Walters - Aminoglycosides Flashcards
____ are amino sugars in glycosidic links to aminocyclitol ring. They are ____ and usually given via IV. They are ___
aminoglycosides; polycations; cidal
what is mechanism for aminoglycosides
Enter periplasmic space of G - bacteria through porin channels down electrochemical gradient. In cell:
- inhibit initiation
- misreading of mRNA –> faulty proteins
- premature termination –> postantibiotic effect
aminoglycosides are ____ effective vs anaerobes bc they don’t use oxygen and don’t create electrochemical gradient.
not
what are aminoglycosides used with for synergism?
beta lactams; increases penetration of amino glycoside
where do aminoglycosides attain their highest levels in
- renal cortex; nephroxicity (reversible)
- endolymph of inner ear; otoxicity (irreversible)
- degeneration of auditory nerve leads to permanent hearing loss.
* oxotoxicity can develop in neonates
what are autitory symptoms
- tinnitus
2. high frequency hearing loss
what are vestibular symptoms
- vertigo
- ataxia
- loss of balance
What are the IV aminoglycosides
- Gentamicin
- Tobramycin
- amikacin
-icin coming from micro mono spora. -mycin come from _____
streptomycins
This amino glycoside is given topical for burns, wounds, catheter infections, or ophthalmic for superficial ocular infections
gentamicin
This amino glycoside is very similar to gentamicin but may have less ototoxicity than gentamicin
tobramycin
this amino glycoside is enemy resistant and is used for ____ infections that resist gentamicin and tobramycin
Amikacin; nocosomial
what are the oral aminoglycosides
- neomycin
2. paromomycin
____ is used to prep for bowel surgery and is a topical anti infectant
neomycin
____ is used to kill cysts of _____ histolytica; an amebic dystentary
paramomycin; entamoeba
aminoglycosides are suppose to be give ____ x a day bc of post antibiotic effect but bc its nephrotic you have to adjust dose for renal function.
1
how do you adjust dose for aminoglycosides
max daily dose x estimated CL cr/normal CLcr
what is the normal creatanine clearance for a 70 kg male
120-125 ml/min
ahminoglycosides are polycations and therefor only distribute in _____ body mass
lean
if your giving it 1 x a day monitor _____. if giving 2-3 x a day monitor ____ and troughs.
troughs; peaks
what are other side effects of ahminoglycosides
can cause neuromuscular block;–> get a higher rate of respiratory paralysis; becomes a problem post op
what is the mechanism of neuromuscular blockage of aminoglycosides
- block Ca+ uptake into cholinergic nerve terminals thus decreasing Ach release and in turn muscle contraction.
- block postsynaptic cholinergic receptors.
how would you treat the neuromuscular block
give Ca+ via IV or give neostigmine which is a acetylcholinesterase inhibitor that inhibits Ach metabolism thus increasing Ach levels resulting in stimulation of respiratory muscles.
You want to avoid aminoglycosides if your patient has ____ ____, because this is autoimmune disease where there is an Ab against the nicotinic receptor at the NMJ creating extreme muscle weakness. Since ahminoglycosides can also block this receptor, they can exacerbate the condition.
mysthenia graves
