Home Drug Guide Mavacamten

Drug Guide

Generic Name

Mavacamten

Brand Names Camzyos

Classification

Therapeutic: Cardiovascular agent

Pharmacological: Myosin inhibitor

FDA Approved Indications

  • Treatment of symptomatic New York Heart Association (NYHA) class II-III obstructive hypertrophic cardiomyopathy (HCM) to improve functional capacity and symptoms

Mechanism of Action

Mavacamten is a selective allosteric inhibitor of cardiac myosin. It reduces excessive myosin-actin cross-bridge formation, decreasing hypercontractility of the myocardium, thereby alleviating left ventricular outflow tract obstruction and related symptoms in HCM.

Dosage and Administration

Adult: Initial dose of 5 mg orally once daily. Dose adjustments are based on clinical response and left ventricular ejection fraction (LVEF). The maximum dose is 15 mg daily.

Pediatric: Not approved for pediatric use.

Geriatric: Use with caution; monitor closely due to potential for increased sensitivity.

Renal Impairment: No specific adjustment recommended; however, renal function should be monitored.

Hepatic Impairment: Use with caution; initiate at lower doses due to hepatic metabolism.

Pharmacokinetics

Absorption: Rapidly absorbed after oral administration; food does not significantly affect absorption.

Distribution: Highly plasma protein-bound (~97%), primarily to albumin.

Metabolism: Primarily metabolized by hepatic CYP2C19 and CYP3A4 enzymes.

Excretion: Metabolites eliminated mainly via feces; minimal renal excretion.

Half Life: Approximately 46 hours, allowing once-daily dosing.

Contraindications

  • Severe hepatic impairment
  • Known hypersensitivity to mavacamten

Precautions

  • Monitor LVEF regularly; avoid in patients with baseline LVEF <50%
  • Use with caution in patients with impaired hepatic function
  • Potential for hypotension and heart failure exacerbation

Adverse Reactions - Common

  • Headache (Common)
  • Decreased LVEF (Common)
  • Fatigue (Common)

Adverse Reactions - Serious

  • Heart failure (Uncommon)
  • Arrhythmias (Uncommon)
  • Hypotension (Uncommon)

Drug-Drug Interactions

  • CYP2C19 inhibitors (e.g., omeprazole, fluoxetine) may increase mavacamten levels
  • CYP3A4 inhibitors (e.g., ketoconazole) may increase levels
  • CYP2C19 inducers may decrease efficacy

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor LVEF before and during treatment. Assess for symptoms of heart failure. Check hepatic function periodically.

Diagnoses:

  • Risk for decreased cardiac output
  • Risk for injury related to hypotension

Implementation: Administer as prescribed, monitor cardiac function, and counsel on recognizing adverse effects.

Evaluation: Evaluate improvement in symptoms and maintain LVEF within safe limits.

Patient/Family Teaching

  • Take mavacamten exactly as prescribed.
  • Report symptoms such as dizziness, fainting, shortness of breath, or swelling.
  • Attend regular follow-up appointments for monitoring of cardiac function.
  • Inform healthcare providers of all medications being taken.

Special Considerations

Black Box Warnings:

  • Reduced LVEF: Mavacamten can cause reduction in LVEF; monitor closely.

Genetic Factors: CYP2C19 genotype may affect drug metabolism; poor metabolizers may have increased exposure.

Lab Test Interference: May affect assessment of cardiac function; interpret with caution.

Overdose Management

Signs/Symptoms: Severe hypotension, bradycardia, symptoms of heart failure.

Treatment: Discontinue drug; provide supportive care, monitor cardiac status, and manage symptoms accordingly.

Storage and Handling

Storage: Store at room temperature between 20°C to 25°C (68°F to 77°F).

Stability: Stable up to the expiration date when stored properly.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.