Summary High-Yield Katzung Pharmacology: Beta-Lactams & Cell Wall Synthesis Inhibitors

β-lactams

Inhibitors of cell wall synthesis

1. Penicillin
a. Amoxicillin
b. Penicillin G
c. Penicillin V
d. Ampicillin
2. Cephalosporin
a. 1st gen
i. Cefazolin
ii. Cefadroxil
iii. Cephalexin
b. 2 gen
nd

i. Cefaclor
ii. Cefamandole
iii. Cefoxitin
c. 3rd gen
i. Clexime
ii. Ceflazidime
iii. Ceftriaxone
3. Carbapenams
a. Imipenem
4. Monobactams
a. Aztreonam



Penicillin classification:

1. Pen G and esters
a. Procaine penicillin G
b. Penicillin G
2. Acid resistant
a. Pen V
3. Penicillinase-resistant
a. Acid labile: Methicillin
b. Acid resistant: Cloxacilin
4. Effective against some gm +ve and -ve
a. Amoxicillin, ampicillin
5. Extended spectrum penicillins

, a. Carboxypenicillins:
i. Carbenicillin
ii. Ticarcillin
b. Ureidopenicillins
i. Piperacillin
c. Amidopenicillins
i. Mecillinam
6. Penicillins with β – lactamase inhibitors:
a. Amoxicillin – clavulanic acid
b. Ampicillin – Sulbactam



Penicillin inhibits enzymes needed for cross-linking of peptidoglycans in cell
walls of bacteria. It binds to penicillin binding proteins with the β – lactam
ring, which is found on penicillin molecules.

Transpeptidase-catalyzed reaction is inhibited. Thus no cross-linking of
peptidoglycans.



MOA:

1. Enter gm +ve bacteria through porins
2. Binds to transpeptidase enzyme (PBPs)
3. Inhibition occurs




β-lactam MOA:

1. Bind penicillin binding proteins
2. Inhibit cross-linking of peptidoglycan