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22 Cards in this Set
- Front
- Back
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How do aminoglycosides enter the cell?
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passive diffusion through porins, then coupled with a proton pump (oxygen dependent)
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Why do aminoglycosides have synergistic activity with penicillin?
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weaker cell walls allow for easier entry of the aminoglycosides
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Once in the cell, Aminoglycosides bind to...
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30s ribosomal sub-unit
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Function of Aminoglycosides
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bind to 30s ribosome: interfere with ribosomal initiation complex, misreading of mRNA, break up polysomes into nonfunctional monosomes
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Aminoglycosides lead to irreversible cell death
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fun fact
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What is the principal type of resistance to Aminoglycosides?
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transferase enzymes that inactivate the Aminoglycosides itself
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How are Aminoglycosides usually given?
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poorly absorbed in GI, so give IntraMuscular
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With Aminoglycosides, what is better. 1 big dose or multiple smaller doses?
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larger single dose is better due to post-antibiotic effect, last several hours after drug is no longer present. also less toxic
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Aminoglycosides would be least helpful to an infection in which part of the body?
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CNS or eye
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2 major toxicities of Aminoglycosides
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ototoxicity and nephrotoxicity
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Due to nephrotoxicity, Aminoglycosides should not be taken with which type of drug?
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loop diuretics or other nephrotoxic antibiotics
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Which Aminoglycosides are the most ototoxic?
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neomycin, kanamycin, amikacin
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Which Aminoglycosides are the most vestibulotoxic?
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streptomycin, gentamicin
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Which Aminoglycosides are the most nephrotoxic?
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neomycin, tobramycin, gentamicin
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Streptomycin is second line treatment for which disease?
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TB (mycobacteria)
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What is the major toxicitiy for aminoglycosides at very high doses?
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muscular blockade (myasthenia gravis, paralysis, respiratory paralysis). give calcium gluconate + neostigmine immediately
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#1 Streptomycin adverse effect
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irreversible vestibular dysfunction (vertigo, balance loss). don't give in pregnancy, baby will be deaf
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Why do Aminoglycosides have no function against anaerobes?
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to get inside the cell, they require an oxygen dependent proton pump
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Streptococci and enterococci are typically resistant to which drug?
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gentamicin. an enterococcal enzyme modifies it (also amikacin, netilmicin, tobramycin). give streptomycin instead
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For Kanamycin resistant TB, what similar drug can be given?
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Amikacin is a synthetic derivative of kanamycin specifically made to have less resistance
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Why is neomycin given before elective bowel surgery?
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reduce amount of aerobic bacteria (that shouldn't be there) in the gut, while leaving the anaerobic gut bacteria
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Main disease that uses spectinomycin?
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drug-resistant gonorrhea
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