CAMZYOS: Uses, Dosage & Side Effects
A first-in-class cardiac myosin inhibitor for the treatment of symptomatic obstructive hypertrophic cardiomyopathy (oHCM) in adults
CAMZYOS (mavacamten) is a first-in-class, selective, allosteric, reversible cardiac myosin inhibitor used to treat symptomatic obstructive hypertrophic cardiomyopathy (oHCM) in adults. Hypertrophic cardiomyopathy is a genetic heart condition in which the heart muscle becomes abnormally thick, making it harder for the heart to pump blood. In the obstructive form, the thickened muscle narrows the outflow tract from the left ventricle, impeding blood flow. CAMZYOS works at the fundamental level of the disease by reducing the excessive contraction of the heart muscle, thereby improving blood flow and relieving symptoms such as shortness of breath, chest pain, fatigue, and dizziness. It is taken as a once-daily oral capsule and requires regular echocardiographic monitoring throughout treatment.
Quick Facts: CAMZYOS
Key Takeaways
- CAMZYOS (mavacamten) is the first cardiac myosin inhibitor approved for symptomatic obstructive hypertrophic cardiomyopathy (oHCM), targeting the underlying disease mechanism at the sarcomere level rather than just managing symptoms.
- Regular echocardiographic monitoring is mandatory—before starting treatment, at weeks 4, 8, and 12, then every 3 to 6 months—to ensure the heart’s pumping function (ejection fraction) remains adequate.
- CAMZYOS must not be used during pregnancy due to potential harm to the unborn baby; women of childbearing potential must use effective contraception during treatment and for 6 months after stopping.
- Numerous drug interactions exist, particularly with strong CYP2C19 and CYP3A4 inhibitors (which are contraindicated) and CYP enzyme inducers that may reduce effectiveness; always inform your doctor about all medications you take.
- The most important side effect to monitor is systolic dysfunction (reduced heart pumping function), which can potentially lead to heart failure; dose adjustments are guided by echocardiography results.
What Is CAMZYOS and What Is It Used For?
CAMZYOS contains the active substance mavacamten, a revolutionary medication that represents a new therapeutic class known as cardiac myosin inhibitors. Mavacamten was specifically designed to address the fundamental molecular abnormality underlying hypertrophic cardiomyopathy (HCM)—excessive actin-myosin cross-bridge formation in the heart muscle. This first-in-class mechanism of action makes CAMZYOS fundamentally different from all previous pharmacological treatments for HCM, which managed symptoms without addressing the underlying pathophysiology.
Understanding Obstructive Hypertrophic Cardiomyopathy
Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease, affecting approximately 1 in 500 people worldwide, though many cases remain undiagnosed. The condition is caused by mutations in genes encoding sarcomeric proteins—the molecular machinery responsible for heart muscle contraction. These genetic mutations lead to structural and functional abnormalities in the heart muscle, including increased wall thickness (hypertrophy), increased stiffness, and impaired relaxation.
In the obstructive form of HCM (oHCM), which accounts for approximately two-thirds of all HCM cases, the thickened interventricular septum narrows the left ventricular outflow tract (LVOT). During systole (the contraction phase of the heartbeat), the combination of rapid blood flow through this narrowed passage and abnormal positioning of the mitral valve leaflet creates a dynamic obstruction that impedes blood flow from the heart to the rest of the body. This obstruction worsens with physical exertion, dehydration, and certain physiological states, leading to characteristic symptoms including shortness of breath (dyspnea), chest pain, fatigue, dizziness, lightheadedness, fainting (syncope), palpitations, and swelling of the ankles, feet, legs, abdomen, or neck veins.
The dynamic nature of LVOT obstruction in oHCM distinguishes it from fixed obstructions such as aortic stenosis. The degree of obstruction can vary significantly throughout the day and in response to various physiological triggers. At rest, some patients may have minimal obstruction, while during exercise or after meals, the gradient across the LVOT can increase dramatically. This variability explains why symptoms often fluctuate and why diagnosis can be challenging.
How CAMZYOS Works
Mavacamten works through a unique mechanism at the molecular level of the heart muscle. In a healthy heart, the protein myosin cycles between active and inactive (super-relaxed) states. In HCM, genetic mutations cause too many myosin molecules to be in the active state, resulting in excessive cross-bridge formation between actin and myosin filaments. This leads to hypercontractility (the heart squeezing too hard) and impaired relaxation (the heart not relaxing properly between beats).
CAMZYOS selectively and reversibly binds to cardiac myosin, stabilizing it in the super-relaxed state. By reducing the proportion of myosin molecules available for cross-bridge formation during each cardiac cycle, mavacamten decreases the excessive contractile force generated by the hypertrophied heart muscle. This reduction in contractility directly decreases the dynamic LVOT obstruction, improves diastolic filling (the heart’s ability to relax and fill with blood), and reduces intracardiac pressures. The result is improved blood flow out of the heart and meaningful relief of symptoms.
The landmark EXPLORER-HCM trial, a phase 3 randomized controlled trial published in The Lancet in 2020, demonstrated that mavacamten significantly improved exercise capacity, LVOT obstruction, symptom burden, and quality of life in patients with symptomatic oHCM compared with placebo. The VALOR-HCM trial subsequently showed that mavacamten could reduce the need for septal reduction therapy (surgical myectomy or alcohol septal ablation) in patients who were being considered for these invasive procedures.
CAMZYOS is the first medication specifically designed to target the underlying molecular mechanism of hypertrophic cardiomyopathy. Before its approval, treatment options for oHCM were limited to beta-blockers, non-dihydropyridine calcium channel blockers (such as verapamil), and disopyramide—all of which were developed for other conditions and used off-label or as symptomatic therapy. For patients with inadequate symptom control on these medications, the only remaining options were invasive septal reduction procedures (surgical myectomy or alcohol septal ablation). CAMZYOS has fundamentally expanded the treatment paradigm for this condition.
What Should You Know Before Taking CAMZYOS?
Contraindications
There are specific situations in which CAMZYOS must not be used. Understanding these absolute contraindications is essential for safe treatment.
- Hypersensitivity: Do not take CAMZYOS if you are allergic to mavacamten or any of the other ingredients, including colloidal hydrated silica, mannitol (E421), hypromellose (E464), croscarmellose sodium (E468), magnesium stearate, gelatin, titanium dioxide (E171), iron oxides (E172), shellac (E904), propylene glycol (E1520), and potassium hydroxide (E525).
- Pregnancy: CAMZYOS is contraindicated in pregnancy and in women of childbearing potential not using effective contraception. Based on its mechanism of action, mavacamten may cause fetal harm by reducing cardiac contractility in the developing fetus.
- Strong CYP inhibitors: Do not take CAMZYOS with medications that significantly increase mavacamten blood levels. Specifically contraindicated are: oral antifungals (itraconazole, ketoconazole, posaconazole, voriconazole), certain antibiotics (clarithromycin), certain HIV treatments (cobicistat, ritonavir), and certain cancer drugs (ceritinib, idelalisib, tucatinib).
Warnings and Precautions
CAMZYOS can reduce the heart’s ejection fraction (pumping function) below safe levels, potentially leading to systolic dysfunction and heart failure. This is a serious and potentially life-threatening complication. Contact your doctor immediately if you experience new or worsening shortness of breath, chest pain, fatigue, palpitations (forceful, rapid, or irregular heartbeats), or swollen legs. Regular echocardiographic monitoring is mandatory to detect and manage this risk.
Before and during treatment with CAMZYOS, your doctor will perform several important assessments and monitoring procedures:
- Echocardiographic monitoring: Your doctor will assess your heart function using echocardiography (an ultrasound examination that creates images of the heart) before your first dose and regularly during treatment. Echocardiograms are scheduled before starting treatment, at weeks 4, 8, and 12 for dose titration, and then every 3 to 6 months during maintenance therapy. If your dose is changed at any point, a follow-up echocardiogram is performed 4 weeks later to confirm the dose is safe and effective.
- CYP2C19 metabolizer testing: Your doctor may perform a genetic test to determine how your body metabolizes mavacamten. The CYP2C19 enzyme is primarily responsible for breaking down the drug, and genetic variations can significantly affect drug levels. Poor metabolizers have a much longer drug half-life (up to 23 days versus 6–9 days in normal metabolizers) and require lower starting doses and more careful titration.
- Pregnancy testing: If you are a woman of childbearing potential, your doctor will perform a pregnancy test before starting CAMZYOS. You will receive a patient card explaining why you must not become pregnant while taking this medication.
- Infections and arrhythmias: If you develop a serious infection or irregular heart rhythm (arrhythmia) during treatment, the risk of developing heart failure may increase. Your doctor may need to perform additional heart function tests, interrupt treatment, or adjust the dose.
Pregnancy and Breastfeeding
CAMZYOS must not be taken during pregnancy. Based on its mechanism of action as a cardiac myosin inhibitor, mavacamten may cause harm to the developing fetus by reducing cardiac contractility during critical stages of fetal heart development. If you are a woman who can become pregnant, your doctor will inform you about this risk and require a pregnancy test before starting treatment.
You must use effective contraception during treatment with CAMZYOS and for at least 6 months after stopping the medication. The extended period after discontinuation is necessary because mavacamten has a long half-life and its effects may persist for weeks after the last dose. Your doctor will provide you with a patient card explaining the pregnancy prevention requirements.
If you become pregnant while taking CAMZYOS, you must immediately inform your doctor. Treatment will be discontinued, and your doctor will discuss the next steps with you to ensure your heart condition is managed appropriately during the transition.
It is not known whether mavacamten or its metabolites are excreted in human breast milk. Because of the potential risk to the nursing infant, breastfeeding is not recommended during treatment with CAMZYOS.
Children and Adolescents
CAMZYOS has not been studied in children and adolescents under 18 years of age. The safety and efficacy of mavacamten have not been established in this age group, and the medication should not be given to patients under 18. Pediatric HCM represents a distinct clinical entity with different genetic and phenotypic characteristics, and the effects of cardiac myosin inhibition during growth and development have not been evaluated.
Driving and Operating Machinery
Mavacamten may have a minor effect on your ability to drive and use machines. Dizziness is one of the most common side effects of CAMZYOS. If you feel dizzy while taking this medication, do not drive vehicles, cycle, or use tools or machinery until the dizziness has resolved. Discuss with your doctor if you have concerns about your ability to perform these activities safely during treatment.
Important Information About Ingredients
CAMZYOS contains less than 1 mmol (23 mg) of sodium per capsule, meaning it is essentially sodium-free. This is relevant for patients on sodium-restricted diets. The capsule shells contain gelatin, titanium dioxide (E171), and various iron oxides (E172) as colorants, with the cap color varying by strength: light purple for 2.5 mg, yellow for 5 mg, pink for 10 mg, and grey for 15 mg.
How Does CAMZYOS Interact with Other Drugs?
Mavacamten is extensively metabolized by cytochrome P450 enzymes in the liver, primarily by CYP2C19, with additional contributions from CYP3A4 and CYP2C9. Other medications which inhibit or induce these enzymes can significantly alter the blood levels of mavacamten, potentially leading to either dangerous increases in drug exposure (with inhibitors) or reduced therapeutic effect (with inducers). Because the therapeutic window of mavacamten is relatively narrow, drug interactions are a particularly important safety consideration.
Before starting CAMZYOS, you must tell your doctor about every medication you are taking, have recently taken, or plan to take. This includes prescription medications, over-the-counter drugs, herbal supplements, and dietary products. You should never start, stop, or change the dose of any medication without first discussing it with your doctor, as even temporary changes can affect mavacamten levels unpredictably.
Major Interactions (Contraindicated)
| Interacting Drug | Effect | Clinical Significance |
|---|---|---|
| Itraconazole, ketoconazole, posaconazole, voriconazole (oral antifungals) | Markedly increased mavacamten levels via CYP3A4/CYP2C19 inhibition | Contraindicated – risk of severe cardiac depression |
| Clarithromycin (macrolide antibiotic) | Significantly increased mavacamten levels via CYP3A4 inhibition | Contraindicated – use alternative antibiotic |
| Ritonavir, cobicistat (HIV medications) | Strong CYP3A4 inhibition leading to dangerously elevated mavacamten levels | Contraindicated – do not combine |
| Ceritinib, idelalisib, tucatinib (anticancer agents) | Strong CYP3A4/CYP2C19 inhibition increasing mavacamten exposure | Contraindicated – do not combine |
Significant Interactions (Require Monitoring)
| Interacting Drug | Effect | Clinical Significance |
|---|---|---|
| Fluconazole (antifungal) | Moderate CYP2C19 inhibition; increased mavacamten levels | Close monitoring required; dose adjustment may be needed |
| Fluoxetine, fluvoxamine, citalopram (antidepressants) | CYP2C19 inhibition; moderately increased mavacamten levels | Close monitoring required; inform your doctor before starting or stopping |
| Omeprazole, esomeprazole, pantoprazole, cimetidine (acid reducers) | CYP2C19 inhibition; may increase mavacamten exposure | Close monitoring recommended; dose adjustment possible |
| Verapamil, diltiazem (calcium channel blockers) | Additive negative inotropic effect; also possible CYP3A4 inhibition | Close monitoring required; combined use may increase risk of heart failure |
| Disopyramide (antiarrhythmic) | Additive negative inotropic effect | Close monitoring recommended; combined use needs careful assessment |
| Rifampicin (anti-tuberculosis antibiotic) | Strong CYP3A4 and CYP2C19 induction; substantially reduced mavacamten levels | Avoid combination; therapeutic effect may be lost |
| Carbamazepine, phenytoin, phenobarbital, primidone (antiepileptics) | CYP enzyme induction; reduced mavacamten levels | Avoid combination; efficacy may be significantly diminished |
| St. John’s Wort (herbal supplement) | CYP3A4 and CYP2C19 induction; reduced mavacamten levels | Avoid concurrent use; may reduce drug effectiveness |
| Grapefruit juice | CYP3A4 inhibition; may increase mavacamten levels | Use caution; avoid excessive grapefruit juice consumption |
Beta-blockers are commonly used in combination with CAMZYOS for the management of oHCM. Clinical trials included patients receiving background beta-blocker therapy. While there is no direct pharmacokinetic interaction, the combined negative inotropic effects should be monitored. Your cardiologist will carefully balance these medications to achieve optimal symptom control without excessive cardiac depression.
Do not take any of the medications listed above on an irregular or as-needed basis while on CAMZYOS, as unpredictable changes in mavacamten levels can occur. Even a short course of a contraindicated drug can cause dangerous accumulation due to mavacamten’s long half-life. Always consult your doctor before starting or stopping any medication, including over-the-counter products and supplements.
What Is the Correct Dosage of CAMZYOS?
CAMZYOS should always be taken exactly as prescribed by your doctor. The dosing regimen is individualized based on your heart’s response to treatment, assessed through serial echocardiographic examinations. This personalized titration approach is essential because the relationship between dose, drug levels, and cardiac effects varies significantly between patients, particularly due to genetic differences in CYP2C19 metabolism.
Adults
Starting Dose
Standard starting dose: 2.5 mg or 5 mg once daily, taken orally
Determination: Your doctor may perform a CYP2C19 genotype test to guide the initial dose. Poor metabolizers may start at a lower dose due to higher expected drug levels. Patients with liver impairment may also require a lower starting dose.
Administration: Swallow the capsule whole with a glass of water at approximately the same time each day. The capsule may be taken with or without food.
Dose Titration
Monitoring schedule: Echocardiograms are performed at weeks 4, 8, and 12 to assess your heart’s response.
Dose adjustment: Based on echocardiographic findings (particularly left ventricular ejection fraction and LVOT gradient), your doctor may increase, decrease, or temporarily discontinue the dose.
Available doses: 2.5 mg, 5 mg, 10 mg, or 15 mg once daily. The maximum dose is 15 mg once daily.
Maintenance Therapy
Ongoing monitoring: After the initial titration period, routine echocardiograms are performed every 3 to 6 months.
Dose changes: If your doctor adjusts the dose at any time during maintenance therapy, a follow-up echocardiogram is performed 4 weeks after the dose change.
Duration: CAMZYOS is intended for long-term use. Do not stop taking it without consulting your doctor.
| Phase | Dose Range | Monitoring | Notes |
|---|---|---|---|
| Initiation | 2.5–5 mg once daily | Baseline echocardiogram | CYP2C19 genotype may guide starting dose |
| Titration (weeks 4–12) | 2.5–15 mg once daily | Echocardiogram at weeks 4, 8, 12 | Dose adjusted based on LVEF and LVOT gradient |
| Maintenance | 2.5–15 mg once daily | Echocardiogram every 3–6 months | Any dose change requires follow-up echo at 4 weeks |
| Liver impairment | Lower starting dose | Enhanced monitoring | Discuss with your doctor; dose may need reduction |
Children and Adolescents
CAMZYOS is not approved for use in children and adolescents under 18 years of age. The safety and efficacy of mavacamten have not been established in this population. Pediatric hypertrophic cardiomyopathy may have different characteristics compared with adult-onset disease, and the effects of cardiac myosin inhibition during growth and cardiac development are unknown.
Elderly Patients
No specific dose adjustment is required for elderly patients based on age alone. However, older adults are more likely to have concurrent medical conditions and take multiple medications, which may affect how CAMZYOS is metabolized. Your doctor will carefully consider potential drug interactions and may opt for a more conservative dose titration approach. The same echocardiographic monitoring schedule applies regardless of age.
Missed Dose
If you forget to take CAMZYOS at your usual time, take your dose as soon as you remember, provided it is still the same day. Take your next dose at the usual time the following day. Do not take a double dose to make up for a missed capsule. Because mavacamten has a long half-life (several days), a single missed dose is unlikely to cause a sudden change in your clinical status, but consistent daily dosing is important for maintaining stable drug levels.
Overdose
If you have taken more capsules than you should, contact your doctor or go to the nearest hospital emergency department immediately, especially if you have taken 3 to 5 times the recommended dose. If possible, bring the medication package with you. An overdose of mavacamten could lead to excessive reduction of the heart’s contractile function, potentially causing severe hypotension, cardiogenic shock, or heart failure. Due to the long half-life, the effects of an overdose may be prolonged and require extended medical monitoring.
Stopping CAMZYOS
Do not stop taking CAMZYOS unless your doctor tells you to do so. If you wish to stop, discuss it with your doctor first. Abrupt discontinuation may lead to a rebound in LVOT obstruction and worsening of symptoms. Your doctor will advise you on how to safely discontinue the medication and may adjust other HCM therapies accordingly.
What Are the Side Effects of CAMZYOS?
Like all medicines, CAMZYOS can cause side effects, although not everyone experiences them. The side effect profile of mavacamten reflects its mechanism of action—by reducing cardiac contractility, there is an inherent risk of reducing heart function too much. This is why regular echocardiographic monitoring is essential and why dose titration is carefully guided by imaging results.
In clinical trials (EXPLORER-HCM and VALOR-HCM), mavacamten was generally well tolerated. Most side effects were mild to moderate in severity and manageable with dose adjustments. The overall discontinuation rate due to adverse events was low compared with many other cardiovascular medications.
Serious Side Effects
Contact your doctor immediately if you experience any of the following symptoms: new or worsening shortness of breath, chest pain, fatigue, palpitations (forceful heartbeats that may be rapid or irregular), or swollen legs. These may be signs and symptoms of systolic dysfunction, which may be life-threatening and lead to heart failure. This is a common side effect (affecting up to 1 in 10 patients).
Side Effects by Frequency
Very Common
May affect more than 1 in 10 people
- Dizziness – feeling lightheaded or unsteady, particularly when standing up; typically mild to moderate and may decrease over time as the body adjusts to the medication
- Dyspnea (breathing difficulties) – shortness of breath, which may occur during physical exertion; any new or worsening breathlessness should be reported to distinguish from the underlying condition
Common
May affect up to 1 in 10 people
- Syncope (fainting) – temporary loss of consciousness, usually caused by a brief drop in blood flow to the brain; inform your doctor as a dose adjustment may be needed
- Systolic dysfunction – reduced ejection fraction detected on echocardiography; your doctor monitors for this at each follow-up visit and will adjust your dose accordingly
The frequency and severity of side effects can be influenced by your CYP2C19 metabolizer status (poor metabolizers may experience higher drug levels and more pronounced effects), the presence of concomitant medications that interact with mavacamten, and your baseline cardiac function. Your doctor takes all of these factors into account when determining your optimal dose.
It is important to distinguish between side effects of CAMZYOS and symptoms of the underlying condition (oHCM). Both can cause dizziness, shortness of breath, and fainting. If you notice any change in the pattern or severity of your symptoms, report it to your doctor so that appropriate evaluation can be performed, including echocardiography if needed.
Reporting suspected side effects after a medicine has been authorized is important. It allows ongoing monitoring of the medicine’s benefit-risk balance. Healthcare professionals and patients are encouraged to report suspected adverse reactions to their national pharmacovigilance authority (e.g., the FDA MedWatch program in the United States, the Yellow Card Scheme in the United Kingdom, or the EMA EudraVigilance system in the European Union).
How Should You Store CAMZYOS?
Proper storage of CAMZYOS is straightforward but important for maintaining the medication’s effectiveness and safety throughout its shelf life.
- Temperature: No special temperature storage requirements. Store at room temperature.
- Children: Keep CAMZYOS out of sight and reach of children at all times.
- Expiry date: Do not use CAMZYOS after the expiry date stated on the blister pack and carton after “EXP.” The expiry date refers to the last day of that month.
- Packaging: CAMZYOS hard capsules are supplied in aluminum foil blisters containing 14 capsules. Pack sizes of 14, 28, or 98 hard capsules are available, though not all sizes may be marketed in every country.
- Disposal: Do not throw unused medicines in household waste or down the drain. Return any unused or expired capsules to your pharmacist for safe disposal to help protect the environment.
What Does CAMZYOS Contain?
Each CAMZYOS hard capsule contains one of four strengths of the active substance mavacamten: 2.5 mg, 5 mg, 10 mg, or 15 mg. Your doctor will prescribe the appropriate strength for your treatment phase.
Active Ingredient
Mavacamten is a small-molecule, selective, allosteric, reversible inhibitor of cardiac myosin ATPase. It has the molecular formula C15H19N3O2 and a molecular weight of approximately 273.33 g/mol. Mavacamten was originally identified as MYK-461 during its development by MyoKardia (now part of Bristol-Myers Squibb).
Inactive Ingredients
The capsule contents include: colloidal hydrated silica (a flow agent), mannitol (E421, a filler), hypromellose (E464, a binder), croscarmellose sodium (E468, a disintegrant), and magnesium stearate (a lubricant). The capsule shells are made of gelatin with titanium dioxide (E171) as an opacifier and various iron oxides (E172) for coloring. The printing ink contains shellac (E904), black iron oxide (E172), propylene glycol (E1520), concentrated ammonia solution (E527), and potassium hydroxide (E525).
Capsule Appearance by Strength
| Strength | Cap Color | Body Color | Markings |
|---|---|---|---|
| 2.5 mg | Light purple, opaque | White, opaque | “2.5 mg” on cap, “Mava” on body (black ink) |
| 5 mg | Yellow, opaque | White, opaque | “5 mg” on cap, “Mava” on body (black ink) |
| 10 mg | Pink, opaque | White, opaque | “10 mg” on cap, “Mava” on body (black ink) |
| 15 mg | Grey, opaque | White, opaque | “15 mg” on cap, “Mava” on body (black ink) |
All capsules are approximately 18.0 mm in length. If your capsules look different from what is described above, do not take them and consult your pharmacist.
Frequently Asked Questions About CAMZYOS
CAMZYOS (mavacamten) is used to treat symptomatic obstructive hypertrophic cardiomyopathy (oHCM) in adults. It is the first cardiac myosin inhibitor approved for this condition. Obstructive HCM is a genetic heart disease in which the heart muscle becomes abnormally thick and blocks blood flow out of the left ventricle. CAMZYOS works by reducing the excessive contraction of the heart muscle, which directly addresses the underlying cause of obstruction and improves symptoms such as shortness of breath, chest pain, fatigue, and dizziness.
Unlike beta-blockers and verapamil, which were developed for other conditions and manage symptoms indirectly, CAMZYOS was specifically designed to target the molecular cause of HCM. It acts directly on the sarcomere by inhibiting cardiac myosin, reducing the excessive cross-bridge formation that causes hypercontractility. Beta-blockers slow the heart rate and reduce overall cardiac workload, while verapamil relaxes blood vessels and slows heart conduction. CAMZYOS uniquely addresses the fundamental hypercontractility that drives LVOT obstruction, making it a disease-modifying therapy rather than just symptomatic treatment.
Regular echocardiograms are essential because CAMZYOS works by reducing the heart’s contractile force. If the effect is too strong, it can reduce the ejection fraction to dangerously low levels, potentially causing heart failure. The echocardiograms allow your doctor to precisely measure your ejection fraction and LVOT gradient, and to adjust your dose accordingly. This imaging-guided approach ensures you receive the optimal dose that improves symptoms without compromising cardiac function.
Many patients take CAMZYOS alongside other heart medications, particularly beta-blockers, which were commonly used in the clinical trials. However, several medications require caution or are contraindicated. Calcium channel blockers like verapamil and diltiazem can have additive effects on reducing cardiac contractility and require close monitoring. Disopyramide also has additive negative inotropic effects. Strong inhibitors of CYP2C19 and CYP3A4 enzymes are contraindicated. Always inform your cardiologist about all medications you take so that appropriate monitoring and dose adjustments can be made.
Yes, clinical evidence supports this. The VALOR-HCM trial specifically studied patients with symptomatic oHCM who met guidelines criteria for septal reduction therapy. The trial showed that treatment with mavacamten significantly reduced the proportion of patients who still met criteria for or chose to proceed with these invasive procedures. This suggests that CAMZYOS may allow some patients to avoid surgery by achieving adequate symptom control and reduction of LVOT obstruction through medical therapy alone. However, the decision is always individualized between you and your cardiologist.
Dizziness is one of the most common side effects of CAMZYOS and is usually mild to moderate. If you experience dizziness, sit or lie down until it passes, stand up slowly from sitting or lying positions, stay well hydrated, and avoid driving or operating machinery. If dizziness is persistent, severe, or accompanied by other symptoms such as chest pain, shortness of breath, or fainting, contact your doctor promptly as your dose may need adjustment.
References
- European Medicines Agency (EMA). CAMZYOS (mavacamten) – Summary of Product Characteristics. Last updated 2025. Available at: www.ema.europa.eu
- U.S. Food and Drug Administration (FDA). CAMZYOS (mavacamten) – Prescribing Information. Bristol-Myers Squibb. Revised 2024. Available at: www.accessdata.fda.gov
- Olivotto I, Oreziak A, Barriales-Villa R, et al. Mavacamten for treatment of symptomatic obstructive hypertrophic cardiomyopathy (EXPLORER-HCM): a randomised, double-blind, placebo-controlled, phase 3 trial. The Lancet. 2020;396(10253):759-769. doi:10.1016/S0140-6736(20)31792-X
- Desai MY, Owens A, Geske JB, et al. Myosin Inhibition in Patients With Obstructive Hypertrophic Cardiomyopathy Referred for Septal Reduction Therapy (VALOR-HCM). Journal of the American College of Cardiology. 2023;82(2):95-109. doi:10.1016/j.jacc.2023.04.042
- Arbelo E, Protonotarios A, Gimeno JR, et al. 2023 ESC Guidelines for the management of cardiomyopathies. European Heart Journal. 2023;44(37):3503-3626. doi:10.1093/eurheartj/ehad194
- Ommen SR, Mital S, Burke MA, et al. 2020 AHA/ACC Guideline for the Diagnosis and Treatment of Patients With Hypertrophic Cardiomyopathy. Circulation. 2020;142(25):e558-e631. doi:10.1161/CIR.0000000000000937
- Green EM, Wakimoto H, Anderson RL, et al. A small-molecule inhibitor of sarcomere contractility suppresses hypertrophic cardiomyopathy in mice. Science. 2016;351(6273):617-621. doi:10.1126/science.aad3456
- Ho CY, Mealiffe ME, Bach RG, et al. Evaluation of Mavacamten in Symptomatic Patients With Nonobstructive Hypertrophic Cardiomyopathy. Journal of the American College of Cardiology. 2020;75(21):2649-2660. doi:10.1016/j.jacc.2020.03.064
- World Health Organization (WHO). Model List of Essential Medicines. 23rd edition. Geneva: WHO; 2023. Available at: www.who.int
- British National Formulary (BNF). Mavacamten. National Institute for Health and Care Excellence (NICE). Available at: bnf.nice.org.uk
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Evidence standard: All medical information is based on Level 1A evidence (systematic reviews and randomized controlled trials) where available, following the GRADE framework for evaluating certainty of evidence. This article was last reviewed on .