Can a patient with cardiomyopathy (disease of the heart muscle) take hydroxychloroquine?

Hydroxychloroquine Use in Patients with Cardiomyopathy

Hydroxychloroquine is contraindicated in patients with cardiomyopathy due to the risk of fatal cardiotoxicity, including worsening heart failure and potentially life-threatening arrhythmias. 1

Cardiac Risks of Hydroxychloroquine

Hydroxychloroquine carries significant cardiac risks that make it unsuitable for patients with pre-existing cardiomyopathy:

• Direct cardiotoxicity: Hydroxychloroquine can cause fatal and life-threatening cardiotoxicity, including worsening of cardiomyopathy 1
• Ventricular arrhythmias: The medication has potential to prolong the QT interval, increasing risk of ventricular arrhythmias including torsades de pointes 1, 2
• Conduction abnormalities: Patients may develop atrioventricular blocks and bundle branch blocks 1
• Structural changes: Hydroxychloroquine can cause ventricular hypertrophy and pulmonary hypertension 1

FDA Contraindications

The FDA specifically warns against hydroxychloroquine administration in patients with:

• Cardiac disease including heart failure
• History of myocardial infarction
• Proarrhythmic conditions (bradycardia <50 bpm)
• History of ventricular dysrhythmias
• Uncorrected electrolyte abnormalities 1

Mechanism of Cardiac Toxicity

Hydroxychloroquine-induced cardiomyopathy occurs through:

• Development of phospholipidosis in cardiac tissue
• Lysosomal dysfunction leading to an acquired lysosomal storage disorder
• Progressive damage to cardiac muscle cells 3, 4

Alternative Treatments

For patients with cardiomyopathy who require treatment for conditions typically managed with hydroxychloroquine:

• Consider alternative immunomodulatory therapies such as corticosteroids, azathioprine, or cyclophosphamide 5
• For rheumatologic conditions, consult with rheumatology for alternative disease-modifying agents

Special Considerations

If hydroxychloroquine is deemed absolutely necessary despite cardiomyopathy (which would be extremely rare):

• Extensive cardiac monitoring would be required including:
  • Baseline and regular ECGs
  • Echocardiography to monitor ventricular function
  • Electrolyte monitoring and correction 2, 5
• Immediate discontinuation at first sign of worsening cardiac function 4

Common Pitfalls to Avoid

• Overlooking early signs of toxicity: Symptoms of worsening heart failure or new arrhythmias should prompt immediate medication discontinuation
• Inadequate monitoring: If hydroxychloroquine must be used in patients with mild cardiac disease, regular cardiac monitoring is essential
• Drug interactions: Avoid concurrent use of other QT-prolonging medications 2
• Exceeding recommended dosage: Never exceed 5 mg/kg/day based on actual body weight 5, 1

In conclusion, the evidence strongly indicates that hydroxychloroquine should be avoided in patients with cardiomyopathy due to the significant risk of worsening cardiac function and potentially fatal arrhythmias.