Beta-lactams

Mechanism of action

• disruption of bacterial cell wall by binding to penicillin-binding proteins involved in cell wall synthesis

Resistance by

1. prevention of interaction between antibiotic and target penicillin-binding protein

   • seen with Gram -ve species, particularly Pseudomonas

2. decreased binding of PBP to antibiotic

3. hydrolysis of antibiotic by beta lactamase

Drugs in class

• Penicillins

  • benzylpenicillin, phenylmethoxypenicillin

  • flucloxacillin (nafcillin, methicillin, oxacillin, cloxacillin, dicloxacillin)

  • ampicillin, amoxicillin, tircarcillin, piperacillin, (carbenicillin, , mezlocillin,)

• Cephalosporins

  • cephalexin, cephalothin, cefazolin, cephapirin, cephradine

  • cefaclor, cefamandole, cefuroxime, cefotetan, cefoxitin

  • cefixime, cefotaxime, cetriaxone, ceftazidime

  • cefepime, cefpirome

• Carbapenems

  • imipenem

  • carbopenem

• Monobactams

  • aztreonam