Atazanavir with Rifampin Interaction Details

Brand Names Associated with Atazanavir

Brand Names Associated with Rifampin

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated Feb 29, 2024

Interaction Effect

Reduced atazanavir exposure and reduced efficacy of rifAMPin

Interaction Summary

Concomitant use of atazanavir and rifAMPin is contraindicated[1]. Coadministration of atazanavir/ritonavir and rifAMPin resulted in decreased atazanavir plasma concentrations and AUC. This may reduce the therapeutic effect of atazanavir and lead to the development of resistance [2]. When necessary, rifabutin 150 mg every other day or three times weekly should be used in place of rifAMPin in patients receiving ritonavir-boosted atazanavir; alternatively, some experts recommend using rifabutin 150 mg daily or 300 mg three times a week. Monitoring for rifabutin efficacy is recommended due to reports of inadequate rifabutin levels (at 150 mg three times a week) and acquired rifamycin resistance in patients with HIV-associated tuberculosis receiving lopinavir/ritonavir concurrently [3].

Severity

Contraindicated

Onset

Unspecified

Evidence

Established

How To Manage Interaction

Coadministration of atazanavir and rifAMPin is contraindicated[1]. Coadministration of atazanavir/ritonavir and rifAMPin resulted in decreased atazanavir plasma concentrations. This may reduce the therapeutic effect of atazanavir and lead to the development of resistance [2]. When necessary, rifabutin 150 mg every other day or three times a week should be used in place of rifAMPin in patients receiving ritonavir-boosted atazanavir; alternatively, some experts recommend using rifabutin 150 mg daily or 300 mg three times a week. Monitoring for rifabutin efficacy is recommended due to reports of inadequate rifabutin levels (at 150 mg three times a week) and acquired rifamycin resistance in patients with HIV-associated tuberculosis receiving lopinavir/ritonavir concurrently [3].

Mechanism Of Interaction

Induction of CYP3A-mediated metabolism of atazanavir by rifAMPin

Literature Reports

A) Coadministration of rifAMPin with an atazanavir/ritonavir combination regimen significantly reduced the serum plasma level of atazanavir. RifAMPin 600 mg once daily administered with atazanavir 300 mg/ritonavir 100 mg once daily in 16 subjects resulted in a significant decline in atazanavir Cmax, AUC, and Cmin by 53%, 72% and 98%, respectively [2].

References

1 ) Product Information: RIFADIN(R) oral capsules, intravenous injection, rifampin oral capsules, intravenous injection. sanofi-aventis U.S. LLC, Bridgewater, NJ, 2010.

2 ) Product Information: REYATAZ(R) oral capsules, oral powder, atazanavir oral capsules, oral powder. Bristol-Myers Squibb Company (per FDA), Princeton, NJ, 2020.

3 ) U.S. Department of Health and Human Services: Guidelines for the use of antiretroviral agents in HIV-1-Infected adults and adolescents. U.S. Department of Health and Human Services. Washington, DC. 2011. Available from URL: http://aidsinfo.n... . As accessed 2011-10-17.

Atazanavir Overview

• 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.

Rifampin Overview

• Rifampin is used with other medications to treat tuberculosis (TB; a serious infection that affects the lungs and sometimes other parts of the body). Rifampin is also used to treat some people who have Neisseria meningitidis (a type of bacteria that can cause a serious infection called meningitis) infections in their noses or throats. These people have not developed symptoms of the disease, and this treatment is used to prevent them from infecting other people. Rifampin should not be used to treat people who have developed symptoms of meningitis. Rifampin is in a class of medications called antimycobacterials. It works by killing the bacteria that cause infection.

• Antibiotics such as rifampin will not work for colds, flu, or other viral infections. Using antibiotics when they are not needed increases your risk of getting an infection later that resists antibiotic treatment.

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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:

• Gold Standard Drug Database
• Micromedex
• Lexicomp
• DrugBank

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.