Quetiapine with Posaconazole Interaction Details
Brand Names Associated with Quetiapine
- Quetiapine
- Seroquel®
- Seroquel® XR
Brand Names Associated with Posaconazole
- Noxafil PowderMix®
- Noxafil®
- Posaconazole
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Nov 08, 2023
Interaction Effect
Increased exposure of quetiapine and increased risk of QT-interval prolongation
Interaction Summary
Posaconazole is a strong CYP3A4 inhibitor and is independently capable of prolonging the QT interval. Cases of torsade de pointes have been reported with the use of posaconazole. Use of posaconazole with quetiapine, a CYP3A4 substrate that also prolongs the QT interval, is contraindicated as concomitant use may lead to increased quetiapine exposure and increased risk of QT interval prolongation and torsade de pointes.
Severity
Contraindicated
Onset
Unspecified
Evidence
Theoretical
How To Manage Interaction
Posaconazole is a strong CYP3A4 inhibitor and is independently capable of prolonging the QT interval. Use of posaconazole with CYP3A4 substrates that also prolong the QT interval, such as quetiapine, is contraindicated as concomitant use may lead to increased exposure to quetiapine and increased risk of QT interval prolongation and torsade de pointes.
Mechanism Of Interaction
Inhibition of CYP3A4-mediated metabolism of quetiapine by posaconazole; additive QT-interval prolongation
Quetiapine Overview
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Quetiapine tablets and extended-release (long-acting) tablets are used to treat the symptoms of schizophrenia (a mental illness that causes disturbed or unusual thinking, loss of interest in life, and strong or inappropriate emotions). Quetiapine tablets and extended-release tablets are also used alone or with other medications to treat episodes of mania (frenzied, abnormally excited or irritated mood) or depression in patients with bipolar disorder (manic depressive disorder; a disease that causes episodes of depression, episodes of mania, and other abnormal moods). In addition, quetiapine tablets and extended-release tablets are used with other medications to prevent episodes of mania or depression in patients with bipolar disorder. Quetiapine extended-release tablets are also used along with other medications to treat depression. Quetiapine tablets may be used as part of a treatment program to treat bipolar disorder and schizophrenia in children and teenagers. Quetiapine is in a class of medications called atypical antipsychotics. It works by changing the activity of certain natural substances in the brain.
Posaconazole Overview
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Posaconazole is used to prevent serious fungal infections that can spread throughout the body in adults and children 2 years of age and older with a weakened ability to fight infection. Posaconazole delayed-release tablets are used to treat invasive aspergillosis (a serious fungal infection that begins in the lungs and spreads through the bloodstream to other organs) in adults and teenagers 13 years of age and older. Posaconazole oral suspension is also used to treat yeast infections of the mouth and throat including yeast infections in adults and teenagers 13 years of age and older that could not be treated successfully with other medications. Posaconazole is in a class of medications called azole antifungals. It works by slowing the growth of fungi that cause infection.
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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.