Thiocolchicoside-induced liver injury

Drug-induced liver injury (DILI) is an important cause of mortality and morbidity in the general population. Patients suffering from DILI may present with symptoms ranging from minor, nonspecific changes in hepatic structure and function to fulminant hepatic failure or chronic hepatitis. Thiocolchicoside is widely used as a muscle relaxant. The primary side effects of thiocolchicoside are nausea, somnolence, allergy and vasovagal reaction. Epileptic seizures following thiocolchicoside ingestion have been reported in a few cases, but other systemic side effects, such as cardiotoxicity, nephrotoxicity or hepatotoxicity, have not been reported. Here, we report the case of a patient whose hepatic and cholestatic enzyme levels were elevated during thiocolchicoside therapy and returned to normal after thiocolchicoside was discontinued. Resolution of the hepatotoxicity was observed after discontinuation of the drug and the initiation of conservative treatment measures. An objective causality assessment, based on a Naranjo score of 6, suggests that the liver injury was related to the thiocolchicoside treatment. A 58-year-old man was admitted to the emergency clinic with abdominal discomfort, nausea and a yellowish discoloration of the sclera. Complete blood count and hemostasis parameters were normal. The patient’s biochemical test results were as follows: blood urea nitrogen 30 mg/ dl (normal: 0 to 40 mg/dl), creatinine 0.9 mg/dl (normal: 0.6 to 1.3 mg/dl), albumin 3.7 mg/dl (normal: 3.5 to 4.5 mg/dl), lactic dehydrogenase 320 IU/L (normal: 0 to 125 IU/L), total bilirubin 3.5 mg/dl (normal: 0.6 to 1.2 mg/dl) with direct bilirubin 3 mg/dL (normal: 0.2 to 0.4 mg/dl) and indirect bilirubin 0.4 mg/dl (normal: 0.4 to 0.8 mg/dl), alkaline phosphatase 280 IU/L (normal: 64 to 160 IU/L), gamma glutamyl transpeptidase 204 IU/L (normal: 20 to 64 IU/L), alanine aminotransferase 368 IU/L (normal: 0 to 54 IU/L), aspartate aminotransferase 346 IU/L (normal: 0 to 34 IU/L), serum amylase 280 IU/L (normal: 0 to 250 IU/L). The patient was taking no drugs other than thiocolchicoside and was not consuming alcohol at the time. Viral serologies (hepatitis A, B and C; cytomegalovirus; Epstein-Barr; herpes simplex; and HIV) and all of the tests for autoantibodies typical of autoimmune liver diseases were negative. Abdominal ultrasonography and magnetic resonance cholangiopancreatography revealed no pathology. Thiocolchicoside was discontinued, and liver and cholestatic enzymes began to decrease, but complete normalization of biochemical parameters was not achieved until 12 days later.