Statin Use in Myasthenia Gravis: Safety and Efficacy Considerations

Introduction to Statin Therapy in Myasthenia Gravis

The American College of Cardiology recommends obtaining baseline creatine kinase (CK) levels to distinguish future statin-induced myopathy from myasthenia gravis (MG) fluctuations in patients with MG, with a strength of evidence level of B (moderate) 1, 2
The American College of Cardiology suggests documenting baseline MG symptom severity, particularly oculobulbar symptoms, for comparison, with a strength of evidence level of C (low) 1, 3
The American College of Cardiology advises checking thyroid-stimulating hormone (TSH) levels as hypothyroidism predisposes to myopathy and can confound the clinical picture, with a strength of evidence level of B (moderate) 1, 3

The American College of Cardiology recommends starting with the lowest effective dose to achieve lipid targets, with a strength of evidence level of A (high) 3
The American College of Cardiology suggests considering pravastatin or fluvastatin as they have less CYP3A4 interaction and may have lower risk profiles, with a strength of evidence level of B (moderate) 4
The American College of Cardiology advises avoiding high-intensity statins initially (e.g., atorvastatin 80 mg, rosuvastatin 40 mg) as myopathy risk increases with dose, with a strength of evidence level of A (high) 4, 3
The American College of Cardiology recommends evaluating patients at 2, 4, 8, and 16 weeks after initiation, with a strength of evidence level of B (moderate) 5
The American College of Cardiology suggests measuring CK if any muscle symptoms develop and comparing to baseline, with a strength of evidence level of B (moderate) 1, 2

The American College of Cardiology recommends stopping the statin if new or worsening oculobulbar weakness, CK >10 times upper limit of normal with muscle symptoms, progressive muscle weakness, or rhabdomyolysis (CK >10× ULN with renal injury) occur, with a strength of evidence level of A (high) 1, 3, 6
The American College of Cardiology advises against re-challenging with the same statin if MG worsening occurred, with a strength of evidence level of B (moderate) 3

The American College of Cardiology identifies advanced age (>80 years), small body frame and frailty, chronic renal insufficiency, perioperative periods, and concomitant medications (cyclosporine, macrolide antibiotics, azole antifungals) as factors that increase the risk of statin-related complications, with a strength of evidence level of B (moderate) 4, 5

The American College of Cardiology recommends avoiding or using extreme caution with cyclosporine, gemfibrozil, macrolide antibiotics, and azole antifungals due to increased risk of myopathy, with a strength of evidence level of A (high) 5, 4