Severe Rosuvastatin-Associated Myopathy With Persistent HyperCKemia and Transaminitis: Early Outpatient Recognition and Diagnostic Pitfalls

Statin-associated muscle symptoms range from mild myalgia to severe myopathy and, rarely, immune-mediated necrotizing myopathy (IMNM). We report the case of a 62-year-old woman who had been receiving rosuvastatin 20 mg daily for approximately four months and presented to an outpatient clinic with four weeks of progressive fatigue, generalized myalgia, proximal muscle weakness, and difficulty walking. Initial evaluation revealed marked hyperCKemia, with a creatine kinase (CK) level of 8,586 U/L, elevated C-reactive protein (CRP) and lactate dehydrogenase (LDH) levels, transaminitis, and preserved renal function. Physical examination demonstrated diffuse muscle tenderness and reduced strength involving both the upper and lower extremities without focal neurologic deficits. Rosuvastatin was discontinued, and the patient was urgently referred to the emergency department for further evaluation and stabilization, with additional rheumatology and endocrinology referrals. According to the patient’s family, she was hospitalized for four days; however, inpatient records and treatment details were not available to the author. Following this family-reported hospitalization, she continued specialist care outside the author’s clinic. Serial laboratory results available through day 54 demonstrated persistent CK elevation, peaking at 9,239 U/L, followed by a gradual decline to 7,018 U/L and 3,550 U/L, while renal function remained preserved. The author could not determine whether confirmatory investigations were subsequently performed or verify the patient’s later treatment, recovery of muscle strength, final specialist diagnosis, or long-term clinical outcome from the available records. This case highlights the importance of early CK testing in statin-treated patients presenting with progressive weakness and emphasizes that aminotransferase elevation in this setting may reflect skeletal muscle injury rather than primary hepatic disease. Early recognition, prompt statin discontinuation, emergency evaluation when clinically indicated, and timely specialist referral are essential to reduce the risk of complications.