Penicillins bind to what?
PBP's that normally catalyze transpeptidation reaction.
Penicillin V
Specifically PO.
Half life for Pen G in serum:
30 minutes.
How is nafcillin cleared?
Biliary excretion.
How is oxacillin cleared?
Biliary and kidney.
Are penicillins cross-sensitizing?
Yes! ALL penicillins are cross-sensitizing.
Drug of choice for gram + cocci:
Penicillin G
Drug of choice for syphilis:
Penicillin G
Three penicillinase resistant penicillins:
Methicillin (prototype, but too much nephrotoxicity), oxacillin, and nafcillin.
Two extended spectrum penicillins:
Ampicillin, amoxicillin.
Drug of choice for prophylactic coverage of bacterial endocarditis:
Ampicillin or amoxicillin.
Drug of choice for Proteus mirabilis infections:
Ampicillin.
Two antipseudomonal penicillins:
Ticarcillin and Piperacillin.
First generation cephalosporins:
Cephalexin, cephazolin.
Drug of choice for surgical prophylaxis:
Cephazolin.
Second generation cephalosporins:
Cephaclor, cephoxitin.
Good for anaerobes such as Bacteroides fragilis:
Cefoxitin.
Third generation cephalosporins:
Cefixime, cephotaxime.
Drug of choice for gonorrhea:
Cefixime.
Drug of choice for H. flu:
Cefotaxime.
Fourth generation cephalosporin:
Cefepime
Uses for 1st generation cephalosporins:
PEcK
Proteus mirabilis, E. coli, Klebsiella
Uses for 2nd generation cephalosporins:
PEcK + Haemophilus, Enterobacter, and Neisseria.
Uses for 3rd generation cephalosporins:
Better against anaerobes like Bacteroides fragilis.
Uses for 4th generation cephalosporins:
Broader, but pretty much same as 3rd generation.
Monobactams
Only 1: Aztreonam. Used for aerobic gram negative rods like P. aeruginosa.
Carbapenems
Imipenem + Cilastatin (Have to use cilastatin to block the dehydropeptidase I).
Imipenem binds to what?
PBP-2.
What is the broadest beta lactam antibiotic?
Imipenem
MOA of vancomycin:
Inhibits cell wall synthesis. Replaces D-Ala-D-Ala with D-Lac.
Spectrum of vancomycin:
Only gram + bacteria.
Drug of choice for MRSA sepsis and bacterial endocarditis.
Vancomycin.
How do we treat Strep faecalis?
Vancomycin and an aminoglycoside.