Irreversible metronidazole encephalopathy in an elderly woman with primary biliary cholangitis.

An 82-year-old woman with primary biliary cholangitis was diagnosed with an irreversible neurological disorder, caused by metronidazole (MNZ)-induced encephalopathy. Although the disorder is a reversible pathological condition, in rare cases, it can cause serious sequelae or could even be fatal. Therefore, medications should be administered carefully, particularly in patients who require long-term administration of large doses or those with liver dysfunction.