Commonly seen in the clinic are levofloxacin capsules, ciprofloxacin capsules, norfloxacin capsules, all of which belong to the third generation of quinolone antibiotic drugs, with bactericidal effects on a wide range of gram-negative bacteria, and weaker effects on gram-positive bacteria. So they are mainly used for pneumonia, sinusitis, respiratory tract infections, etc., urinary tract infections, intestinal infections, typhoid fever, etc., respectively. Adverse reactions are mainly gastrointestinal reactions, liver damage and central reactions, but these drugs have photosensitivity reactions, inhibition of cartilage development and central nervous system symptoms, so children under 18 and pregnant women are forbidden to use. Commonly used in ophthalmology is levofloxacin capsules, which is a broad-spectrum antibacterial drug with relatively strong antibacterial effect, and can be used for the systemic drug treatment of conjunctivitis, bacterial keratitis, erysipelas and other diseases. Of course, this kind of antibiotic must be used correctly under medical advice, and cannot be used indiscriminately on its own.