Cell Wall Synthesis Inhibitors Flashcards
Which form of penicillin is IV
Penicillin G
Which form of penicillin is oral
Penicillin V
What is the mechanism of penicillin
Bind penicillin binding proteins (transpeptidases)
Block transpeptidase cross linking of peptidoglycan
What is penicillin used for
Mostly used for gram + organisms
Also used for neisseria meningitidis, treponema pallidum, and syphilis
Is penicillin penicillinase resistant
No
What are some toxicities to penicillin
Hypersensitivity reactions
Hemolytic anemia
What is the resistance to penicillin
B-lactamases cleave B-lactam ring
Why are oxacillin, nafcillin, and dicloxacillin penicillinase resistant
Bulky R groups that block access of B-lactamases to B-lactam ring
What are oxacillin, nafcillin, and dicloxacillin used for
S. aureus
“Use NAF for STAPH”
What is in the R group of ampicillin and amoxicillin
Amino group
What are ampicillin and amoxicillin used for
Extended spectrum (more gram - coverage) Haemophilus E. coli Listeria Proteus Salmonella Shigella Enterococci
What are ticarcillin and piperacillin used for
Pseudomonas and gram (-) rods
What is the mechanism of cephalosporins
B-lactam drug that inhibit cell wall synthesis
Less susceptible to penicillinases
What organisms are not covered by cephalosporins
Listeria, Atypicals (chlamydia, mycoplasma), MRSA, and Enterococci
“LAME”
What cephalosporin generation are cefazolin and cephalexin
1st generation
What are 1st generation cephalosporins used for
Gram positive cocci
Proteus mirabilis, E. coli, Klebsiella pneumoniae
“PEcK”
What cephalosporin generation are cefoxitin, cefaclor, and cefuroxime
2nd generation
What are 2nd generation cephalosporins used for
Gram positive cocci
Haemophilus influenzae, Enterobacter, Neisseria spp
Proteus mirabilis, E. coli, Klebsiella pneumoniae, Serratia marcescens
“HEN PEcKS”
What cephalosporin generation are ceftriaxone, cefotaxime, ceftazidime
3rd generation
What are 3rd generation cephalosporins used for
Serious gram (-) infection resistant to other B-lactams Crosses BBB (meningitis)
What cephalosporin generation is cefepime
4th generation
What are 4th generation cephalosporins used for
Increased activity against Pseudomonas and gram (+) organisms
What is the mechanism of aztreonam
Prevents peptidoglycan cross linking by bindind to PBP3
Resistant to B-lactamases
What is aztreonam used for
Gram - rods only
What is special about carbapenems (imipenem and meropenem)
Highly resistant to B-lactamases
What is imipenem administered with and why
Cilastatin (inhibitor of renal dehydropeptidase I)
Decreases inactivation of drug in renal tubules
What is an advantage of meropenem to imipenem
Reduced risk of seizures and stable to dehydropeptidase I
What are carbapenems used for
Gram positive cocci, gram negative rods, anaerobes
What are some toxicities to carbapenems
GI distress
Skin rash
CNS toxicity
What is the mechanism of vancomycin
Inhibits cell wall peptidoglycan formation by binding D-ala D-ala
What is vancomycin used for
Gram positives only
Serious multidrug resistant organisms
MRSA, C. difficile, enterococci
What are some toxicities to vancomycin
Nephrotoxicity, Ototoxicity, Thrombophlebitis, red man syndrome
“NOT the RED VAN”
What is the mechanism of resistance to vancomycin
Amino acid change of D-ala D-ala to D-ala D-lac
