ANTIBIOTICS-3

  1. What are the 4 classes of beta-lactams?
    • 1- Penicillins
    • 2- Cephalosporins
    • 3- Carbapenems
    • 4- Monobactams
  2. All beta-lactams have _________ in their chemical structures
    4-membered lactam ring
  3. What are the 4 mechanisims of resistace to beta-lactams?
    • 1- inactivation via beta-lactamases
    • 2- modification of target PBPs
    • 3- impared penetration of the antibiotic
    • 4- active efflux
  4. Which mechanisim of bacterial resistance to beta-lactams is the most important?
    inactivation of the antibiotic via beta-lactamases
  5. True or false, impared penetration of beta-lactams into the cell can only occur in gram positive bacteria.
    False, it only occurs in gram negative bacteria
  6. Active efflux pumps are _______ which causes resistance to beta-lactams
    up-regulated
  7. Reistant strains produce PBPs that have ____ affinity for binding to beta-lactams
    • Low
    • (Modification of target PBPs)
  8. protease

    synthesis is R-factor mediated or induced by the presence of beta-lactams
    beta-lactamase
  9. True or false, beta-lactamases can be narrow or broad in their substrate specificity
    True
  10. How do beta-lactamases inactivate beta-lactam antibiotics?
    The lactamase cleaves the lactam ring rendering it inactive
  11. What are the Class I beta-lactamase inhibitors? (3)
    • 1- clavulanic acid
    • 2- sulbactam
    • 3- tazobactam
  12. What are the Class II beta-lactamase inhibitors? (1)
    1- Carbapenems
  13. weak inhibitors of beta-lactamases

    potent inhibitors of PBPs
    Class II Inhibitors of beta-lactamases
  14. potent inhibitors of beta-lactamases

    weak inhibitors of PBPs
    Class I Inhibitors of beta-lactamases
  15. What is the major difference in Class I and Class II beta-lactamase inhibitors?
    Class II is NOT used in combination with antibiotics
  16. Carbapenems are hydrolyzed by what 2 enzymes?
    • 1- carbapenemases
    • 2- metallo-beta-lactamases
  17. What are the 3 carbapenem drugs on the market?
    • 1- imipenem
    • 2- meropenem
    • 3- doripenem
  18. Augmentin
    Amoxicillin + K-Clavulanate
  19. Timentin
    Ticarcillin + K-Clavulanate
  20. Unasyn
    Ampicillin + Sulbactam Na
  21. Zosyn
    Piperacillin + Tazobactam Na
  22. True or false, Class II is more electronegative than Class I.
    False, it is less electronegative
  23. Which class of beta-lactamase inhibitors binds to beta-lactamase and causes prolonged inactivation?
    Class I ONLY
  24. Why can you not physically mix an aminoglycoside and a beta-lactam?
    The aminoglycoside will cleave the amide bond in the beta-lactam ring rendering them both inactive
  25. True or false, the aminoglycoside/beta-lactam combination antibiotic is antagonistic.
    False, it is synergistic---the 2 drugs must be administered separately but they work together in vivo
  26. True or false, beta-lactamases travel into the periplasmic space of gram negative bacteria
    True
Author
dr.fizzle
ID
66066
Card Set
ANTIBIOTICS-3
Description
725
Updated