Metronidazole injection, belongs to the nitroimidazole class of antibiotics. Its antibacterial spectrum is mainly anaerobic bacteria, and it is ineffective for aerobic or parthenogenic anaerobic bacteria. Among the antibacterial spectrum are Bacteroides fragilis, Mycobacterium fungoides, Clostridium tetani, Clostridium perfringens, Clostridium difficile, etc. It is resistant to Actinomyces and Lactobacillus. It can be used to treat, amebiasis, Trichomonas infection, Giardia infection, and Leishmania protozoa infection of the skin. Adverse reactions are mainly gastrointestinal. After injection, nausea, stomach pain and abdominal pain may occur, as well as neurological symptoms such as headache and dizziness. There is also the possibility of allergy, which can be accompanied by rash and itching, and a metallic taste in the mouth. These adverse reactions, however, are generally reversible and are able to recover after discontinuation of the drug. It should not be used by pregnant women and those who are breastfeeding.