Aminoglycosides/Broad Spectrum Abx (Lec 15)

Question 1

Aminoglycoside Abx structure?

Answer 1

Have amino surgar in glycosidic link

Polar (polycations)

Question 2

Aminoglycoside polarity responsible for what?

Answer 2

pharmacokinetic properties

Question 3

Aminoglycoside mechanism of action?

Answer 3

irreversibly inhibit protein synth:
block initiation of mRNA translation,
bactericidal

Question 4

Aminoglycosides req what for activation?

Answer 4

aerobic conditions,

O2 req for abx transport to 30S subunit

Question 5

Aminoglycoside active against?

Answer 5

aerobic G- enteric rods

Question 6

Aminoglycosides are drug class of choice for what conditions?

Answer 6

sepsis

endocarditis

Question 7

Streptomycin (aminoglycoside) used to treat?

Answer 7

b. plague
TB
endocarditis (in combo therapy)

Question 8

Aminoglycosides + antipseud PCN used to treat what?

Answer 8

p. aeruginosa

Question 9

Neomycin (aminoglycoside) used to treat?

Answer 9

G- skin infections

topical application

Question 10

Gentamicin (aminoglycoside) used to treat what?

Answer 10

tularemia

Question 11

DOC for Enterococci (G+ cocci)?

Answer 11

aminoglycoside + PCN

Question 12

Aminoglycosides are what-dependent killers?

Answer 12

Concentration-dependent:

↑ concentration of drug kills more bacteria at more rapid rate

Question 13

Aminoglycoside post-abx effect?

Answer 13

stays active beyond measurable [ ]

Question 14

Aminoglycoside toxicity?

Answer 14

ototoxic
nephrotoxic

large dose less toxic than multiple small doses

Question 15

Aminoglycoside administration?

Answer 15

IM
IV
topical

NOT oral - GI can’t absorb

Question 16

Aminoglycosides are used primarily how?

Answer 16

in combo w/ other abx

Question 17

3 types of Broad Spectrum Abx (BSA)?

Answer 17

1) chloramphenicol
2) tetracyclines
3) glycylcyclines

Question 18

Chloramphenicol (BSA) mechanism of action?

Answer 18

reversibly binds 50S, preventing peptide bonds ->
inhibits protein synth

*also inhibits mitochondrial protein synth

Question 19

Chloramphenicol is -static or -cidal?

Answer 19

bacteriostatic

can be -cidal to mengeal pathogens

Question 20

Chloramphenicol spectrum?

Answer 20

G-, G+, aerobic, anaerobic, atypical

Question 21

Chloramphenicol used only in what cases?

Answer 21

Life threatening infections

NEVER DOC

Question 22

Chloramphenicol would be used to treat what life threatening infections?

Answer 22

typhoid fever

meningitis

Question 23

Chloramphenicol administered how?

Answer 23

parenteral

Question 24

What is Chloramphenicol not administered orally?

Answer 24

causes aplastic anemia

Question 25

Chloramphenicol distribution?

Answer 25

ALL tissues | CNS penetration

Question 26

Chloramphenicol metabolized how?

Answer 26

Conjugated w/ glucuronic acid in liver

Question 27

Chloramphenicol toxicity (dose-dependent)?

Answer 27

bone marrow suppression | can be reversed by stopping med

Question 28

Chloramphenicol toxicity (dose-independent)?

Answer 28

fatal aplastic anemia

Question 29

Chloramphenicol toxicity to newborns?

Answer 29

Gray Baby Synd: | inadequate glucuronyl transferase activity in liver

Question 30

What enzyme causes Chloramphenicol resistance in bacteria?

Answer 30

acetyl transferase

Question 31

Tetracyclines (BSA) mechanism of action?

Answer 31

reversibly binds 30S ribosome, blocking tRNA attachment-> | inhibits proetin synth

Question 32

Tetracyclines are -static or -cidal?

Answer 32

bacterostatic

Question 33

Tetracyclines spectrum?

Answer 33

G-, G+, aerobic, anaerobic, atypical

Question 34

3 organisms resistant to Tetracyclines?

Answer 34

1) b. fragilis 2) proteus 3) pseudomonas

Question 35

Tetracyclines is DOC for?

Answer 35

``` cholera m. pneumonia chlamydia b. burgdorferi (Lyme, early) vibrio rickettsii (Rocky Mnt Spotted) ```

Question 36

Tetracycline resistance U from?

Answer 36

efflux pumps

Question 37

Tetracyclines administration?

Answer 37

oral | chelation

Question 38

Tetracyclines distribution?

Answer 38

all tissues except joints and CNS Deposit in bone and teeth (chelate Ca2+)

Question 39

Doxycycline (TCN family) metabolized?

Answer 39

NOT in liver | excreted thru feces

Question 40

Tetracyclines side effects?

Answer 40

GI | bone/teeth

Question 41

Glycylcycline (BSA) prototype drug?

Answer 41

Tigecycline

Question 42

Tigecycline method of action?

Answer 42

binds 30S | bacteriostatic

Question 43

Tigecycline spectrum?

Answer 43

same as TCN | AND also active against MRSA, MRSE, PRSP, VRE

Question 44

Tigecycline primarily used to treat what type of infections?

Answer 44

complicated skin and skin-structure, | complicated intra-abdominal

Question 45

Tigecycline administration?

Answer 45

IV

Question 46

Tigecycline elimination?

Answer 46

2/3 fecal | 1/3 renal

Question 47

Tigecycline side effects?

Answer 47

similar to TCN