Atazanavir with Voriconazole Interaction Details
Brand Names Associated with Atazanavir
- Atazanavir
- ATZ
- Reyataz®
Brand Names Associated with Voriconazole
- Vfend®
- Voriconazole
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Feb 29, 2024
Interaction Effect
Altered atazanavir and/or voriconazole exposure and an increased risk of QT interval prolongation
Interaction Summary
Coadministration of atazanavir and voriconazole is contraindicated due to potential for QT prolongation and rare occurrences of torsade de pointes[1]. Coadministration of voriconazole in patients receiving atazanavir with ritonavir is not recommended unless an assessment of the benefit/risk to the patient justifies the use of voriconazole. When coadministered, carefully monitor for voriconazole-associated adverse reactions and loss of either voriconazole or atazanavir efficacy. Coadministration of voriconazole with atazanavir without ritonavir may affect atazanavir concentrations; however, no data are available [2].
Severity
Contraindicated
Onset
Unspecified
Evidence
Theoretical
How To Manage Interaction
Coadministration of atazanavir and voriconazole is contraindicated due to potential for QT prolongation and rare occurrences of torsade de pointes[1]. Coadministration of voriconazole in patients receiving atazanavir with ritonavir is not recommended unless an assessment of the benefit/risk to the patient justifies the use of voriconazole. When coadministered, carefully monitor for voriconazole-associated adverse reactions and loss of either voriconazole or atazanavir efficacy. Coadministration of voriconazole with atazanavir without ritonavir may affect atazanavir concentrations; however, no data are available [2].
Mechanism Of Interaction
Unknown; additive QT interval prolongation
Literature Reports
A) In a study, coadministration of voriconazole with an atazanavir/ritonavir combination regimen in subjects without a functional CYP2C19 allele reduced the serum plasma level of atazanavir. Voriconazole 50 mg twice daily (Day 2 to 3 and Day 22 to 30) and 100 mg twice daily (Day 1 and Day 21) administered with atazanavir 300 mg/ritonavir 100 mg once daily (Day 11 to 30) in 20 subjects resulted in a decline in atazanavir Cmax, AUC, and Cmin by 19%, 20% and 31%, respectively and a decline in voriconazole Cmax, AUC and Cmin by 10%, 33% and 39% respectively, whereas there is huge increase in the Cmax, AUC and Cmin of voriconazole by 338%, 461% and 665% respectively [2].
B) In another study, coadministration of voriconazole with an atazanavir/ritonavir combination regimen in subjects with at least one functional CYP2C19 allele reduced the serum plasma level of atazanavir. Voriconazole 200 mg twice daily (Day 2 to 3 and Day 22 to 30) and 400 mg twice daily (Day 1 and Day 21) administered with atazanavir 300 mg/ritonavir 100 mg once daily (Day 11 to 30) in 20 subjects resulted in a decline in atazanavir Cmax, AUC, and Cmin by 13%, 12% and 20%, respectively and a decline in voriconazole Cmax, AUC and Cmin by 10%, 33% and 39% respectively [2].
References
1 ) Product Information: VFEND(R) oral tablets, oral suspension, intravenous injection, voriconazole oral tablets, oral suspension, intravenous injection. Roerig (per FDA), New York, NY, 2022.
2 ) Product Information: REYATAZ(R) oral capsules, oral powder, atazanavir oral capsules, oral powder. Bristol-Myers Squibb Company (per FDA), Princeton, NJ, 2020.
Atazanavir Overview
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Atazanavir is used along with other medications to treat human immunodeficiency virus (HIV) infection in adults and children who are at least 3 months of age and weigh at least 22 lb (10 kg). Atazanavir is in a class of medications called protease inhibitors. It works by decreasing the amount of HIV in the blood. Although atazanavir does not cure HIV, it may decrease your chance of developing acquired immunodeficiency syndrome (AIDS) and HIV-related illnesses such as serious infections or cancer. Atazanavir must be given with other medications that treat HIV infection to completely treat the infection. Taking these medications along with practicing safer sex and making other lifestyle changes may decrease the risk of transmitting the HIV virus to other people.
Voriconazole Overview
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Voriconazole is used in adults and children 2 years of age and older to treat serious fungal infections such as invasive aspergillosis (a fungal infection that begins in the lungs and spreads through the bloodstream to other organs), esophageal candidiasis (a yeast [a type of fungus] infection that may cause white patching in the mouth and throat), and candidemia (a fungal infection in the blood). It is also used to treat certain other fungal infections when other medications will not work for certain patients. Voriconazole is in a class of antifungal medications called triazoles. It works by slowing the growth of the 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.