Atazanavir with Vinblastine Interaction Details

Brand Names Associated with Atazanavir

Brand Names Associated with Vinblastine

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

Interaction Effect

Increased risk of severe vinBLAStine-related toxicity (constipation, neutropenia, peripheral neuropathy)

Interaction Summary

Coadministration of atazanavir (moderate CYP3A inhibitor) with a CYP3A substrate, such as vinBLAStine, may increase vinBLAStine plasma concentrations and the risk for or severity of adverse effects[1][2]. In a retrospective review of patients treated with vinBLAStine (N=16), protease inhibitor use, including atazanavir, significantly increased the risk for Grade 3 to 4 neutropenia (OR, 34.3) compared with non-protease inhibitor-based antiretroviral regimens [3]. The magnitude of CYP3A-mediated drug interactions may change when atazanavir is coadministered with ritonavir [1]. Consider temporarily withholding ritonavir-containing regimens in patients who develop significant hematologic or gastrointestinal side effects with concomitant use [4].

Severity

Major

Onset

Delayed

Evidence

Probable

How To Manage Interaction

Coadministration of atazanavir (moderate CYP3A inhibitor) with a CYP3A substrate, such as vinBLAStine, may increase plasma concentrations of vinBLAStine and the risk or severity of adverse effects[1][2]. The magnitude of CYP3A-mediated drug interactions on the coadministered drug may change when atazanavir is coadministered with ritonavir [1]. Consider temporarily withholding ritonavir-containing regimens in patients who develop significant hematologic or gastrointestinal side effects with concomitant use [4].

Mechanism Of Interaction

Inhibition of CYP3A-mediated vinBLAStine metabolism

Literature Reports

A) Protease inhibitor use (n=9) was associated with a significantly higher risk for severe Grade 3 to 4 neutropenia (OR, 34.3 [95% CI, 1.9 to 602.4]) compared with non-protease inhibitor based antiretroviral regimens (n=7) in a retrospective review of HIV-infected patients with Hodgkin lymphoma treated with vinBLAStine-containing regimens and combination antiretroviral therapy. There was an inverse correlation between dosage of ritonavir and mean neutrophil nadir in patients with ritonavir-boosted regimens (mean neutrophil nadir, 1.35 x 10(6)/L in patients not taking ritonavir, 0.85 x 10(6)/L with ritonavir 100 mg, and 0.047 x 10(6)/L with ritonavir 200 mg). Included protease inhibitors were atazanavir, ritonavir, indinavir, and lopinavir [3].

References

1 ) Product Information: REYATAZ(R) oral capsules, oral powder, atazanavir oral capsules, oral powder. Bristol-Myers Squibb Company (per manufacturer), Princeton, NJ, 2018.

2 ) Product Information: Vinblastine sulfate intravenous injection, vinblastine sulfate intravenous injection. Fresenius Kabi USA LLC (per DailyMed), Lake Zurich, IL, 2016.

3 ) Cingolani A, Torti L, Pinnetti C, et al: Detrimental clinical interaction between ritonavir-boosted protease inhibitors and vinblastine in HIV-infected patients with Hodgkin's lymphoma. AIDS 2010; 24(15):2408-2412.PubMed Abstract: http://www.ncbi.nlm.nih.gov/...

4 ) Product Information: NORVIR(R) oral tablets, oral solution, oral powder, ritonavir oral tablets, oral solution, oral powder. AbbVie Inc (per FDA), North Chicago, IL, 2019.

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.

Vinblastine Overview

• Vinblastine is used in combination with other chemotherapy drugs to treat Hodgkin's lymphoma (Hodgkin's disease) and non-Hodgkin's lymphoma (types of cancer that begin in a type of white blood cell that normally fights infection), and cancer of the testicles. It is also used to treat Langerhans cell histiocytosis (histiocytosis X; Letterer-Siwe disease; a condition in which too many of a certain type of white blood cell grows in parts of the body). It may also be used to treat breast cancer that has not improved after treatment with other medications and gestational trophoblastic tumors (a type of tumor that forms inside a woman's uterus while she is pregnant) that has not improved after surgery or treatment with other medications. Vinblastine is in a class of medications called vinca alkaloids. It works by slowing or stopping the growth of cancer cells in your body.

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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.