Immune-mediated necrotizing myopathy associated with atorvastatin use: Case report and literature review

Rodríguez-Chávez L.Á.; Romero-Díaz M.Y.; Vargas Machuca-Carranza C.A.; Cabanillas-López J.G. · Medicina Clinica Practica (2026) · DOI: 10.1016/j.mcpsp.2026.100534

Resumen

Statin-associated autoimmune necrotizing myositis (ANM) is a rare entity characterized by progressive proximal muscle weakness, marked and persistent elevation of creatine phosphokinase, and the presence of anti-HMGCR autoantibodies. Unlike toxic statin-induced myopathy, ANM persists even after discontinuation of the drug due to an autoimmune response directed against the HMGCR enzyme. We report the case of a 75-year-old man on long-term atorvastatin therapy who developed severe muscle weakness, dysphagia, and respiratory involvement, initially suspected to be Guillain–Barré syndrome. The autoimmune profile revealed positive anti-HMGCR antibodies, confirming the diagnosis. Treatment included discontinuation of atorvastatin, glucocorticoids, azathioprine, and intravenous immunoglobulin, with partial improvement. This case highlights the importance of timely recognition of ANM to prevent severe complications and to guide early immunosuppressive therapy that may improve functional prognosis.

Instituciones: Universidad Privada Antenor Orrego