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Camzyos

mavacamten
Used for Cardiomyopathy

Camzyos (mavacamten) is a medication used for adults who have a genetic heart problem called hypertrophic cardiomyopathy (HCM). It works as a cardiac myosin inhibitor to relax the heart and get more blood pumped to the rest of the body. Camzyos (mavacamten) comes as a capsule that you take by mouth once a day. But it can have side effects like making you feel dizzy or faint. It also has a risk of causing heart failure. Because of this, you have to enroll in a special medication safety program called Risk Evaluation and Mitigation Strategy (REMS) for Camzyos (mavacamten).

Reviewed by:Last reviewed on July 29, 2025
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What is Camzyos (mavacamten)?

What is Camzyos (mavacamten) used for?

How Camzyos (mavacamten) works

Camzyos (mavacamten) is a cardiac myosin inhibitor. It attaches to a protein in the heart called myosin. Myosin helps your heart squeeze (contract) to pump blood through the body.

The myosin in people with HCM is more active than it should be. It causes the heart to contract too much and makes it hard for the heart to relax. This makes the walls of the heart become thick and stiff. People with obstructive HCM have heart muscles that are so thick that blood can't flow through well.

As a cardiac myosin inhibitor, Camzyos (mavacamten) stops myosin from working as well. This helps your heart relax so more blood can get to the heart to be pumped through the body. This can help relieve symptoms like heart palpitations and shortness of breath.

When does Camzyos (mavacamten) start working?Time passed since treatment started:
HOURS
DAYS
WEEKS
Initial effect
MONTHS
Full effect

Drug facts

Common BrandsCamzyos
Drug ClassCardiac myosin inhibitor
Controlled Substance ClassificationNot a controlled medication
Generic StatusNo lower-cost generic available
AvailabilityPrescription only
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Side effects of Camzyos (mavacamten)

The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.

Common Side Effects

  • Dizziness (27%)

Less Common Side Effects

  • Fainting

Camzyos (mavacamten) serious side effects

Contact your healthcare provider immediately if you experience any of the following.

  • Heart failure: trouble breathing, cough, wheezing, swelling in legs and ankles, fast or irregular heartbeat, tiredness, can't do much physical activity without exerting yourself

Source: DailyMed

The following Camzyos (mavacamten) side effects have also been reported

Side effects that you should report to your care team as soon as possible:

Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome):

  • Dizziness
  • Feeling faint or lightheaded
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Pros and cons of Camzyos (mavacamten)

Pros

Cons

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Pharmacist tips for Camzyos (mavacamten)

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  • Take Camzyos (mavacamten) once a day with or without food.
  • Swallow the Camzyos (mavacamten) capsule whole. Don't break it open or chew it.
  • If you forget to take Camzyos (mavacamten), take it as soon as possible before the end of the day. If you realize you forgot the next day, skip the missed dose. This is because you shouldn't take more than one dose on the same day. Take your next dose at your usual time.
  • Ask your prescriber how often to get your heart checked. As part of the Camzyos REMS program, your prescriber needs to check how well your heart is working often. This helps monitor for heart failure. If needed, your prescriber can lower your dose or stop treatment to keep you safe.
  • Keep taking Camzyos (mavacamten) as prescribed, even if you don't feel a difference at first. Remember, it can take weeks before you notice benefits from the medication. Your prescriber will adjust your dose based on how well it's working for you. And it could take some time to reach this optimal dose.
  • Camzyos (mavacamten) can make you dizzy. Sit down and rest until you feel better. It might be a good idea not to drive or do anything that could be dangerous until you know how the medication makes you feel. Tell your care team if you feel too dizzy and it's hard to go about your day.
  • Tell your prescriber and pharmacist about the medications you take or plan to take. This includes prescription medications, over-the-counter medications, vitamins, and herbal supplements. Camzyos (mavacamten) interacts with a lot of medications. Some interactions can make Camzyos (mavacamten) work less well or raise your risk of heart failure. Give your care team an updated medication list. They can check for dangerous drug interactions and make changes to keep you safe if needed.
  • If you can become pregnant, talk to your prescriber or gynecologist about birth control options. It's important to avoid getting pregnant because Camzyos (mavacamten) can cause serious harm to an unborn baby. Use birth control while taking this medication and for 4 months after your last dose. If you get pregnant, tell your healthcare team right away.
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Risks and warnings for Camzyos (mavacamten)

Camzyos (mavacamten) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.

Risk of heart failure

  • Risk factors: Heart rhythm problems | Serious infection | Taking other medications that can cause heart failure

Camzyos (mavacamten) helps your heart squeeze (contract) less. But as a consequence, it can put you at risk of heart failure or make it harder for your heart to pump blood.

Your risk of heart failure is higher if you have an irregular heartbeat (arrhythmia) or a serious infection. You should avoid Camzyos (mavacamten) if you take other medications that raise your risk of heart failure.

To make sure it's as safe as possible for you, this medication is only available through the Camzyos REMS program. You, as well as your prescriber and pharmacy, will need to register in the program. Your prescriber will talk to you about the risk of heart failure. They'll discuss steps to take to minimize the risk. The Camzyos REMS program also requires regular echocardiograms (echos) to check your heart function.

To check how well your heart is pumping, you'll need to get echocardiograms before and during treatment. The test measures the strength of your heart (called ejection fraction). If your heart isn't pumping as well as it should, your prescriber will lower the dose or have you stop treatment.

Tell your care team right away if you have worsening signs of heart failure. Look out for chest pain, trouble breathing, tiredness, weakness, and swelling in the hands and feet.

Drug interactions

Camzyos (mavacamten) can interact with a lot of medications. These medications can include prescription medications for seizures and antifungals. They can also include over-the-counter medications like omeprazole (Prilosec) and supplements like St. John's wort.

Some drug interactions can make Camzyos (mavacamten) break down faster in the body. This can make the heart medication not work as well for you. Other drug interactions can raise your risk of side effects from Camzyos (mavacamten). This includes putting you at higher risk of heart failure.

It's important to tell your prescriber and pharmacist about all the medications you take. Don't start any new ones without talking to them first. Share an updated medication list with them. Your care team can check that all your medications are safe to take together. They can adjust your treatment plan if needed to keep you safe.

Harm to an unborn baby

Animal studies show that Camzyos (mavacamten) can cause serious harm to an unborn baby if taken during pregnancy.

If you can become pregnant, your prescriber might double check that you're not pregnant before starting Camzyos (mavacamten). Check with a pregnancy test if they ask you to.

While taking Camzyos (mavacamten), use reliable birth control if you're having sex. Keep using birth control for 4 months after you stop Camzyos (mavacamten). This medication can interact with some hormonal birth control pills. It can make the birth control not work as well to prevent pregnancy. So, talk to your prescriber or gynecologist about a good birth control option for you. Ask them if you need to use a nonhormonal option like condoms as backup.

If you get pregnant while taking Camzyos (mavacamten) or within 4 months of stopping it, tell your healthcare team right away.

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Camzyos (mavacamten) dosage

Typical dosage for Camzyos (mavacamten)

The typical starting dose is 5 mg by mouth once a day.

Your prescriber will adjust the dose based on how well it's helping your symptoms. It also depends on your heart function and if you have side effects. Your prescriber will also adjust the dose if you also take other medications that interact with Camzyos (mavacamten).

The usual dosage is either 2.5 mg, 5 mg, 10 mg, or 15 mg once a day.

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Camzyos (mavacamten) contraindications

Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Camzyos (mavacamten) will not be safe for you to take.

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News about Camzyos (mavacamten)

References

Best studies we found

American Heart Association. (2025). Ejection fraction heart failure measurement.

Barrick, S. K., et al. (2021). Cardiac myosin contraction and mechanotransduction in health and disease. The Journal of Biological Chemistry.

Bristol Myers Squibb. (2025). Camzyos® REMS patient brochure.

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