lect 14: inhib cell wall syn II Flashcards
what is the mechanism of action of cephalosporins
activate cell wall autolytic enzymes through blocking terminal cross-linking of peptidoglycan
structure of cephalosporins
beta-lactam ring structure
what is cephalosporins advantage over penicillins
cephalosporins have a R group that increases their resistance to B-Lactamase
what is the prototype first generation cephalosporins
cefazolin
what group is cefazolin in
first generation cephalosporins
what group is cephalexin in
first generation cephalosporins
route of administration of cefazolin
parenteral
route of administration of cephalexin
oral
what do first generation cephalosporins target
- G+; G-
- most G+ cocci are susceptible
what group of cephalosporins can be used for MSSA
first generation cephalosporins
what is the DOC for surgical prophylaxis
Cefazolin (first generation cephalosporin)
what do second generation cephalosporins target
- G+
- increased G- activity
what can second generation cephalosporins not work on
no antipseudomonal activity
what group is cefaclor in
second generation cephalosporins
what group is cefuroxime in
second generation cephalosporins
what group is cefprozil in
second generation cephalosporins
what is the prototype second generation cephalosporins
Cefaclor
which of the second generation cephalosporins can be administered parenterally
Cefuroxime
*the other two are administered orally
which of the cephalosporins are broad spectrum
third generation cephalosporins
what group is ceftriaxone (Rocephin) in
third generation cephalosporins
what group is Cefotaxime sodium (Claforan) in
third generation cephalosporins
which group is Ceftazidime (fortaz) in
third generation cephalosporins
which group is cefixime in
third generation cephalosporins
what is the only third generation cephalosporin that is administered orally
Cefixime
which two third generation cephalosporins are able to penetrate the CNS
- Ceftriaxone
- Cefotaxime sodium
what is the prototype third generation cephalosporins
Ceftriaxone
which organism is Ceftriaxone specifically used against?
Neisseria
what organism is Ceftazidime specifically used against
Pseudomonas Aeruginosa
DOC of N. Gonorrhoeae? When should you not use it though?
Ceftriaxone
*avoid use in neonates, biliruben displacement
what is the one fourth generation cephalosporins
Cefepime (Maxipime)
what is the route of administration of Cefepime?
IV
what does fourth generation cephalosporins (Cefepime) cover?
- antipseudomonal
- better G+ coverage
- Broadest coverage
What is the only “Unnamed” “Fifth” generation cephalosporin
Ceftaroline Fosamil
What is the route of administration of Ceftaroline Fosamil
IV
what does “Unnamed” “Fifth” generation cephalosporin specifically NOT cover
No antipseudomonal activity
what does “Unnamed” “Fifth” generation cephalosporin (Ceftaroline fosamil) cover
MRSA and VRSA
* only beta lactame active against MRSA
DOC for Moraxella catarrhalis
second or third generation Cephalosporins
DOC for Neisseria Gonorrhoeae
Ceftriaxone
DOC for E. coli; Klebsiella; Proteus infection
first or second generation Cephalosporins
DOC for salmonella infection
third generation Cephalosporins
DOC for penicillin resistant Steprococcus pneumoniae
Ceftriaxone
DOC Borrelia Burgdorferi (late disease)
Ceftriaxone
Toxicity of Cephalosporins
- superinfection
- Allergy
- Diarrhea
- Disulfiram-like reaction
- dose dependent renal tubular necrosis
what reaction can occur when a person taking Cephalosporins drinks alcohol
Disulfiram-like reaction
If a patient is allergic to PCN, would you hesitate giving a Cephalosporin
- yes, there is a 10% cross sensitivity with PCN
What is the sole Monobactam drug
Aztreonam (Azactam)
coverage of Aztreonam (Azactam)
- only against aerobic G- (pseudomonas, serratia, klebsiella, proteus)
- no activity against G+
- no cross sensitivity with other B-lactams
What group is Imipenem in
Carbapenems
What group is Meropenem (Merrem) in
Carbapenems
What group is Entrapenem (Invanz) in
Carbapenems
Imipenem must be adminstered with what
Cilastatin
route of adminstration of Imipenem and Meropenem
- IV
coverage of Imipenem and Meropenem
- broad spectrum : anaerobes, G+, G-
what can Imipenem cause that you should be weary of
seizures
DOC for B-lactamase producing Enterobacter infections
Imipenem and Meropenem
MOA of Vancomycin
- prevents transpeptidation of the peptidoglycan chain-binds to the terminal D-ala-D-ala
* cell wall inhibitor that is not a B-lactams
* bactericidal
coverage of Vancomycin
- MRSA
- G+ in PCN-allergic patients
route of administration of Vancomycin when treating superinfections caused by staphylococcus and c-diff
orally
Adverse effects of Vancomycin
- Ototoxic
- Nephrotoxic
- “red man” syndrome: flushing from histamine release (not a hypersensitivity reaction)
mechanism of action of Fosfomycin (Monurol)
inhibits cell wall synthesis at one of the first steps in the synthesis of peptidoglycan-prevents NAG to NAM reduction
coverage of Fosfomycin (Monurol)
- G+
- G-
MOA of Bacitracin
interferes with final dephosphorylation step in the phospholipid carrier cycle; can’t transport NAG-NAM across the inner membrane
coverage of Bacitracin
- G+
- often used in combo with neomycin and polymyxins (G- coverage)
**Neosporin: topical
toxicity of Bacitracin
nephrotoxicity (therefore rarely used parenterally)
