Usage and Dosage: (1) For the prevention of postoperative anaerobic infection: mainly used in abdominal surgeries and obstetric and gynecological surgeries. Adults: 400 mg per os every 8 hours for 24 hours before surgery, followed by intravenous or rectal administration after surgery until the patient is able to take tablets orally. Children: Less than 12 years old: a single dose of 20-30 mg/kg, 1-2 hours before the surgery; Neonates with less than 40 weeks of gestation: a single dose of 10 mg/kg before the surgery. (2) Treatment of anaerobic infection: The course of treatment is about 7 days, which also depends on the severity of the patient's condition based on clinical and bacteriological evaluation. Adults: Initial dose of 800 mg, followed by a dose of 400 mg every 8 hours. Children: 8 weeks to 12 years old: routine daily dose is 20-30 mg/kg, which can be administered at a single time or at a single dose of 7.5 mg/kg every 8 hours. Depending on the severity of the infection, the daily dose can be increased to 40 mg/kg. The course of treatment is usually 7 days. Infants aged less than 8 weeks: Daily dose of 15 mg/kg, which can be administered at a single time or at a single dose of 7.5 mg/kg every 12 hours. In neonates with less than 40 weeks of gestation, accumulation of metronidazole may occur within the first week of birth. Therefore, it is strongly recommended to monitor the metronidazole concentration in serum following several days of treatment. (3) Leg ulcers and pressure sores: Adults or children over 10 years old: 400 mg tid for 7 days.
