Protein Synthesis Inhibitors Flashcards
What are the protein synthesis inhibitors?
AT CELLS
Aminoglycosides
Tetracyclines
Chloramphenicol
Erythromycin
Lincosamines
Linozelid
Streptogramins
what are the aminoglycosides?
GNATS KN
Gentamycin
Neomycin
Amikacin
Tobramycin
Streptomycin
Kanamycin
Netilmycin
how do aminoglycosides work?
bind to 30s subunit and block the initiation complex and cause misreading of mRNA
what is the mechanism of resistance needed to evade aminoglycosides?
- Impaired penetration into the cell through porin channels: Strep and Enterococci
- Altered receptor in subunit 30s
- production of transferace enzyme by bacteria
how are aminoglycosides administered?
is it better to adminster aminoglycosides in little doses or a lot in 1 dose?
Does it target aerobic, anaerobic or both type of bacteria?
parentally (IV or IM)
concentration killing, it kill more bacteria using 1 large dose
it targets gram neg. aerobic bacteria
what drug combination do you use for enteroccocal infections?
and for P. aeruginosa infection?
AG + Penicillin G / ampicillin
AG + extended spectrum penicillin/cephalosporin
what aminoglycosides are used topically?
amikacin, tobramycin, Gentamicin
what do you use for hepatic coma?
why?
Neomycin
to decrease the coliform flora, causing a decrease in the production of ammonia that causes the levels of free nitrogen to decrease in the bloodstream.
what is the least preferred aminoglycosides to prescribe?
why?
streptomycin
because it is highly nephrotoxic
what side effects can we see with aminoglycosides?
- Nephrotoxicity: Proteinuria, hypokalemia, acidosi
- Ototoxicity: causes cochlear deafness or vestibular damage (look for nausea, vertigo, dizzyness)
- Neuromuscular blockade: can cause respiratory paralysis
- Contact dermatitis: with neomycin
Neuromuscular blockade with aminoglycosides is reversible when admnistered what?
calcium and neostigmine.
what are the Tetracyclines?
Doxycycline, Chlortetracycline, Oxytetracycline, Demeclocycline, Minocycline
how do tetracyclines work?
Bind to 30S subunit, interfere with the attachment of aminoacyl tRNA to acceptor site, prevents addition of amino acids to the growing peptide
how do bacteria develop resistance to tetracyclines?
Development of efflux pumps.
what can cause tetracyclines dose to decrease?
which is the only tetracycline that has an exception to the previous question? why?
in renal dysfunction
doxycycline; eliminated by liver