Atazanavir with Etravirine Interaction Details
Brand Names Associated with Atazanavir
- Atazanavir
- ATZ
- Reyataz®
Brand Names Associated with Etravirine
- Etravirine
- Intelence®
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Feb 29, 2024
Interaction Effect
Reduced atazanavir exposure and an increased etravirine exposure
Interaction Summary
Atazanavir (with or without ritonavir) and etravirine should not be coadministered. The combination of atazanavir (with or without ritonavir) and etravirine has resulted in significant decreases in atazanavir Cmin and may result in significant increases in systemic exposure of etravirine (based on studies with a background regimen of darunavir/ritonavir) due to induction of CYP3A4-mediated metabolism of atazanavir and inhibition of CYP3A4-mediated metabolism of etravirine[1]. Coadministration of atazanavir/cobicistat with etravirine is not recommended because it may result in the loss of therapeutic effect and development of resistance to atazanavir [2].
Severity
Major
Onset
Unspecified
Evidence
Established
How To Manage Interaction
Atazanavir (with or without ritonavir) and etravirine should not be coadministered. Concomitant use of atazanavir and etravirine may result in decreases in atazanavir plasma concentrations and increases in etravirine systemic exposure due to induction of CYP3A4-mediated metabolism of atazanavir and inhibition of CYP3A4-mediated metabolism of etravirine[1]. Coadministration of atazanavir/cobicistat with etravirine is not recommended because it may result in the loss of therapeutic effect and development of resistance to atazanavir [2].
Mechanism Of Interaction
Induction of CYP3A4-mediated metabolism of atazanavir; inhibition of CYP3A4-mediated metabolism of etravirine
Literature Reports
A) Concomitant administration of atazanavir (with or without ritonavir) and etravirine resulted in decreased atazanavir AUC and plasma concentrations. When atazanavir 400 mg once daily was administered concurrently with etravirine 200 mg twice daily in 14 patients, the ratio of atazanavir pharmacokinetic parameters with etravirine to without etravirine was: Cmax 0.97 (90% confidence interval (CI), 0.73 to 1.29), AUC 0.83 (90% CI, 0.63 to 1.09), and Cmin 0.53 (90% CI, 0.38 to 0.73). When the combination of atazanavir 300 mg/ritonavir 100 mg once daily was administered concurrently with etravirine 200 mg twice daily in 13 patients, the ratio of atazanavir/ritonavir pharmacokinetic parameters with etravirine to without etravirine was: Cmax 0.97 (90% CI, 0.89 to 1.05), AUC 0.86 (90% CI, 0.79 to 0.93), and Cmin 0.62 (90% CI, 0.55 to 0.71) [1].
B) Concomitant administration of atazanavir (with or without ritonavir) and etravirine resulted in increased etravirine AUC and plasma concentrations. When atazanavir 400 mg once daily was administered concurrently with etravirine 200 mg twice daily in 14 patients, the ratio of etravirine pharmacokinetic parameters with atazanavir to without atazanavir was: Cmax 1.47 (90% confidence interval (CI), 1.36 to 1.59), AUC 1.5 (90% CI, 1.41 to 1.59), and Cmin 1.58 (90% CI, 1.46 to 1.7). If the combination of atazanavir 300 mg/ritonavir 100 mg once daily is administered concurrently with etravirine 200 mg twice daily, the ratio of etravirine pharmacokinetic parameters with atazanavir/ritonavir to without atazanavir/ritonavir is expected to be as follows: Cmax 1.3 (90% CI, 1.17 to 1.44), AUC 1.3 (90% CI, 1.18 to 1.44), and Cmin 1.26 (90% CI, 1.12 to 1.42). This expected increase in systemic exposure of etravirine when coadministered with atazanavir/ritonavir is based on comparing exposures of etravirine in drug-drug interaction studies with exposure in trials in which the background regimen contained darunavir/ritonavir [1].
References
1 ) Product Information: INTELENCE(R) oral tablets, etravirine oral tablets. Tibotec, Inc., Raritan, NJ, 2009.
2 ) Product Information: EVOTAZ(R) oral tablets, atazanavir cobicistat oral tablets. Bristol-Myers Squibb Company (per FDA), Princeton, NJ, 2023.
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.
Etravirine Overview
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Etravirine is used along with other medications to treat human immunodeficiency virus (HIV) infection in adults and children 2 years of age and older who no longer benefit from taking other HIV medications. Etravirine is in a class of medications called non-nucleoside reverse transcriptase inhibitors (NNRTIs). It works by decreasing the amount of HIV in the blood. Although etravirine 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. Taking these medications along with practicing safer sex and making other lifestyle changes may decrease the risk of transmitting (spreading) the HIV virus to other people.
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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.