(精选)β-内酰胺酶抑制剂抗生素的使用及作用机理(英文课件)β-Lactam antibiotics教学课件.pptVIP

β-Lactam antibiotics Classification Penicillins Cephalosporins Other β-Lactam drugs Cephamycins（头霉素类） Carbapenems（碳青霉烯类） Oxacephalosporins （氧头孢烯类） β-Lactamase inhibitors（ β-内酰胺酶抑制剂） Monolactums（单环β-内酰胺类）  Mechanism of action Inhibiton of bacterial cell wall synthesis Target: PBPs(penicillin-binding proteins) Cell-wall autolytic enzyme Mechanism of resistance Inactivation of drug by β-lactamase Trapping mechanism Modification of PBPs Impared penetration of drug to target PBPs Absence of autolysins Penicillins History Basic structure: 6-APA Classification Natural penicillins Semisynthesized penicillins Penicillin G Chemistry Antimicrobial activity Gram-positive cocci Streptococci ,pneumococci , staphylcocci Gram-positive rods B.anthracis, diphtheriae, clostridium terani Penicillin G Gram-negative cocci Meningococci, diplococcus gonorrhoeae Spirochete treponema pallidum leptospirrosis Pharmacokinetics Absorption Distribution metabolism Excretion 90% tubular secretion 10% glomerular filtration Synthesized penicillins Acid-resistant penicillins Penicillinase-resistant penicillins Extended-spectrum penicillins Extended-spectrum penicillins against P.aeruginosa Penicillins against gram-negative bacteria Acid-resistant penicillins Drugs: penicillin V,phenethicillin Character Orally effective, not resist β-Lactamase Lower potency than penicillin G Clinical uses: moderate infections Adverse reactions: allergic reaction Penicillinase-resistant penicillins Drugs:oxacillin, cloxacillin, dicloxacillin Clinical use Infection caused by penicillin-resistant staphylococci Extended-spectrum penicillins Ampicillin, amoxycillin, pivampicillin Oral effective, susceptible to β-Lactamase Broad spectrum: G+ G- Clinical uses: infection caused by gram-negative rods Extended-spectrum Penicillins against P.aeruginosa Carbenicillin,sulbencillin, ticarcillin, furbencillin, piperacillin, mezlocillin Character: more activity on P.aeruginosa Usually in combinat