Imatinib-induced rhabdomyolysis: A case report.

Imatinib, a tyrosine kinase inhibitor used for chronic myeloid leukemia (CML) and gastrointestinal stromal tumors (GIST), is associated with myalgia and creatine kinase (CK) elevations, though severe rhabdomyolysis and myopathy are rare. We report an 83-year-old woman with CML who developed progressive proximal weakness, dark urine, and acute kidney injury after three years of imatinib therapy. Laboratory evaluation revealed CK >24,000 U/L, transaminitis, and myoglobinuria. MRI showed diffuse muscle and fascial edema, while autoimmune testing was negative. Imatinib and rosuvastatin were discontinued, and the patient was managed with intravenous fluids and supportive care. CK and renal function normalized within 10 days, with substantial recovery of strength. The strong temporal relationship between drug withdrawal and improvement implicates imatinib as the etiology. This case represents one of the most severe reported instances of imatinib-induced rhabdomyolysis. Early recognition and discontinuation are essential to prevent life-threatening sequelae.