Cell wall inhibitors

Question 1

What are the classes of Beta-lactams?

Answer 1

Penicillins, cephalosporin, carbapenems, aztreonam

Question 2

What is the action of Beta-lactams?

Answer 2

Bind to Pencillin Binding Proteins which are transpeptidases to block cross linking of peptidoglycan in cell wall synthesis

Question 3

Penicillinase-resistant penicillins

Answer 3

nafcillin, dicloxacillin

Question 4

Forms of Penicillin

PO, IV, and IM

Answer 4

Penicillin V, Penicillin G, and Benzathine (longer acting)

Question 5

What is probenecid?

Answer 5

Increases the action of penicillin by reducing renal secretion of weak acids.

Question 6

What are Beta-lactamases?

Answer 6

They are a class that can be taken along with penicillin to bind irreversibly to penicillinase

Question 7

What are Aminopenicillins and antipseudomonal penicillin

Answer 7

Wider spectrum penicillinase-susceptible drugs (cover gram negative)

Question 8

Beta-lactasmase inhibitors

Answer 8

clavulanate, sulbactam, tazobactam

Question 9

Aminopenicillins

Answer 9

ampicillin, amoxicillin

Question 10

Antipseudomonal penicillin

Answer 10

piperacillin, ticarcillin

Question 11

2. Penicillinase-resistant penicillins

Answer 11

nafcillin, dicloxacillin

Question 12

Cephalosporins

Answer 12

1st gen- cefazolin
2nd gen- cefoxitin, cefaclor
3rd gen- ceftriaxone, cefotaxime, ceftazidime
4th gen- cefepime
5th gen- ceftaroline

Question 13

Carbapenems

Answer 13

Imipenem/cilastatin, meropenem

Question 14

What is Aztreozam?

Answer 14

Cell wall inhibitor if allergic to penicillin
Monocyclic beta-lactams
Cell wall inhibitor and binds to polypeptide binding protein
Gram-negative rods

Question 15

Vancomycin

1. Mechanism?
2. Spectrum?

Answer 15

1. Binds with high affinity to the D-alanyl-D-alanine terminus of the cell wall precursor unit, inhibiting release from the bactoprenol carrier, thus preventing peptidoglycan synthesis. Inhibits the transglycosylase reaction.
   * Not beta lactam
2. Gram positive esp . MRSA, C difficile

Question 16

Bacitracin mechanism?

Answer 16

prevents the dephosphorylation of the bactoprenol carrier needed for elongation of the peptidoglycan cell wall.
*Not Beta-lactam

Question 17

Polymixin B - Mechanism and spectrum?

Answer 17

Mechanism: Bind to phosphatidylethanolamine in the membrane creating holes ultimately leading to the release of cellular contents.
*Not Beta-lactam

Spectrum: Multidrug resistant Gram negative bacilli including Pseudomonas aeruginosa and Klebsiella pneumoniae.
*Used in combination with other antibiotics to help facilitate entry

Question 18

Daptomycin - Mechanism and spectrum?

Answer 18

Mechanism: Binds to the cell membrane and aggregates leading to depolarization of membrane and cell death, bactericidal

Spectrum: Only Gram-positive organisms (Vanco-resistant, MRSA)