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Mavacamten may cause heart failure. Tell your doctor if you have or have ever had heart failure or told you had a low ejection fraction (how well your left ventricle pumps blood). Tell your doctor and pharmacist what medications you are taking before or during treatment with mavacamten including nonprescription medications such as St John's Wort, omeprazole, esomeprazole, or cimetidine. If you experience any of the following symptoms, call your doctor immediately or get medical treatment: shortness of breath, chest pain, fatigue, swelling in your leg, racing sensation in your heart, rapid weight gain.

Keep all appointments with your doctor. Your doctor will order an echocardiogram before starting and during treatment with mavacamten.

Your doctor or pharmacist will give you the manufacturer's patient information sheet (Medication Guide) when you begin treatment with mavacamten and each time you refill your prescription. Read the information carefully and ask your doctor or pharmacist if you have any questions. You can also visit the Food and Drug Administration (FDA) website ( to obtain the Medication Guide or go to

Talk to your doctor about the risk(s) of taking mavacamten.

Because of the risk of heart failure, a program called CAMZYOS Risk Evaluation and Mitigation Strategy (CAMZYOS REMS) has been set up to make sure that appropriate monitoring for heart failure is occurring during treatment with mavacamten. Your doctor will enroll you in CAMZYOS REMS and you will be required to use a special pharmacy to get mavacamten.

Why is this medication prescribed?

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.

How should this medicine be used?

Mavacamten comes as a capsule to take by mouth. It is usually taken with or without food once a day. Take mavacamten at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take mavacamten exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the tablets/capsules whole; do not split, chew, or crush them.

Your doctor will probably start you on a low dose of mavacamten and gradually decrease or increase your dose depending on your response to the medication and how you are feeling.

Mavacamten controls symptomatic obstructive hypertrophic cardiomyopathy but does not cure it. Continue to take mavacamten even if you feel well. Do not stop taking mavacamten without talking to your doctor.

Other uses for this medicine

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

What special precautions should I follow?

Before taking mavacamten,

  • tell your doctor and pharmacist if you are allergic to mavacamten, any other medications, or any of the ingredients in mavacamten capsules. Ask your pharmacist or check the Medication Guide for a list of the ingredients.
  • Some medications should not be taken with mavacamten while others may require a dose change or extra monitoring while taking mavacamten. Make sure you have discussed any medications you are currently taking or plan to take before starting mavacamten with your doctor and pharmacist. Before starting, stopping, or changing any medications while taking mavacamten, please get the advice of your doctor or pharmacist. Make sure you tell your doctor or pharmacist about all vitamins, nutritional supplements, and herbal products in addition to prescription and nonprescription medications.
  • You should know that mavacamten may decrease the effectiveness of hormonal contraceptives (birth control pills, patches, rings, and injections). You will need to use another method of contraception to prevent pregnancy while taking mavacamten, such as an intrauterine device or condom, and for 4 months after stopping mavacamten. Talk to your doctor about other ways to prevent pregnancy while you are taking this medication.
  • tell your doctor if you have or have ever had an infection or an arrhythmia (problem with rate or rhythm of your heart).
  • Mavacamten may harm your unborn baby. Tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking mavacamten, call your doctor immediately. If you are a female, your doctor will give you a pregnancy test before you start mavacamten. You should use an effective birth control such as condoms or an intrauterine device during treatment with mavacamten and for 4 months after.

What special dietary instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What should I do if I forget a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take two doses in one day to make up for a missed one.

What side effects can this medication cause?

Mavacamten may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • dizziness
  • fainting

Some side effects can be serious. If you experience any of those listed in the IMPORTANT WARNING section, call your doctor immediately or get emergency medical treatment.

Mavacamten may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online ( or by phone (1-800-332-1088).

What should I know about storage and disposal of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach.

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website ( for more information if you do not have access to a take-back program.

In case of emergency/overdose

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

What other information should I know?

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

Brand names

  • Camzyos®
Last Revised - 07/15/2022