Ranolazine-induced myopathy in a patient on chronic statin therapy

Area of Science:

• Neurology
• Pharmacology
• Muscle Biology

Background:

• Chronic statin therapy is common for cardiovascular disease prevention.
• Ranolazine is an antianginal medication with known drug interaction potential.
• Drug-induced myopathies are a significant concern in clinical practice.

Observation:

• A patient on chronic statin therapy developed proximal muscle weakness.
• Clinical presentation included elevated creatine kinase (1875 U/L) and myopathic changes on electromyography.
• Magnetic resonance imaging revealed muscle edema, indicative of myositis.

Findings:

• Symptoms emerged within a week of initiating ranolazine.
• Discontinuation of ranolazine led to rapid clinical improvement.
• Ranolazine's inhibition of CYP3A4 may increase statin metabolism, potentially leading to myotoxicity.

Implications:

• This case suggests ranolazine can induce a myoncecrotic myopathy, particularly when co-administered with statins.
• Clinicians should be vigilant for myopathy in patients starting ranolazine, especially those on statin therapy.
• Understanding drug-drug interactions is crucial for preventing adverse events like drug-induced myopathies.