Aminoglycosides

Question 1

aminoglycosides are ___________________ at physiologic pH

Answer 1

highly ionized

Question 2

what is the absorption/route like of aminoglycosides?

Answer 2

minimal oral absorption
well absorbed by all parenteral routes

Question 3

what is the distribution of aminoglycosides?

Answer 3

mostly extracellular

Question 4

how are aminoglycosides excreted?

Answer 4

mostly renal filtration and concentrates in urine

Question 5

how do aminoglycosides have a bacteriocidal effect?

Answer 5

protein synthesis inhibition at 30S ribosomal subunit
only protein synthesis inhibitor that is actually bacteriocidal

Question 6

what blocks the oxygen dependent, active uptake at the cytoplasmic membrane of aminoglycosides?

Answer 6

hyperosmolarity
low pH
anaerobic conditions

Question 7

efficacy of aminoglycosides is associated with Cmax plasma concentration _________ the MIC

Answer 7

8-10x

Question 8

what is neomycin commonly used for?

Answer 8

enteric and topical infections

Question 9

what is neomycin too toxic for?

Answer 9

to use parenterally

Question 10

what is Tobramycin used primarily for in veterinary medicine?

Answer 10

ophthalmic infections

Question 11

what are two aminoglycosides that are used systemically and topically?

Answer 11

gentamicin
amikacin

Question 12

how effective is gentamicin against E. coli?

Answer 12

very effective

Question 13

what are the adverse effects of aminoglycosides?

Answer 13

nephrotoxicity
ototoxicity
neuromuscular blockade

Question 14

what is gentamicin’s spectrum in general?

Answer 14

gram negatives

Question 15

what is the most common aminoglycoside toxicity in veterinary medicine?

Answer 15

aminoglycoside nephrotoxicity

Question 16

what is aminoglycoside nephrotoxicity associated with?

Answer 16

prolonged high trough concentrations

Question 17

what does the covalent binding of aminoglycosides to intracellular organelles in the proximal renal tubules mean for food animals?

Answer 17

extra-label use in cattle is suggested at 18 months
highly discouraged from use in food animals

Question 18

how can you reduce the likelihood of aminoglycoside nephrotoxicity?

Answer 18

keep the patient well hydrated
limit other nephrotoxic drugs if possible
perform therapeutic drug monitoring

Question 19

what should you monitor for aminoglycoside nephrotoxicity?

Answer 19

increases in serum BUN or creatinine occur too late to be helpful
perform serial urinalyses: increasing tubular casts, increasing protein, possible increasing specific gravity and glucose

Question 20

should you use increases in serum BUN or creatinine to monitor aminoglycoside nephrotoxicity?

Answer 20

no- increases in serum occur too late to be helpful

Question 21

is it okay to use aminoglycosides on the ears with a ruptured tympanic membrane?

Answer 21

no: ototoxicity, deafness

Question 22

do aminoglycosides ever cross the blood brain barrier?

Answer 22

no- not even with inflammation

Question 23

are aminoglycosides bactericidal or bacteriostatic?

Answer 23

bactericidal

Question 24

can tobramycin be used systemically?

Answer 24

yes

Question 25

what is the four quadrant coverage of gentamycin/aminoglycosides?

Answer 25

E. coli: +++
Staphylococcus: (+)
Streptococcus: -
anaerobe: -

Question 26

what is the spectrum of gentamycin in general?

Answer 26

gram negative

Question 27

in whom is therapeutic drug monitoring more important for aminoglycosides?

Answer 27

geriatric and in animals with conventional divided dosing regimens

Question 28

is aminoglycoside ototoxicity reversible by stopping the drug?

Answer 28

no- often permanent

Question 29

when prescribing an aimonglycoside, what should you check in the ears for?

Answer 29

intact tympanic membrane

Question 30

what drugs used for ears contain gentamycin?

Answer 30

otomax
mometamax

Question 31

can you see ototoxicity with parenteral use of aminoglycosides?

Answer 31

yes

Question 32

what is an aminoglycoside neuromuscular blockade associated with?

Answer 32

high plasma concentrations of aminoglycosides following rapid IV injection or general anesthesia

Question 33

is Pseudomonas easy to get rid of?

Answer 33

highly resistant

Question 34

what is it an indicator of if anitmicrobials are effective against Pseudomonas?

Answer 34

strong gram negative action

Question 35

what is Pseudomonas associated with?

Answer 35

melting corneal ulcers
otitis externa
wounds
pneumonia

Question 36

what are some not topical products that are effective against Pseudomonas?

Answer 36

anti-pseudomonal penicillins
carbapenems
ceftazidime