micro - antimicrobials Flashcards
inhibiting peptidoglycan cross-linking –> block cell wall synthesis
penicillin, methicillin, ampicillin, piperacillin
cephalosporins, zaztreonam, imipenem
block peptidoglycan synthesis
bacitran and vancomycin
inhibit folic acid synthesis (methylation) –> block nucleotide synthesis
sulfonamides, trimethroprim
block DNA topoisomerase
fluoroquinolones
block mRNA synthesis
rifampin
damage DNA
metronidazole
block protein synth at 50S ribosomal unit
chloramphenicol, clindamycin, linezolid, macrolides, streptogramins (-pristin)
block protein synth at 30S ribosomal unit
aminoglycosides, tetracycline
macrolides MOA
block 50S
penicillin general
prototype beta lactam, blocks peptidoglycan cross linking - inhibits cell wall synthesis
penicillin MOA
binds penicillin-binding protein (transpeptidases) –> block transpeptidase cross-linking of peptidoglycan
activate autolytic enzymes
penicillin clinical use
gram positive organisms - strep pneumo, strep pyogenes, actinomyces
neisseria meningitis, treponema pallidum, syphilis
penicillin toxicity
hypersensitivity rxn
hemolytic anemia
penicillin resistance
beta-lactamase cleaves beta-lactam ring
penicillin G
IV and IM form
penicillin V
oral
penicillin bactericidal vs.
gram positive cocci and rods, gram negative cocci, and spirochetes
penicillinase-resistant penicillins
NOD IF U RESIST
nafcillin, oxacillin, dicloxacillin
PRP MOA
same as penicillin - bind PBP (transpeptidase) -> inhibit transpeptidase crosslinking of peptidoglycan –> inhibit cell wall synthesis
narrow spectrum!
PRP MOA of resistance to penicillinase
bulky R group blocks access of beta-lactamase to beta-lactam group
which PRP used for staph
nafcillin
PRP clinical use
staph aureus (except MRSA)
MRSA resistance MOA
altered penicillin binding protein target site
PRP toxicity
hypersensitivty rxn
interstitial nephritis
aminopenicillins
ampicillin and amoxicillin
aminopenicillins MOA
same as penicillin *bind penicillin binding protein (transpeptidases) –> inhibit transpeptidase crosslinking of peptidoglyan –> inhibit cell wall synthesis
wider spectrum!
aminopenicillin with greater oral bioavailability
amoxicillin
aminopenicillin clinical use
extended spectrum penicillin (AMPED UP) - HELPSS kill enterococci
h flu, e coli, listeria monocytogenes, proteus mirabilis, salmonella, shigella, enterococci
aminopenicillin toxicity
hypersensitivity rxn, ampicillin rash, pseudomembranous colitis
aminopenicillin resistance
beta lactamase cleaves beta lactam ring ***add CLAVULANIC acid to help protect
antipseudomonals
ticarcillin, pipercillin
antipseudomonals MOA
same as penicillin - extended spectrum
antipseudomonals clinical use
pseudomonas and gram negative rods
suscept to beta-lactamase –> use with beta-lactmasease inhibitors
antipseudomonals toxicity
hypersensitivity rxn
beta lactamse inhibitors
CAST - clavulanic acid, sulbactam, tazobactam
often added to penicillin antibiotics to protect antibiotic from destruction by beta-lactamase
cephalosporins MOA
beta lactam - block peptidoglycan cross linking –> inhibit cell wall synthesis **lessss susceptible to beta-lactamase
bactericidal
not covered by cephalosporins
LAME = listeria, atypicals (chlamydia/mycoplasma), MRSA and enterococci
which cephalosporin blocks MRSA
ceftaroline
cephalosporins 1st generation
cefazolin, cephalexin
cephalosporins 1st generation bugs
PEcK - gram positive cocci, proteus mirabilis, e coli, klebsiella pneumoniae
what is used prior to surgery to prevent staph aureus wound infections
cefazolin