Aminoglycosides Flashcards
What is a powerful group of antimicrobials that treat gram-negative, aerobic bacterial infections?
Aminoglycosides
What are examples of aminoglycosides?
Gentamicin Amikacin Neomycin Kanamycin Tobramycin Apramycin
What are two of the most commonly used Aminoglycosides?
Gentamicin
Amikacin
What is the mechanism of action of Aminoglycosides?
Action on the bacterium’s ribosomal production of essential proteins
Are Aminoglycosides bactericidal or bacteriostatic?
Bactericidal
What must happen for aminoglycosides to exert their effects?
They must be actively transported through the bacterial cell membrane using oxygen
Because Aminoglycosides need oxygen to transport into a cell membrane to be effective, they are only effective against what type of bacteria?
Aerobic bacteria
What is the effect that extends the drug’s killing activity for the full 24 hours between doses?
Postantibiotic effect
What must happen for a drug to produce a strong post antibiotic effect?
The drug must achieve a very high peak concentration even though it drops rapidly after the peak?
Aminoglycosides are concentration-dependent drug. What does that mean?
Aminoglycosides need to hit a critically high peak concentraiton for a short period of time.
What is bacterial resistance to aminoglycosides attributed to?
The destructive enzymes produced by the bacteria or the inability of the aminoglycoside to cross the cell wall or cell membrane
Aminoglycosides are considered what at most physiologic pH levels so they are usually administered parenterally?
Hydrophilic
What happens if Aminoglycosides are administered PO?
Absorption across the GI tract wall would be severely limited
If aminoglycosides are administered orally what happens?
They are intended to remain in the intestinal tract and not be absorbed to any significant extent
Can Aminoglycosides be absorbed intradermally?
No. Not unless there is a break in in the skin
Why should Aminoglycosides not be used in patients with decreased renal activity?
Because it can potentially cause nephrotoxicity
What is an early sign of aminoglycoside nephrotoxicity?
The presence of casts or increased proteins in the urine.
Aminoglycosides cause what other toxicity?
Ototoxicity
What does ototoxicity cause?
It affects balance
What species are highly sensitive to the side effects of aminoglycoside ototoxicity and what are the side effects?
Cats
Circling
Fall over
Display repetitive, rapid eye movements
Which type of aminoglyoside has the greatest potential for inducing nephrotoxicity in animals and people?
Neomycin
What drug causes nephrotoxicity in exotic animals, wildlife and birds?
Gentamicin
What blocks aminoglycosides from reaching the bacteria in the infection site?
Cellular debris or pus
