Protein Synthesis Inhibitors Flashcards
1
Q
what are the 4 protein synthesis inhibitors
A
- macrolides
- tetracyclines
- clindamycin
- aminoglycosides
2
Q
macrolides selectively bind the __ ribosomal subunit
and block translocation of ___
A
50s
peptidyl tRNA
3
Q
macrolides are __
but are not __
and enter by
A
bacteriostatic
actively transported
passive diffusion
4
Q
macrolides are a weak __
that are more active at an __ pH
A
base
alkaline
5
Q
resistance to macrolides is via
A
methylation of 23s rRNA of 50s ribosome
6
Q
what gene prevents macrolide binding
A
ermB
7
Q
rates of resistance to macrolides is increasing for what 2 bacteria
A
strep pneumo
h.flu
8
Q
how is strep pneumo developing resistance to macrolides
A
via multi drug efflux transporter
9
Q
what gene is associated with strep pneumo resistance to macrolides
A
mefA
10
Q
all macrolides cover
A
(+) cocci → staph (including MRSA/MSSA), strep
(-) cocci → m. catarrhalis
11
Q
which macrolide covers corynebacterium diptheriae
A
erythromycin
12
Q
which macrolide covers chlamydia
A
azithromycin
13
Q
all macrolides cover which atypical bacteria
A
mycoplasma pneumoniae
14
Q
macrolides do not work well for what infxn
A
UTIs
15
Q
which gram negative bacilli do all macrolides work against
A
bortadella pertussis
16
Q
azithromycin is good for what 4 gram (-) bacilli
A
h.flu
bortadella pertussis
legionella
c. jejuni
17
Q
clarithromycin is good for what 2 gram negative bacilli
A
h. flu
h. pylori
18
Q
what abx is used for neisseria gonorrheae
A
ceftriaxone
19
Q
what abx are used for chlamydia trachomatis and mycoplasma hominum
A
azithromycin/doxycycline
20
Q
what abx is used for trichomonas
A
metrondiazole
21
Q
azithromycin should be taken
A
on an empty stomach
22
Q
clarithromycin can be taken
A
without any regard to meals
23
Q
erythromycin absorption
A
varies depending on salt form
24
Q
free base erythromycin is
A
destroyed by stomach acid
25
stearate erythromycin is
acid-resistant and well absorbed
26
\_\_ erythromycin is better abosrbed
than __ erythromycin
stearate
free base
27
azithromycin and clarithromycin accumulate in \_\_
in the (5)
skin
lungs
tonsils
cervix
sputum
28
macrolides have ___ distribution,
including to the \_\_
wide
fetus
29
macrolides do not distribute as widely to the \_\_
and \_\_
brain
CSF
30
azithromycin is not metabolized and is excreted via the \_\_
liver
31
azithromycin has high tissue penetration and binding with slow release and may be dosed \_\_
daily
32
clarithromycin is __ and excreted
via the \_\_
so __ dosing may be necessary
metabolized
kidneys
renal
33
erythromycin is metabolized in the \_\_
and excreted in \_\_
liver
bile
34
all the macrolides are excreted via the liver except for
clarithromycin
35
what are 2 adverse effects of macrolides
1. GI disturbances
2. prolonged QT interval
36
which macrolide directly stimulates gut motility
erythromycin
37
which 2 macrolides inhibit CYP450
clarithromycin
erythromycin
38
in what cardiac pt population should you use macrolides cautiously
ventricular arrhythmias
39
relative to erythromycin, clarithromycin has
greater duration of activity
40
tetracyclines bind __ and
prevent access of \_\_\_
30s ribosome
aminoacyl tRNA to mRNA site
41
how do tetracyclines inhibit bacteria
bacteriostatic
42
how are drugs resistant to tetracyclines
insertion of MDR transporters that move drug out of the cell
43
MDR plasmid is associated with
tetracyclines
sulfonamides
aminoglycosides
macrolides
44
which tetracycline is not affected by ribosomal protection of proteins that block tetracycline
tigecycline
45
most gram negative cocci and gram negative rods are
resistant to tetracyclines
46
which tetracycline can be used against bacillus anthracis
doxycycline
47
which tetracycline can be used against atypical organisms, including chlamydia and mycoplasma pneumoniae (CAP)
doxycycline
48
which tetracyclines are used against p. acnes
minocycline
doxycycline
49
which tetracyclines are used against chlamydia trachomatis and mycoplasma hominum
azithromycin
doxycycline
50
which tetracyclines have 95-100% bioavailability
doxycycline
minocycline
51
which macrolide has incomplete absorption and is best given on an empty stomach
tetracycline
52
which tetracycline alters intestinal flora and contributes to superinfections
tetracycline
53
tetracycline absorption is impaired by
cations → form salts that can't be absorbed
dairy
54
penetration of tetracyclines into most tissues-fluids is \_\_,
including \_\_
excellent
placental and fetal
55
excretion of doxycycline and minocycline is concentrated in the \_\_
and secreted into \_\_
liver
bile
56
tetracycline is excreted into \_\_
and should be avoided in pt's with __ dz
urine
renal
57
which tetracyclines are long acting
doxycycline
minocycline
58
which tetracycline is short acting
tetracycline
59
what is the main 2 adverse rxn of tetracyclines
teeth and bone
60
tetracyclines should be avoided in what 2 pt populations
later half of pregnancy
children \< 8 yo
61
tetracyclines are a pregnancy risk factor \_\_
D
62
GI disturbance is more common in which tetracycline
tetracycline → not as well absorbed as the other 2
63
besides GI disturbance and teeth/bone, what are 2 other adverse rxns of tetracyclines
1. candidal overgrowth → thrush and vaginitis
2. photosensitivity
64
what 2 drugs do tetracyclines react with
antacids
iron supplements
65
phenytoin, barbituates, and carbamazepine can caused increased absorption of which tetracycline
doxycycline
66
the regimen of choice for tx of urogenital gonorrhea is
IM ceftriaxone and oral azithromycin
67
clindamycin binds to \_\_
and prevents translocation of \_\_\_
to prevent
50s ribosome
peptidyl tRNA (ECN binding site)
peptide bond formation
68
clindamycin is \_\_\_
but can be __ against certain organisms at higher concentrations
bacteriostatic
bactericidal
69
clindamycin is ineffective against which anaerobe
c.diff
70
clindamycin is a good alternative for streptococci and MSSA if a pt is
PCN allergic
71
clindamycin has good coverage against \_\_
for intraabdominal and brain abscesses
bacteroides fragilis
72
\_\_% of clindamycin is orally absorbed
and absorption is not \_\_
90%
affected by food
73
clindamycin penetrates __ especially well
but not \_\_
bone
CSF
74
clindamycin is metabolized by the \_\_
and has __ excretion
liver
biliary
75
is renal dosing required for clindamycin
no
76
is clindamycin excreted in breast milk
yes
77
what common adverse rxn's are associated w. clindamycin (3)
1. nausea
2. diarrhea
3. skin rashes
78
what serious side effect is associated w. clindamycin
pseudomembranous colitis → toxigenic c. diff
79
amiinoglycosides bind \_\_\_
to __ and alter interaction of mRNA with subunit
irreversibly
30s
80
name 3 MOA for aminoglycosides
1. produce inhibition of protein synthesis
2. break up polysomes
3. misread the code → produce lethal proteins
81
how do aminoglycosides kill bacteria
bactericidal
82
aminoglycosides require \_\_
and are not effective against \_\_
O2
anaerobes
83
what is the method of resistance against aminoglycosides
chemical modifications of aminoglycosides that impair ribosomal binding and drug reuptake
84
\_\_ mediated transfer of AG modifying enzymes
is of major importance to \_\_
plasmid
gram (-) pathogens
85
gentamicin, tobramycin, and amikacin have good activity against what 2 gram negative rods
pseudomonas
e. coli
86
if combined with a \_\_
aminoglycosides have good activity against \_\_
cell wall synthesis inhibitor
enterococci
87
gentamicin plus \_\_
work well against \_\_
cell wall inhibitor (PCN or vanco)
enterococci
88
aminoglycosides are high \_\_
and are not well absorbed via \_\_
polar
oral administration
89
aminoglycosides have rapid and complete absorption via __ administration,
and have peak plasma concentrations in \_\_
IM
30-90 minutes
90
aminoglycoside distribution in the body is limited to
extracellular fluid
91
aminoglycoside distribution is excluded from the \_\_
CNS
92
aminoglycosides selectively accumulate in the \_\_
and the \_\_,
predisposing these areas to \_\_
renal cortex
inner ear
toxicity
93
aminoglycosides are eliminated via the \_\_
and have a normal half life of \_\_
kidneys
2-3 hours
94
aminoglycosides require __ dosing
renal
95
is once daily dosing possible for aminoglycosides
yes
96
what is concentration dependent killing
greater plasma concentration kills greater proportion of bacteria at a faster rate → seen with aminoglycosides
97
what is a postantibiotic effect
bactericidal effect persists beyond plasma half-life
98
what 2 properties of aminoglycosides allow for daily dosing
1. concentration dependent killing
2. postantibiotic effect
99
with aminoglycosides, __ levels predict efficacy
and __ levels predict toxicity
peak
trough
100
what is a trough level
time above threshold
101
what irreversible auditory adverse rxn is associated with aminoglycosides
8th CN damage
102
8th CN damage related to aminoglycosides can cause \_\_
and \_\_
tinnitus
vestibular → dizzy, n/v, vertigo
103
what drug potentiates ototoxicity of aminoglycosides
loop diuretics
104
can aminoglycosides cause renal toxicity
yes
105
what is the earliest sign of aminoglycoside-induced nephrotoxicity
increased blood creatinine
106
aminoglycosides are not effective against __ bacteria
(+)
