Metronidazole has a powerful killing effect on both trichomonas and amoeba protozoa, and it can also be used to treat anaerobic infections, so it is mainly used in the clinical treatment of amoebic dysentery and amoebic liver abscess, as well as trichomonas vaginitis and other diseases. The side effects of metronidazole are mainly manifested in the gastrointestinal aspect, nausea, vomiting, loss of appetite, abdominal pain, etc. In the nervous system some patients will have headache, dizziness or even numbness of the limbs, ataxia. If the high dose can even lead to convulsions, as well as some patients can appear urticaria, skin itching, cystitis, urinary difficulties and leukopenia, etc., but these adverse reactions are reversible, after discontinuing the drug are able to recover on their own.