Norfloxacin is a quinolone drug, mainly used for the treatment of urinary tract infections and gastrointestinal infections, etc. The usual dosage is 2-4 capsules taken twice a day. It should be taken on an empty stomach and with more than 250mL of water, as high doses are likely to produce crystalluria. It should also be contraindicated in adolescents under 18 years of age because it can cause cartilage damage in adolescents; it should be avoided in patients with a history of epilepsy and during the nursing period of pregnant women. It is clinically recommended that this product be used under the guidance of a regular hospital physician and not purchased by the patient.