Levofloxacin 0.5g, the maximum dose can be increased to 0.6g a day, divided into 3 oral doses, some over-the-counter use (multidrug-resistant tuberculosis) can reach 1g/day. Levofloxacin is divided into two types: tablets and injections, with the 0.5g dosage form dominating the tablets and the 0.2g and 0.4g dosage forms dominating the injections. The conventional maximum daily dose of both types of dosage forms is 0.6 g. Foreign dosage and some over-the-schedule dosage can be up to 0.75 g and 1 g/day. Levofloxacin is indicated for acute bronchitis, tonsillitis, pyelonephritis, pelvic inflammatory disease, skin and soft tissue infections, bacterial dysentery, sepsis and other systemic infections. According to the severity of the disease, the dose of use can be increased or decreased appropriately. Common adverse reactions are mainly nausea, diarrhea, headache, insomnia and so on. Contraindicated for those who are allergic to quinolone drugs, as well as children, pregnant women. Liver and kidney insufficiency should be used with caution. Specific use, should be based on the actual clinical situation, under the guidance of the physician, do not increase or decrease the dosage, to avoid the occurrence of adverse events.