Estradiol with Mavacamten Interaction Details

Brand Names Associated with Estradiol

Brand Names Associated with Mavacamten

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

Interaction Effect

Reduced hormonal contraceptive exposure

Interaction Summary

Concomitant administration of mavacamten, a CYP3A4 inducer, and progestin and/or ethinyl estradiol, CYP3A4 substrates, may decrease exposures of progestin and ethinyl estradiol, which may lead to contraceptive failure or an increase in breakthrough bleeding. Patients should use a contraceptive method that is not affected by CYP450 enzyme induction (e.g., intrauterine system) or add nonhormonal contraception (e.g., condoms) during treatment with mavacamten and for 4 months after the last mavacamten dose.

Severity

Major

Onset

Unspecified

Evidence

Theoretical

How To Manage Interaction

Concomitant administration of mavacamten, a CYP3A4 inducer, and progestin and/or ethinyl estradiol, CYP3A4 substrates, may decrease exposures of progestin and ethinyl estradiol, which may lead to contraceptive failure or an increase in breakthrough bleeding. Patients should use a contraceptive method that is not affected by CYP450 enzyme induction (e.g., intrauterine system) or add nonhormonal contraception (e.g., condoms) during treatment with mavacamten and for 4 months after the last mavacamten dose.

Mechanism Of Interaction

Induction of CYP3A4-mediated metabolism of hormonal contraceptive by mavacamten

Literature Reports

A) Concomitant use of a 16-day course of the CYP3A4 inducer mavacamten (25 mg on days 1 and 2, followed by 15 mg for 14 days) with midazolam, a CYP3A4 substrate, resulted in a 13% decrease in midazolam AUC(inf) and a 7% decrease in Cmax, in healthy CYP2C19 normal metabolizers. Following coadministration of mavacamten once daily in patients with hypertrophic cardiomyopathy, midazolam AUC(inf) is predicted to decrease by 21% to 64% and Cmax is predicted to decrease by 13% to 48%, depending on the dose of mavacamten and CYP2C19 phenotype .

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.

Mavacamten Overview

• Mavacamten is used to treat adults with symptomatic obstructive hypertrophic cardiomyopathy. Mavacamten is in a class of medications called cardiac myosin inhibitors. It works by reducing the interaction between actin and myosin (proteins responsible for the contraction of the heart) so that the heart does not squeeze so hard.

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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.