Antibiotics, also known as antimicrobials, refer to a class of drugs that can inhibit and kill bacteria. There is no definite clinical conclusion as to how many days antibiotics can be used in a row, and it depends on the specific type of antibiotics, the type of infecting bacteria, the patient’s own constitution, the degree of drug resistance, and many other influencing factors. In the absence of organic pathology, patients apply antibiotics to treat symptoms of infection usually in 3-5 days, some patients can be extended or shortened according to the specific situation, but the overall situation does not exceed one week. Antibiotics mainly include β-lactams, quinolones, macrolides, aminoglycosides, etc. β-lactams can be further divided into penicillins, cephalosporins, etc. Antibiotics can be used clinically to treat or prevent bacterial infections. The decision of how many days an antibiotic can be used in a row should be made by the doctor based on the type of pathogenic bacteria the patient is infected with, the clinical symptoms, the site of infection and other factors. If the patient’s condition is more complex and requires long-term antibiotic treatment, he or she may also choose to use it in combination with other drugs. It helps to reduce bacterial resistance, reduce the chance of adverse reactions, etc., so as to play a better therapeutic effect. However, it is necessary to avoid the abuse of antibiotics, so as not to cause dysbiosis, or produce metabolic reactions, and in serious cases can even cause some damage to the liver, kidneys and other organs and the nervous system. It is recommended that patients actively go to the hospital when symptoms of infection appear, according to the specific circumstances, under the guidance of a professional doctor, the correct application of antibiotics on time, according to the amount, according to the course of treatment, avoid unauthorized application or discontinuation of drugs, etc.