The main drugs used to reduce blood ammonia in hepatic encephalopathy are lactulose, which changes the environment in the intestine and reduces ammonia absorption and is used as the drug of choice for the treatment of hepatic encephalopathy attacks. Lactulose lowers the pH in the intestine, resulting in a reduction in ammonia formation as well as ammonia absorption, either orally or intranasally via lactulose. The main drugs used to remove ammonia include glutamate, arginine, acetylglutamine, and potassium magnesium menthylate, usually in combination with acetylglutamine in clinical practice. Acetylglutamine is able to cross the blood-brain barrier and can be converted into glutamate after entering the brain to reduce the phenomenon of high ammonia in the brain. The treatment of hepatic encephalopathy is comprehensive, in terms of diet to ensure nutrition, but patients should stop eating foods containing protein, especially to avoid the intake of animal protein.