Exam 2 - Aminoglycosides Flashcards
what is the GP coverage of aminoglycosides
Enterococcus spp. (gent or strepto)
MSSA, MRSA
NEVER USES ALONE
what is the GN coverage of aminoglycosides
Pseudomonas Aeruginosa
A,P>T>G
what is the aminoglycoside that does not cover pseudomonas aeruginosa
streptomycin
Gent and Tobra peak and trough for moderate infections (UTI)
peak: 4-6
trough: 1
Gent and tobra peak and trough for moderate to severe infections (soft-tissue, bacteremia)
peak: 6-8
trough: 1
gent and tobra peak and trough for severe infections (pneumonia, burns, life threatening)
peak: 8-10
trough: 1
gent peak and trough for gram positive
peak: 3-5
trough: 1
describe the strategy for extended dosing
use larger doses once daily to obtain high peaks and undetectable troughs. this strategy relies on the PAE
what is the extended dose for gent and tobra
5-7 mg/kg as a single daily dose
what is the extended dose for amikacin
15-25 mg/kg as a single daily dose
what is the cavoite for using extended dosing
Renal function must be good
CrCl > 40-50
gent and tobra peak and trough for GN extended dosing
peak: 13-20
trough: < 0.5
what are the clinical uses of ami,gent,tobra
serious infections including pseudomonas
what are the clinical uses or gent or strepto
serious infections due GP bugs like enterococci, viridans, or staphylococci
what is the moa of aminoglycosides
irreversibly bind to the 30S subunit
what kind of killers are aminoglycosides
rapidly bactericidal in a concentration dependent manner
what is the resistance against aminoglycosides
alteration in uptake
synthesis of aminoglycoside-modifying enzymes
alteration of binding site (only affects streptomycin)
what is the most important factor that affects aminoglycoside dosing
volume of distribution and clearance
absorption of aminoglycosides
peak within 30-120 min
given IV or IM
CI for IM admin of aminoglycosides
hypotension or critically ill
how is aminoglycoside distributed
primarily in extracellular fluid compartments
where do aminoglycosides distribute POORLY
CSF, sputum, adipose tissue
what weight should be used for aminoglycoside dosing
IBW or ABW if obese
what is the normal Vd
0.25 L/kg
what is the dehydration Vd
0.15-0.2 L/kg
what is the edema Vd (ascites, pregnancy, burn, CHF)
0.3-0.35 L/kg
what is the Vd for neonates/infants
0.5 L/kg
elimination of aminoglycosides
eliminated via the kidney
does hemodialysis remove aminoglycosides
yes, give dose after HD
when to obtain peaks for aminoglycosides
standard: 30 min after 30 min infusion
extended: 60 min after 60 min infusion
when to obtain troughs for aminoglycosides
30 min prior to next dose
what aminoglycosides have serum conc measuring
Gentamicin
Tobramycin
Amikacin
what are the adverse effects of aminoglycosides
Nephrotoxicity
Ototoxicity
what AEs of aminoglycosides are reversible and what are irreversible
nephrotoxicity: reversible if caught early
ototoxicity: irreversible MUST catch early
what is a risk factor for nephrotoxicity
prolonged high trough concentrations
prolonger therapy
what is a risk factor for ototoxicity
prolonged therapy
