Aminoglycoside PK Flashcards
aminoglycs inhibit protein synthesis at ______
30S
aminos are _____-dependent to kill bacteria
dose
T/F amino with increasing doses shows increased time above MIC
true
what is the post antibiotic effect of aminos on gram-neg bacteria?
3-7 hours
are aminos bactericidal or bacteriostatic?
bactericidal
do aminos treat gram pos or gram neg?
both
do aminos exhibit concentration-dpendent or time-dependent killing?
concentration-dependent
what is the site of action of aminos?
30S protein synthesis
do aminos exhibit persisten effects?
yes “PAE”
T/F aminos have good oral bioavailability
false
are aminos safe in pregnancy?
no, can cause congenital deafness
are aminos safe in breastfeeding?
yes
what is the volume of distribution in cystic fibrosis pts for aminos?
0.35 L/kg
as renal function declines, the elimination rate constant _____, and the half life ______
decreases, increases
as renal function increases, the elimination rate constant _____, and the half life ______
increases, decreases
T/F you can predict amino “k” by knowing the creatinine clearance
true
half-life is typically _____ in a patient with cystic fibrosis
shorter
volume of distribution in ascites would be expected to?
increase
what type of toxicity is associated with aminos?
oxotoxicity and nephrotoxicity
what concentrations do we aim for for amikacin?
Cmax over 32
Cmin over 8wh
why are aminos potentially nephrotoxic?
they are polycationic (+) whereas proximal tubule is anionic (-)
how do we monitor for amino induced nephrotoxicity?
rise in SCr, rise in BUN, urinalysis
T/F clinical presentation of amino induced renal failure is extensive non-urine output
false
what is an important risk factor of pt developing ototoxicity when using aminos?
dialysis
what is a rare AE of aminos?
`paralysis
all trough values should be drawn within ____ of next dose
30 minutes
for extended interval dosing, draw random level _______ after initiation of infusion rather than standard peak/trough
8-10 hours
what impact would extending the dose interval (tau) have?
increased efficacy
which of the following is true?
a. aminos exhibit concentration-dependent killing; however, the upper limit of Cmax is unknown
b. aminos have a concentration-dependent post-antibiotic effect. the higher the Cmax the longer the PAE
c. aminos exhibit adaptive resistance
d. all of the above
d
which if the following is true?
a. in bacteria, exposure to AG causes down-regulation of uptake (adaptive resistance) which can be overcome by EID
b. on the other hand, uptake of AG into renal tubular cells is saturable, therefore if we increase the dose and increase Cmax with EID, then we can maximize efficacy and minimize toxicity
c. EID may provide a period of aminoglycosides to leach back into the renal tubular lumen (for renal excretion), thus minimizing toxicity
d. all are true
d
safety and efficacy parameters for aminos?
safety:
12h tobramycin level
nephrotoxicity (kidney fxn tests): BUN, SCr, CLCR, urine output
ototoxicity
dizziness, imbalance
efficacy:
WBC resolution of leukocytosis
vitals: temp, BP, HR, RR
negative cultures
pulmonary function
