Cell Wall Synthesis Inhibitors Flashcards
1
Q
what are the 5 cell wall synthesis inhibitors
A
- penicillins
- vancomycin
- cephalosporins
- carbapenems
- monobactams
2
Q
substitutions at the R group of a penicillin can modify what 3 properties
A
- increased acid stability in the gut
- minimize bacteria resistance dt penicillinase
- extend spectrum via increased bacterial penetration
3
Q
which 2 penicillins have been modified to have increased gut stability
A
penicillin V
amoxicillin
4
Q
which penicillin has been modified to minimize bacterial resistance due to penicillinase
A
dicloxacillin
5
Q
which penicillin has been modified to extend spectrum via increased bacterial penetration
A
piperacillin
6
Q
what are the 3 stages of bacterial cell wall synthesis
A
- synthesis and assembly of cell wall subunits in the cytosol
- linear polymerization of subunits in cell membrane
- cross-linking of peptidoglycan polymers at the cell wall
7
Q
which 2 abx act on stage 1 of bacterial cell wall synthesis
A
fosfomycin
cycloserine
8
Q
which 2 abx act on stage 2 of bacterial cell wall synthesis
A
bacitracin
vancomycin
9
Q
which 2 abx act on stage 3 of bacterial cell wall synthesis
A
penicillins
cephalosporins
10
Q
abx that inhibit cell wall synthesis are
A
bactericidal
11
Q
vancomycin acts on stage 2 of bacterial cell wall synthesis and targets
A
transglycosylase
12
Q
penicillins and cephalosporins act on stage 3 of bacterial cell wall synthesis and target
A
transpeptidase and carboxypeptidase
→ PBP: penicillin binding proteins
13
Q
production of beta-lactamase is via a __
and is induced in the presence of __
A
plasmid
penicillin
14
Q
what are the 3 beta lactamase enzymes that we need to know
A
- penicillinases → NSBL
- cephalosporinases → ESBL
- carbapenemases
15
Q
penicillinases (NSBL) have no major activity against
A
cephalosporins
carbapenems
16
Q
penicillinases are found in what 3 bacteria
A
- s. aureus
- klebsiella
- e.coli
17
Q
cephalosporinases (ESBL) are commonly found in which class of bacteria
A
gram negative rods
18
Q
name 2 bacteria that contain cephalosporinases
A
- e. coli
- k. pneumoniae
19
Q
cephalosporinases remain sensitive to
A
carbapenems
20
Q
both penicillinases and cephalosporinases can be inhibited by
A
beta-lactamase inhibitors
21
Q
what are the 3 inhibitors of NSBL and ESBL
A
- amox/clauv → Augmentin
- piper/taz → Zosyn
- sulbact/amp → Unasyn
22
Q
what drug inhibits all of the beta lactamases
A
avibactam w. ceftazidime (Avycaz)
23
Q
carbapenemases are also called
A
KPC-NDM-1
24
Q
carbapenemases (KPC-NDM-1) are only inhibited by
A
avibactam w. ceftazidime
25
what 2 main bacteria contain carbapenemases
e. coli
klebsiella
26
what are the 2 types of altered penicillin binding proteins
1. acquisition of new PBP
2. altered structure of existing PBP
27
which type of altered PBP causes resistance to all beta lactam inhibitors
acquisition of new PBP
28
which bacteria is an example of acquisition of a new PBP
staphylococcus spp (MRSA)
29
altered structure of existing PBP causes what type of resistance
gradual increase in resistance to penicillins and cephalosporins
30
what 2 bacteria are examples of altered structure of existing PBP
strep pneumo
neissereia gonorrheae
31
porin channels are found in what class of bacteria
gram negative
32
what is the clinical significance of porin channels
conduit for hydrophilic abx to get inside
33
which bacteria has mutated to alter the structure or # of porin channels to increase resistance
pseudomonas
34
MSSA are resistant to all \_\_\_
due to production of \_\_\_;
with the exception of
penicillins
penicillinase (NSBL)
dicloxacillin
35
MRSA are resistant to all \_\_\_
due to \_\_
beta lactams
alteration of PBP2a
36
MRSA is sensitive to
inhibitors of cell wall synthesis stage 2 → vancomycin
37
what gram positive cocci is penicillin used for
streptococci
s. aureus
enterococci
38
what gram negative cocci is penicillin used for
neisseria meningititis
m. catarrhalis
39
name 4 infxns that streptococci is associated with
1. pharyngitis
2. PNA
3. sinusitis
4. otitis media
40
what 3 penicillins are used for streptococci
Pen G
Pen V
Augmentin
41
enterococci are commonly associated with what 3 infxns
1. bacteremia
2. meningitis
3. UTI
42
what 3 penicillins are commonly used for enterococci
1. Pen G
2. Ampicillin (plus aminoglycoside)
3. Ampicillin
43
what gram negative rods are penicillins used for
e. coli
pseudomonas species
44
e. coli are commonly associated with what 3 infxns
UTI
diarrhea
hemorrhagic colitis
45
what penicillins are used for e. coli
ampicillin
augmentin
46
what penicillin is used for pseudomonas
piperacillin-tazobactam (Zosyn)
47
penicillins are never used for what 3 bacteria
MRSA
neisseria gonorrhea
c.diff
48
what anaerobe is Zosyn used for
bacteroides fragilis
49
oral absorption of penicillins depends on
acid stability
50
oral absorption of Pen G is
poor and unreliable
51
oral absorption of pen v and amoxicillin is
excellent
52
piperacillin and ticaracillin are administered via
IV only
53
IM absorption of penicillins are dependent on
salt form
54
IM absorption of penicillins are rapid in \_\_
and delayed from \_\_
aqueous solutions
suspensions → procaine, benzathine
55
IM suspension penicillin is used against organisms that are susceptible to
low but sustained levels of Pen G → syphilis and endocarditis
56
penicillins are distributed throughout \_\_
and penetrate into cells and tissues \_\_
body water
poorly
57
can penicillins enter inflamed tissues or membranes like CSF, joint, and eye
yes
58
penicillins are excreted 90% by \_\_
and require __ dosing
tubular secretion
renal
59
what are the classes of penicillins
1. prototype penicillins
2. pen g
3. pen v
4. penicillinase (NSBL) resistant penicillins
5. extended spectrum penicillins
6. amoxicillin and ampicillin
7. piperacillin and ticarcillin
60
pen G is powerful and expensive and used
IV for hospitalized pt w. serious infxns
61
prototype penicillins have __ antimicrobial spectrum
narrow
62
pen g is a __ penicillin
prototypical
63
pen V is an __ resistant penicillin
and is absorbed better than \_\_
acid
pen g
64
what is an example of a penicillinase (NSBL) resistant penicillin
Nafcillin
65
penicillinase (NSBL) resistant penicillins are __ susceptible to beta lactamase than cephalosporins
less
66
penicillinase (NSBL) resistant penicillins are __ spectrum
and used against \_\_
narrow
gram (+) cocci
67
extended spectrum penicillins penetrate through \_\_
of \_\_
porins
gram (-) organisms
68
amoxicillin requires __ frequent dosing than ampicillin
and a common side effect is \_\_
less
diarrhea
69
what are the 2 anti pseudomonal penicillins
piperacillin
ticarcillin
70
piperacillin and ticarcillin must be administered
parenterally
71
piperacillin and ticarcillin are useful for pseudomonas and what other 2 infxns
b. fragilis
enterococci
72
pen g is sensitive to \_\_
and \_\_
acid
penicillinase
73
in terms of adverse rxns, penicillins are virtually \_\_
with the exception of
non toxic
hypersensitivity rxns
74
hypersensitivity rxns are __ by pt's
over reported
75
type I penicillin rxns are potentially \_\_
but are \_\_
life threatening
rare
76
what is the most common hypersensitivity rxn related to penicillins
maculopapular rash or morbiliform rash → generally mild and reversible
77
what is a common side effect of penicillins
diarrhea
78
what are the two penicillins most commonly associated w. diarrhea
augmentin
ampicillin
79
first gen cephalosporins have coverage against what class of bacteria
gram (-) AND gram (+)
80
second gen cephalosporins have especially good activity against
gram (-)
81
second gen cephalosporins are commonly used for what type of infxn
respiratory
82
third gen cephalosporins have good __ coverage
and also excellent activity against \_\_
(-)
strep pneumo → (+)
83
relative to penicillins, cephalosporins have (3)
1. broader spectrum against (-) bacteria
2. less susceptibility to NSBL
3. low cross-reactivity in penicillin sensitive pt
84
first gen cephalosporins have good coverage against \_\_\_
so are used frequently for \_\_
and \_\_
MSSA
surgical prophylaxis
skin infxns
85
what 3 (-) rods are 1st gen cephalosporins used for
e. coli
proteus
klebsiella
86
what 2 gram negative infxns are 1st gen cephalosporins indicated in
UTIs
PNA
87
2nd gen cephalosporins have increased __ coverage compared to 1st gen
(-)
88
name 5 gram (-) infxns that 2nd gen cephalosporins are commonly used in
1. PNA
2. UTIs
3. otitis media
4. sinusitis
5. peritonitis
89
3rd gen cephalosporins have best activity against what type of bacteria
but also cover \_\_
(-)
streptococci
90
4th gen cephalosporins are more resistant to
chromosomal and extended spectrum beta lactamases (ESBL)
91
4th gen cephalosporins have good activity against what 2 bacteria
pseudomonas
strep pneumo
92
4th gen cephalosporins cover some anaerobes, but not
b. fragilis
93
5th gen cephalosporin has some \_\_
but better \_\_
(-)
| (+)
94
5th gen cephalosporin has good coverage against (3)
MRSA → can bind to PBP2a
strep pneumo
e. faecalis
95
5th gen cephalosporin has limited __ activity
and no __ coverage
anaerobe
pseudomonas
96
\_\_ stable cephalosporins can be given orally
acid
97
cephalosporins penetrate well into most tissues and fluids, including \_\_
but they do NOT penetrate the \_\_
and CSF
placenta
brain
CSF
98
what cephalosporin does have good CNS penetration
3rd gen → Ceftriaxone
99
cephalosporins are primarily excreted via the \_\_
and do require __ dosing
kidneys
renal
100
no cephalosporins should be given to what pt population
pt w. hx of type 1 immediate sensitivity to penicillin
101
allergy/hypersensitivity rxns to cephalosporins are __ than with penicillins
less severe
102
cephalosporin cross reactivity with penicillins is \_\_
and is greatest with \_\_
\< 1%
1st gen
103
what are 2 adverse rxns related to cephalosporins
1. GI distress
2. superinfxn
104
superinfections are more of a concern with which generations of cephalosporin
2nd and 3rd → broader spectrum
105
all cell wall synthesis inhibitors are
bactericidal
106
vancomycin inhibits stage __ of cell wall synthesis
2
107
vancomycin blocks ___ polymerization
via binding to __ cell wall precursor
glycopeptide
D-alanyl-D-alanine
108
resistance to vancomycin is via
alternative cell wall terminal peptide D-ala-D-lac
109
resistance to vancomycin is __ mediated
plasmid
110
vancomycin resistance is seen almost exclusively in
enterococci (VRE)
111
\_\_ resistance to vancomycin is rare
s. aureus (VRSA)
112
what gram (+) infxns is vancomycin used for
staph/strep
severe skin and soft tissue
meningitis
PNA
endocarditis
sepsis
113
vancomycin is replacing **\_\_**
as first choice against \_\_
metrondiazole
c.diff
114
antibiotic-associated diarrhea (CDAD) is due to
c.diff
115
vancomycin has poor __ absorption,
but is used orally for \_\_
oral
c.diff
116
vancomycin is excreted mainly via the \_\_
and does require __ dosing
kidneys
renal
117
what is the most common adverse rxn associated w. vancomycin
nephrotoxicity
118
nephrotoxicity w. vanco is increased with use of
aminoglycosides
119
redman syndrome is associated with
infusion of vanco
120
ototoxicity with vancomycin is
rare
