Be alert! Omeprazole-associated rhabdomyolysis! In clinical work, the addition of proton pump inhibitors (PPIs), of which omeprazole is also frequently used, is often necessary to prevent stress ulcers or to prevent gastric mucosal injury.Critical Care Journal published the following case report of rhabdomyolysis in a patient with peptic ulcer treated with omeprazole. Male, 20 years old, previously healthy, presented with “epigastric pain”. Upper gastrointestinal endoscopy showed the presence of an active duodenal ulcer. After admission, he was given “omeprazole 20mg intravenously 2/day”. On day 14, the patient developed muscle pain, mainly in both lower extremities, and serum creatine kinase was elevated to 28314 IU/L. On day 16, the patient was transferred to the intensive care unit, where omeprazole-related rhabdomyolysis was diagnosed and omeprazole was immediately stopped and treatment with rapid rehydration, bedside hemofiltration and alkalinization of urine was started. The patient recovered and was discharged from the hospital on day 38 of admission. Proton pump inhibitor-associated rhabdomyolysis is very rare. The pathogenesis of proton pump inhibitor-associated rhabdomyolysis is not well understood. Possibly: 1) Melazol specifically inhibits H+-K+-ATPase on gastric wall cells, which is also present in other tissues, including vascular smooth muscle cells. Inhibition of H+-K+-ATPase can cause arterial constriction and local muscle ischemia.2) Insulin-like growth factor binding protein 1 is an important intermediate in the synthesis of muscle proteins, and omeprazole can activate the gene expression of this intermediate through the aryl hydrocarbon receptor. Rhabdomyolysis (RM): a group of clinical syndromes in which rhabdomyolysis (skeletal muscle) cells are damaged and lysed by various causes, resulting in altered cell membrane integrity and release of myocyte contents (including potassium, phosphate, myoglobin, creatine kinase and uric acid) into the extracellular fluid and blood circulation and can be fatal. Common causes of rhabdomyolysis include excessive exercise, muscle crush injury, ischemia, metabolic disorders, hyperthermia, drugs, toxins, autoimmunity, infection, and hereditary muscle diseases.