Infectious diseases caused by bacteria, viruses, mycoplasma, chlamydia and other pathogenic microorganisms are found in various clinical departments, among which bacterial infections are the most common, and therefore antibacterial drugs have become one of the most widely used drugs in clinical practice. While antimicrobial drugs have cured and saved many patients’ lives, there are also adverse consequences caused by the irrational application of antimicrobial drugs, such as the increase of adverse reactions, the growth of bacterial resistance, and the failure of treatment, which have a significant impact on patients’ health and even lives. The irrational application of antimicrobial drugs is manifested in many aspects: preventive use without indication, therapeutic use without indication, wrong choice of antimicrobial drug species and dose, unreasonable route of administration, number of doses and course of treatment, etc. In order to improve the level of antimicrobial treatment of bacterial infections, ensure the safety of patients’ medication and reduce bacterial resistance, the Guidelines for Clinical Use of Antimicrobial Drugs (hereinafter referred to as “Guidelines”) are formulated. The Guidelines elaborate on the principles of antimicrobial therapy for the most important bacterial infections in infectious diseases, the indications for the application of antimicrobial drugs for treatment and prevention, and the principles for the formulation of rational drug administration programs, and list the indications and precautions for commonly used antimicrobial drugs and the etiologic treatment of various common bacterial infections, with the aim of improving the level of antimicrobial therapy for infectious diseases in China, slowing down the development of bacterial drug resistance, and reducing The aim is to improve the level of antimicrobial therapy for infectious diseases in China, slow down the development of bacterial resistance and reduce the cost of medicine. 1, this “guideline” for the clinical application of antibacterial drugs to obtain the best efficacy, and to minimize the avoidance or reduction of adverse reactions and developed, not a textbook or reference book, and does not involve specific drug delivery program. 2.The Guidelines are mainly limited to antibacterial drugs for the treatment of infectious diseases caused by bacteria, mycoplasma, chlamydia, rickettsia, spirochetes, fungi and other pathogenic microorganisms, excluding drugs for the treatment of various viral diseases and parasitic diseases. 3, the basic principles of the clinical application of antibacterial drugs in the “Guidelines” must be followed in clinical treatment, the indications and precautions for various types of antibacterial drugs and the pathogenic treatment of various infections are for the reference of clinicians. 4. In order to strengthen the management of clinical application of antibacterial drugs, the Guidelines also put forward requirements for the management of antibacterial drug application, which should be followed. 5, the “Guidelines” only relate to the domestic clinical use of some varieties of antibacterial drugs, focusing on the antibacterial effects of various drugs, indications and precautions, the details of the clinical application of antibacterial drugs should still refer to the relevant professional books. 6, the “guideline” involves some common and important infectious diseases in various clinical departments, other infections not involved should still refer to the relevant professional books. 7, in the medical work of clinicians should still be combined with the specific circumstances of patients, the development of individualized drug delivery program. 8, “pathogenic treatment” in addition to the “guidelines” listed in the usual choice of drug varieties, clinicians can choose the most appropriate antibacterial drugs according to the patient’s clinical situation, bacterial resistance and local drug supply. Chinese Medical Association Chinese Hospital Management Society Professional Committee of Pharmacy Management Chinese Pharmaceutical Society Professional Committee of Hospital Pharmacy Part I Basic Principles of Clinical Application of Antimicrobial Drugs The application of antimicrobial drugs involves all clinical departments, and the correct and reasonable application of antimicrobial drugs is the key to improving the efficacy, reducing the incidence of adverse reactions, and reducing or slowing down the occurrence of bacterial resistance. Whether the clinical application of antimicrobial drugs is correct and reasonable is based on the following two aspects: (1) whether there are indications for the application of antimicrobial drugs; (2) whether the selected species and drug delivery scheme are correct and reasonable. The basic principles of therapeutic application of antimicrobial drugs I. Only those diagnosed as bacterial infection have indications for the application of antimicrobial drugs based on the patient’s symptoms, signs and blood and urine routine and other laboratory test results, and those initially diagnosed as bacterial infection and those confirmed as bacterial infection by pathogenic examination have indications for the application of antimicrobial drugs, Infections caused by pathogenic microorganisms such as fungi, Mycobacterium tuberculosis, non-tuberculous mycobacteria, mycoplasma, chlamydia, spirochetes, rickettsiae and some protozoa are also indicated for antimicrobial drugs. In the absence of evidence of infection by bacteria and the above pathogenic microorganisms, the diagnosis cannot be established, as well as viral infections, there are no indications for the application of antibacterial drugs. In principle, the selection of antimicrobial drugs should be based on the type of pathogenic bacteria and their sensitivity or resistance to antimicrobial drugs, i.e. the results of bacterial drug sensitivity tests (hereinafter referred to as drug sensitivity). Therefore, medical institutions that have the conditions, inpatients must first take the corresponding specimens before starting antimicrobial therapy, and immediately send bacterial culture, in order to clarify the pathogenic bacteria and drug sensitivity results as soon as possible; outpatients can carry out drug sensitivity work according to the needs of the condition. In critical patients, before the pathogenic bacteria and drug sensitivity results are known, the most likely pathogenic bacteria can be inferred from the patient’s morbidity, site of onset, primary lesion and underlying disease, and the empirical treatment of antibacterial drugs can be given first in combination with the local bacterial resistance status, and after the bacterial culture and drug sensitivity results are known, the drug regimen can be adjusted for patients with poor efficacy. The pharmacodynamics (antibacterial spectrum and activity) and pharmacokinetics (absorption, distribution, metabolism and excretion processes) of various antibacterial drugs are different, so they have different clinical indications. Clinicians should select antimicrobial drugs according to their clinical indications (see “Indications and precautions for various types of antimicrobial drugs”) based on the above-mentioned characteristics of various antimicrobial drugs. The antimicrobial drug treatment plan should be formulated according to the patient’s condition, pathogenic bacteria and antimicrobial drug characteristics. The antimicrobial drug treatment plan should be formulated according to the pathogenic bacteria, infection site, severity of infection and the patient’s physiological and pathological conditions, including the selection of antimicrobial drugs, dose, number of doses, route of administration, course of treatment and combination of drugs. The following principles should be followed when formulating the treatment plan. (A) species selection: select antibacterial drugs according to the type of pathogenic bacteria and drug sensitivity results. (B) the dose: according to the therapeutic dose range of various antibacterial drugs. Treatment of severe infections (such as sepsis, infective endocarditis, etc.) and infections in areas not easily reached by antibacterial drugs (such as central nervous system infections, etc.), the dose of antibacterial drugs should be larger (therapeutic dose range high limit); while the treatment of simple lower urinary tract infections, because most drugs urine drug concentration is much higher than the blood concentration, the application of smaller doses (therapeutic dose range low limit). (C) the route of administration: 1, mild infections can receive oral administration, should be selected to use oral absorption of complete antibacterial drugs, without the use of intravenous or intramuscular injection administration. The initial treatment of patients with severe infections and systemic infections should be given intravenously to ensure the efficacy of the drug; when the condition improves and can be taken orally, it should be switched to oral administration as early as possible. 2, the local application of antibacterial drugs should be avoided as far as possible: after the local application of antibacterial drugs in the skin mucosa, they are rarely absorbed and cannot reach the effective concentration at the infection site, which is easy to cause allergic reactions or lead to drug-resistant bacteria, so the local application of antibacterial drugs should be avoided when treating systemic infections or organ infections. Local application of antimicrobial drugs is limited to a few cases, for example, when it is difficult to achieve therapeutic concentration at the infected site after systemic administration, local administration can be added as an adjunctive treatment. This is seen in the treatment of central nervous system infections where certain drugs can be administered intrathecally at the same time; the injection of antibacterial drugs into the abscess cavity of encapsulated thick-walled abscesses and the local administration of drugs for ophthalmic infections. Certain infections of the skin surface and mucosal surfaces such as the oral cavity and vagina can be treated with topical application of antibacterial drugs or topical application, but topical application of species mainly for systemic application should be avoided. Topical medications should be used with bactericidal agents that are less irritating, less easily absorbed, less likely to lead to drug resistance and less likely to cause allergic reactions, penicillins, cephalosporins and other drugs that are prone to allergic reactions should not be applied topically. Aminoglycosides and other ototoxic drugs should not be used as local ear drops. (iv) The number of times of administration: In order to ensure that the drug can maximize its efficacy in the body and kill the pathogenic bacteria at the foci of infection, the drug should be administered according to the principle of combining pharmacokinetics and pharmacodynamics. Penicillins, cephalosporins and other β-lactams, erythromycin, clindamycin and other drugs with short elimination half-life should be given several times a day. Fluoroquinolones, aminoglycosides, etc. can be given once a day (with the exception of severe infections). (E) course of treatment: the course of antibacterial drugs varies depending on the infection, and it is generally advisable to use until the body temperature is normal, 72-96 hours after the symptoms subside, special circumstances, proper treatment. However, sepsis, infective endocarditis, septic meningitis, typhoid fever, brucellosis, osteomyelitis, hemolytic streptococcal pharyngitis and tonsillitis, deep fungal disease, tuberculosis, etc. require a longer course of treatment to completely cure and prevent recurrence. (F) the combination of antibacterial drugs to have clear indications: a single drug can be effectively treated infections, do not need to combine drugs, only in the following cases when there are indications for the combination of drugs. 1, the original bacteria have not been identified serious infections, including serious infections of immunodeficient people. 2, single antibacterial drugs can not control the aerobic bacteria and anaerobic bacteria mixed infection, 2 or more pathogenic bacteria infection. 3.Serious infections such as infective endocarditis or sepsis that cannot be effectively controlled by a single antimicrobial drug. 4.Infections that require long course of treatment, but the pathogenic bacteria are prone to resistance to certain antibacterial drugs, such as tuberculosis, deep fungal disease. 5.Because of the synergistic antibacterial effect of drugs, the dose of antibacterial drugs with high toxicity should be reduced when combined with drugs, such as amphotericin B and flucytosine when combined with cryptococcal meningitis, the dose of the former can be reduced appropriately, so as to reduce its toxic reaction. The combination of drugs with synergistic or additive antibacterial effects is appropriate, such as the combination of penicillins, cephalosporins and other β-lactams with aminoglycosides, and the combination of amphotericin B with flucytosine. The combination of 2 drugs is usually used, and the combination of 3 and more drugs is only applicable to individual cases, such as the treatment of tuberculosis. In addition, it must be noted that the combination of drugs will increase the number of adverse drug reactions. The basic principles of preventive application of antimicrobial drugs I. Preventive medication in internal medicine and pediatrics 1, for the prevention of infection caused by the invasion of one or two specific pathogenic bacteria in the body, may be effective; if the purpose is to prevent any bacterial invasion, it is often ineffective. 2.Prevention of infections occurring over a period of time may be effective; long-term preventive medication often fails to achieve the purpose. 3.Preventive medicine may be effective if the patient’s primary disease can be cured or in remission. If the primary disease cannot be cured or remitted (such as immunodeficient patients), preventive medicine should be used as little as possible or not. For immunodeficient patients, it is advisable to closely observe their condition, and once the signs of infection appear, send the relevant specimens for culture at the same time, first give empirical treatment. 4, usually not suitable for routine preventive application of antibacterial drugs: common cold, measles, chickenpox and other viral diseases, coma, shock, poisoning, heart failure, tumors, the application of adrenal corticosteroids and other patients. II. Preventive medication for surgery (a) The purpose of preventive medication for surgery: to prevent incisional infection after surgery, as well as clean – contaminated or contaminated surgical site infection after surgery and possible systemic infection after surgery. (B) the basic principles of surgical prophylaxis: according to whether the surgical field is contaminated or contaminated may, decide whether to prevent the use of antibacterial drugs. 1, clean surgery: the surgical field is a sterile part of the human body, no local inflammation, no injury, and does not involve the respiratory tract, gastrointestinal tract, genitourinary tract and other organs of the human body with the outside world. The surgical field is free of contamination and usually does not require prophylactic antibacterial drugs. Prophylactic drugs can be considered only in the following cases: (1) large scope of surgery, long duration and increased chance of contamination; (2) surgery involving important organs, which will cause serious consequences once infection occurs, such as head surgery, heart surgery, intraocular surgery, etc.; (3) foreign body implantation surgery, such as artificial heart valve implantation, permanent cardiac pacemaker placement, artificial joint replacement, etc, (4) High-risk groups such as those of advanced age or immunodeficient persons. 2.Cleaning-contamination surgery: upper and lower respiratory tract, upper and lower gastrointestinal tract, genitourinary tract surgery, or surgery via the above organs, such as major transoral pharyngeal surgery, transvaginal hysterectomy, transrectal prostate surgery, and open fracture or trauma surgery. Because of the presence of a large number of human parasitic flora at the surgical site, infection may be caused by contamination of the surgical field during surgery, so these surgeries need to be prevented with antibacterial drugs. 3. Contaminated surgery: surgery that has caused serious contamination of the surgical field due to large spillage of body fluids from the gastrointestinal tract, urinary tract, biliary tract or open trauma without dilation. These surgeries need preventive antibacterial drugs. Pre-operative bacterial infection surgery, such as peritonitis of perforated abdominal organs, abscess resection, gas gangrene amputation, etc., is the therapeutic application of antimicrobial drugs, does not belong to the scope of preventive applications. 4, the choice of antibacterial drugs for surgical prophylaxis and the method of administration: the choice of antibacterial drugs depends on the purpose of prevention. To prevent postoperative incision infection, the drug should be selected for Staphylococcus aureus (hereinafter referred to as Staphylococcus aureus). To prevent surgical site infections or systemic infections, drugs should be selected according to the type of contamination or possible contamination in the surgical field, such as antibacterial drugs that are effective against Escherichia coli and Bacteroides fragilis before colon or rectal surgery. The antimicrobial drugs chosen must be sure of their efficacy, safe, easy to use and relatively low in price. Method of administration: For those who undergo clean surgery, the drug should be administered within 0.5 to 2 hours before surgery, or at the beginning of anesthesia, so that a drug concentration sufficient to kill the bacteria that invade the incision during surgery has been reached in the local tissues when the surgical incision is exposed. A second dose may be given intraoperatively if the duration of surgery exceeds 3 hours or if blood loss is high (>1500 ml). The effective duration of antimicrobial drug coverage should include the entire surgical procedure and 4 hours after the end of surgery, with the total duration of prophylaxis not exceeding 24 hours, which may be extended to 48 hours in individual cases.