Estradiol with Darunavir Interaction Details

Brand Names Associated with Estradiol

Brand Names Associated with Darunavir

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated Nov 13, 2023

Interaction Effect

Reduced hormonal contraceptives exposure and reduced efficacy of hormonal contraceptives

Interaction Summary

COCs have shown significant decrease in plasma concentrations of estrogen and/or progestin during coadministration with darunavir/ritonavir. Coadministration of darunavir/ritonavir with estrogen-based contraceptives led to significantly decreased plasma concentrations of ethinyl estradiol and norethindrone in 1 study . Consider supplementary or non-hormonal contraception options for women of childbearing potential during darunavir therapy, as no data are available to provide guidance on coadministration of darunavir with oral or other hormonal contraceptives .

Severity

Major

Onset

Unspecified

Evidence

Probable

How To Manage Interaction

Combination oral contraceptives (COCs) have shown significant decrease in plasma concentrations of estrogen and/or progestin during coadministration with darunavir/ritonavir. Consider supplementary or non-hormonal contraception options for women of childbearing potential during darunavir therapy, as no data are available to provide guidance on coadministration of darunavir with oral or other hormonal contraceptives .

Mechanism Of Interaction

Unknown

Literature Reports

A) An open-label, randomized, crossover study in 19 healthy, HIV-negative females aged 18 to 43 years (median, 34 years) revealed that coadministration of ethinyl estradiol/norethindrone with darunavir/ritonavir resulted in significantly lower exposure and mean plasma concentrations of ethinyl estradiol and norethindrone. Compared to administration of ethinyl estradiol and norethindrone alone, coadministration with darunavir/ritonavir led to decreases in ethinyl estradiol Cmin, Cmax, and AUC of 62%, 32%, and 44%, respectively. Similarly, norethindrone Cmin, Cmax, and AUC decreased by 30%, 10%, and 14%, respectively. There were no significant changes in darunavir or ritonavir pharmacokinetic parameters .

Estradiol Overview

• Estrogen is used to treat hot flushes ('hot flashes'; sudden strong feelings of heat and sweating) in women who are experiencing menopause ('change of life', the end of monthly menstrual periods). Some brands of estrogen are also used to treat vaginal dryness, itching, or burning, or to prevent osteoporosis (a condition in which the bones become thin and weak and break easily) in women who are experiencing or have experienced menopause. However, women who need a medication only to treat vaginal dryness or only to prevent osteoporosis should consider a different treatment. Some brands of estrogen are also to relieve symptoms of low estrogen in young women who do not produce enough estrogen naturally. Some brands of estrogen are also used to relieve the symptoms of certain types of breast and prostate (a male reproductive gland) cancer. Estrogen is in a class of medications called hormones. It works by replacing estrogen that is normally produced by the body.

Darunavir Overview

• Darunavir is used with a pharmacokinetic booster (a medication that increases the amount of other medications in the body) such as ritonavir (Norvir) or cobicistat (Tybost), and other medications to treat human immunodeficiency virus (HIV) infection in adults and children 3 years of age and older. Darunavir is in a class of medications called protease inhibitors. It works by decreasing the amount of HIV in the blood. Although darunavir 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 life-style changes may decrease the risk of transmitting 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:

• 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.