Aminoglycosides Flashcards
What is the main structure of aminoglycosides?
2 amino sugars in glycosidic link to aminocyclitol ring
What are the mechanisms of aminoglycosides?
Through porin channel, down EC gradient
1) inhibit initiation
2) mireading of mRNA (faulty proteins)
3) premature termination (post antibiotic effect)
Are amino glycosides cidal?
Yes!
What do you use aminoglycosides for?
Mostly vs. G-. Used with beta-lactams for synergism
What is the mechanism of synergism between aminoglycosides and beta-lactams?
Increased penetration of the amino glycosides
What do high levels of aminoglycosides in the renal cortex lead too?
Reversible nephrotoxicity
What do high levels of aminoglycosides in the endolymph lead too?
Irreversible ototoxicity
What other side effects can be caused by aminoglycosides?
Degeneratiion of auditory nerve = permanent hearing loss
What are the signs and symptoms of degeneration of the auditory nerve due to ahminoglycosides?
Auditory - tinnitus, high-frequency hearing loss
Vestibular - vertigo, ataxia, loss of balance
What happens when ahminoglycosides accumulate in the fetus?
Ototoxicity in neonates
What are some IV aminoglycosides?
Gentamicin - topical for burns, wounds, catheter infections, ophthalmic
Tobramycin - similar to gentamicin
Amikacin - nosocomial infections resistant to gent & tobra
What are some oral aminoglycosides?
Neomycin - prep for bowl surgery, topical anti-infectant
Paromomycin - amebic dysentery
How often are aminoglycosides given?
Generally 1 x/day b/c significant post-antibiotic effect
Must monitor peaks and troughs 2-3 x/day
What is the cockcroft-gault equation?
((140-age) X (lean wt in kg))/
72 X serum creatinine (mg/dL)
(Women multiply X 0.85)
What is the normal Creatine clearance of a 70kg male?
120-125 ml/min
