Antibiotics IIa Flashcards
penecillins target what bacterial cell component / process?
cell wall synthesis
cephalosporins target what bacterial cell component?
cell wall synthesis
monobactams target what bacterial cell component / process?
cell wall synthesis
glycopeptides target what bacterial cell component / process?
cell wall synthesis
polypeptides target what bacterial cell component / process?
cell wall synthesis
carbapenems target what bacterial cell component / process?
cell wall synthesis
phosphoenolpyruvates target what bacterial cell component / process?
cell wall synthesis
lipopeptides target what bacterial cell component / process?
cell membrane
detergents target what bacterial cell component / process?
cell membrane
tetracyclines target what bacterial cell component / process?
protein synthesis
aminoglycosides target what bacterial cell component / process?
protein synthesis
macrolides target what bacterial cell component / process?
protein synthesis
sulfonamides target what bacterial cell component / process?
folate synthesis inhibitors / gyrase inhibitors / DNA damage
what are important enzymes in bacterial cell wall building process?
peptidoglycan binding proteins
what is the function of the PBPs?
create bond between NAM-NAG peptidoglycan monomers and NAM-NAG chains
what are the beta lactam compounds?
penicillins
cephalosporins
monobactams
carbapentems
what is the MOA of beta lactam compounds?
bind to and inhibit the PBP enzymes
what is the main adverse effect of beta lactam compounds?
hypersensitivity
more severe hypersensitivity to beta lactam abx would contraindicate use of what other abx?
….beta lactams
penicillin G and V are narrow or broad spectrum?
narrow
ampicillin and amoxicillin are narrow or broad spectrum?
broad
what is the role of clavulanic acid? what is the clinical use?
beta lactamase inhibitor
given in combination with penicillins to increase efficacy
what is the MOA for cephalosporins?
bind to and inhibit PBPs
what is the main adverse effect of cephalosporins?
hypersensitivity
increasing generations of cephalosporins have narrower or broader spectrum?
broader
what class of bacteria represent the narrowest spectrum for cephalosporins?
gram positive cocci
which spectrum of cephalosporins give good CNS penetration?
broader (3rd and 4th generations)
what are the 3rd generation cephalosporins?
ceftriaxone
cefotaxamine
cefdinir
cefixime
what is the 4th generation cephalosporin?
cefepime
what is the MOA of monobactams?
bind to and inhibit PBPs
what is the main adverse reaction for monobactams?
hypersensitivity (not a big risk of anaphylaxis)
what is an important feature of the monobactams?
penetration into CSF
what is the MOA of carbapentems?
bind to and inhibit PBPs
which beta lactam group of abx is beta lactamase resistant?
carbapentems
what is the key adverse effect of carbapentems?
GI - nausea, vomiting, diarrhea
what are the carbapentem compounds?
doripenem
imipenem
ertapenem
meropenem
what is problematic about imipenem? what is used to counteract this problem?
inactivated in the kidney
cilistatin is coadministered to prevent inactivation
what are the three drugs to be considered against MRSA?
vancomycin
vancomycin is what type of abx?
glycopeptide
what is the tissue penetration profile of vancomycin?
good tissue penetration EXCEPT CNS
what is the MOA of vancomycin?
prevents elongation of the peptidoglycan call wall by binding to the D-ala-D-ala pentapeptide and acts as steric inhibitor
what is the main adverse effect of vancomycin?
flushing (red neck or “red man syndrome”)
think skin
what is the MOA of bacitracin?
blocks incorporation of amino acids and nucleic acids into cell wall
what is the main clinical use for fosfomycin?
UTIs in females
what is the MOA of fosfomycin?
blocks an early step in cell wall synthesis by preventing synthesis of UDP-N-acetylmuramic acid
bacitracin is commonly found in what type of preparations?
topical
which two abx block early steps of cell wall synthesis?
fosfomycin
bacitracin
inhibiting protein synthesis is generally bactericidal or bacteristatic?
bacteristatic
what is the general MOA of the protein synthesis inhibitors?
disrupt translation by targeting 50S, 30S subunits needed to translate bacterial mRNA
what is the MOA of the aminoglycosides?
bind to 30S subunit and blocks initiation of step 1
streptomycin, gentamycin, kanamycin, amikacin, tobramycin, and neomycin are what class of abx?
aminoglycosides
what class of abx are used in combination with beta lactam abx to treat serious gram negative infections?
aminoglycosides
what class of abx are used in combination with aminoglycoside abx to treat serious gram negative infections?
beta lactams
what are the key adverse effects of aminoglycosides?
nephrotoxic
ototoxic
erythromycin, clarithromycin, and azithromycin are what class of abx?
macrolides
what is the MOA of the macrolides?
binds the 50S subunit and impairs translocation to the P site (step 4)
what are the key adverse effects of the macrolides?
GI - cramps, nausea, vomiting
what abx are agonists of the motilin receptor in the GI tract?
macrolides
what is the MOA of tetracyclines?
binds to the 30S subunit and prevents binding of new aminoacyl-tRNA to A site (step 2)
what are the key adverse effects of tetracyclines?
nutrient interaction - binds calcium, resulting in growth of calcified tissue - discoloration (bone, teeth)
ecological effects - disrupt normal flora
photosensitivity (skin)
what is a contraindication for tetracycline use?
development (children, pregnant women)
what is the MOA of clindamycin?
binds 50S subunit and prevents formation of initiation complexes (step 1) and translocation to P site similar to macrolides (step 4)
what are the key adverse effects of clindamycin?
GI
