Lec 5 Aminoglycosides/Macrolides Cushman Flashcards

(48 cards)

1
Q

aminoglycoside 2 core structures

A

streptidine
2-deoxystreptamine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

which of the following are NOT aminoglycosides? (2 of them)

a. tobramycin
b. erythromycin
c. plazomicin
d. amikacin A
e. clarithromycin
f. gentamicin C2
g. neomycin B
h. streptomycin

A

b. erythromycin
e. clarithromycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

4 main things for mechanism of aminoglycosides

A

-inhibits formation of initiation complex
-blocks further translation
-premature termination of transcription
-impairment of proofreading and formation of “nonsense proteins”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

aminoglycosides bind to the ____ subunit of the ribosome

A

30S

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what do the “nonsense proteins” formed by aminoglycosides do?

A

impair bacterial cell wall function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

aminoglycoside antibiotics can affect the 30S ribosomal subunit to cause a _______ mutation

A

frameshift

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

which class of antibiotics affects normal codon-anticodon binding?

A

aminoglycosides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

bacterial aminoglycoside uptake: passage through the cytoplasmic membrane is an _______ transport process

A

active

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

bacteria inactivate aminoglycosides by all of the following EXCEPT

a. acetylation
b. adenylation
c. phosphorylation
d. oxidation

A

d. oxidation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

3 aminoglycoside resistance mechanisms

A
  1. metabolism
  2. altered ribosomes
  3. altered uptake
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

aminoglycoside resistance: the ___ rRNA binding site can be altered through point mutations, observed clinically with mycobacterium tuberculosis

a. 16S
b. 30S
c. 50S
d. 70S

A

a. 16S

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

which is TRUE about the toxicity of all aminoglycosides?

a. ototoxicity and nephrotoxicity are reversible
b. ototoxicity is reversible; nephrotoxicity is irrev
c. ototoxicity is irrev; nephrotoxicity is reversible
d. ototoxicity and nephrotoxicity are both reversible

A

c. ototoxicity is irrev; nephrotoxicity is reversible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

T or F: serial audiograms are recommended with aminoglycosides

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

aminoglycosides concurrent use with _____ _____ or vanc can potentiate nephrotoxicity (answer is a drug class)

A

loop diuretics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

respiratory paralysis from aminoglycosides can usually be reversed with _______ or calcium gluconate

a. probenecid
b. vancomycin
c. neostigmine
d. meclizine

A

c. neostigmine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

aminoglycosides have broad spectrum activity, but in practice they are almost always reserved for gram _______

A

negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

how can penicillins and aminoglycosides be given together?

A

administered in different compartments (one in each arm) to avoid chemical rxn between the classes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

penicillin/aminoglycoside combinations are used to treat

a. bacterial endocarditis
b. tuberculosis
c. UTIs, burns, some pneumonias, joint and bone infections

A

a. bacterial endocarditis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

streptomycin is most often used to treat

a. bacterial endocarditis
b. tuberculosis
c. UTIs, burns, some pneumonias, joint and bone infections

A

b. tuberculosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

gentamicin use

a. bacterial endocarditis
b. tuberculosis
c. UTIs, burns, some pneumonias, joint and bone infections

A

c. UTIs, burns, some pneumonias, joint and bone infections

21
Q

most important aminoglycoside

22
Q

which aminoglycoside is used to treat nosocomial infections (hospital-acquired)?

a. tobramycin
b. plazomicin
c. amikacin
d. gentamicin
e. neomycin
f. streptomycin

23
Q

Amikacin A’s important moiety that inhibits bacterial metabolism by R-factors

a. L-arginine
b. syn-methoxyether
c. L-hydroxyaminobuterylamide
d. C-6 hydroxyl

A

L-hydroxyaminobuteryl amide

24
Q

tobramycin is adenylated at ___ and acetylated at ___

25
_______ has superior activity vs. Pseudomonas aeruginosa than Amikacin, it is widely used parenterally to treat gentamicin-resistant Pseudomonas aeruginosa infections
tobramycin
26
2 orally used aminoglycosides
neomycin B paromomycin
27
two aminoglycosides used clinically to suppress gut flora in travelers diarrhea and prophylactically prior to GI surgery to dec the incidence of peritonitis
neomycin and paromomycin
28
__________ is used to treat amoebic dysentery as well as dwarf tapeworm and beef tapeworm a. paromomycin b. gentamicin c. streptomycin d. erythromycin
a. paromomycin
29
first antibiotic used to cure tuberculosis
streptomycin
30
skipped plazomicin and streptomycin
ok
31
macrolides are usually ___-membered lactone rings
14
32
drugs ending in "mycin" comes from ? a. streptomyces b. micromonospora
a. streptomyces
33
drugs ending in "micin" comes from ? a. streptomyces b. micromonospora
b. micromonospora
34
which sugar of macrolides is most important for activity? a. desosamine sugar b. cladinose sugar c. pentose sugar
a. desosamine sugar (b. is less important, c. is not on the structure)
35
Macrolides are polyketides because they are produced by sequential addition of _______ groups to a growing chain. This results in _______ groups on alternate carbon atoms in the macrolide ring.
propionate methyl
36
The pKa of the amine in erythromycin is ___. The amine can form salts that are more soluble
8.8
37
Macrolide binding mainly involves the bacterial ___ RNA and not the protein
23S (part of 50S)
38
4 resistance mechanisms for macrolides
1. Lactone ester hydrolase induced to degrade the macrolides by hydrolysis of the macrocycle 2. A2058 methylation 3. Mutation of A to G in A2058 4. An efflux pump ejects drugs from cell by an active transport process
39
Certain organisms like Pseudomonas spp. and Enterobacter spp. exhibit _______ _______ by not allowing entry of macrolide antibiotics
intrinsic resistance
40
erythromycin derivative that is stable in acid due to 6-OCH
clarithromycin
41
amine analog, acid stable, N-methylated methyleneamino moiety replaces C-9 ketone a. erythromycin b. clarithromycin c. azithromycin
c. azithromycin
42
main route of erythromycin metabolism is _________ in the liver
demethylation
43
erythromycins are primarily used for infections of skin and soft tissues primarily caused by gram ______ bacteria
positive
44
clinical use of erythromycins look at that
okay
45
long term use (10-20) days of macrolides can induce a reversible _______ _______ a. pseudomembranous colitis b. cholestatic hepatitis c. aplastic anemia d. tendon rupture
b. cholestatic hepatitis
46
how is clindamycin metabolized?
CYP P450
47
erythromycin can inc the probability of _______ _______ a. pseudomembranous colitis b. cholestatic hepatitis c. aplastic anemia d. pyloric stenosis
d. pyloric stenosis
48
why is oral erythromycin given as enteric coated or as more stable salts or esters?
it is inactivated by gastric acids