First, the definition of antibacterial drugs:
Antibacterial drugs generally refer to drugs with bactericidal or bacteriostatic activity, including antibiotics, sulfonamides, imidazoles, nitroimidazoles, quinolones and other synthetic drugs. Some products obtained by cultivating microorganisms such as bacteria, actinomycetes and fungi, or the same or similar substances made by chemical semi-synthesis methods can also be chemically synthesized.
Two, antibacterial drugs are mainly divided into eight categories:
Among them, β -lactams include penicillins, cephalosporins, carbapenems, β -lactams containing enzyme inhibitors and monocyclic amides. Aminoglycosides; Tetracyclines; Fluoroquinolones; Folic acid pathway inhibitor; Chloramphenicol; Glycopeptides include vancomycin and teicoplanin; Macrolides. The application of antibacterial drugs should be reasonably selected according to different infectious diseases.
Antibacterial activity of commonly used antibiotics;
1, penicillin:
Gram-positive bacteria and gram-negative bacteria, Haemophilus, various pathogenic spirochetes and most bovine actinomycetes. Classification: penicillin G, phenoxypenicillin, enzyme-resistant penicillin (oxacillin), broad-spectrum penicillin (ampicillin, piperazine), penicillin acting on gram-negative bacteria (methicillin, timocillin).
2. Cephalosporin:
It has strong antibacterial activity, penicillinase resistance, high clinical efficacy, low toxicity and few allergic reactions, and can be divided into three generations: the first generation is mainly used for the infection of gram-positive bacteria and some gram-negative bacteria, and has poor tolerance to β-LA
The second generation is stable to most β-LA, and its antibacterial spectrum is wider than that of the first generation. It has strong effect on gram-negative bacteria, but poor activity on Enterobacter and Pseudomonas aeruginosa.
The third generation is stable to most β-LA and has strong activity to gram-negative bacteria, but its effect on G+ cocci is not as strong as that of the first and second generations. Cefoperazone and ceftazidime have good effects on Pseudomonas aeruginosa, and the half-life of ceftriaxone is long, up to 8 hours.
3, cephamycin class:
Cefoxitin has strong activity against gram-positive bacteria, gram-negative bacteria, anaerobic bacteria or aerobic bacteria, and is highly stable against β-LA.
4. Monocyclic β -lactam antibiotics:
Aztreonam has a strong effect on gram-negative bacteria, is stable to enzymes and has a low incidence of cross-allergy.