspension are also used to treat obsessive-compulsive disorder (bothersome thoughts that won't go away and the need to perform certain actions over and over), generalized anxiety disorder (GAD; excessive worrying that is difficult to control), and posttraumatic stress disorder (disturbing psychological symptoms that develop after a frightening experience). Paroxetine extended-release tablets are also used to treat premenstrual dysphoric disorder (PMDD, physical and psychological symptoms that occur before the onset of the menstrual period each month). Paroxetine capsules (Brisdelle) are used to treat hot flashes (sudden feelings of warmth, especially in the face, neck, and chest) in women who are experiencing menopause (stage of life when menstrual periods become less frequent and stop and women may experience other symptoms and body changes). Paroxetine is in a class of medications called selective serotonin-reuptake inhibitors (SSRIs). It treats depression and other mental illnesses by increasing the amount of serotonin, a natural substance in the brain that helps maintain mental balance. There is not enough information available at this time to know how paroxetine works to treat hot flashes.
Pimozide Overview
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Pimozide is used to control motor or verbal tics (an uncontrollable need to repeat certain movements or sounds) caused by Tourette's disorder (condition characterized by motor or verbal tics). Pimozide should only be used to treat people who cannot take other medications or who have taken other medications without good results. Pimozide should only be used to treat severe tics that stop the person from learning, working, or performing daily activities.
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Pimozide is in a class of medications called conventional antipsychotics. It works by decreasing abnormal excitement in the brain.
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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.