antibioticsbooks

Aminoglycosides
9
Agents: gentamicin, tobramycin, amikacin,
streptomycin, spectinomycin
The aminoglycosides as a class dispel the notion
that antibiotics are largely nontoxic. These drugs
have a narrow therapeutic window, and improper
dosing carries the risk of inflicting significant
toxicity (primarily nephro- and ototoxicity) on your
patients. Because of this, there has been a reduction
in their use as primary therapy for most infections.
That being said, they retain good activity against
many problem pathogens (such as Pseudomonas
and Acinetobacter) that have developed resistance
to the more benign drug classes. They are also
excellent at synergizing with the beta-lactams
and glycopeptides to improve the efficiency of
bacterial killing. Gentamicin and tobramycin are
the most widely used drugs, amikacin is generally
reserved for pathogens resistant to the first two,
and streptomycin has limited uses (Enterococcus,
tuberculosis, and plague).
Mechanism of Action
Aminoglycosides bind to the bacterial ribosome (the
30S subunit, if you must know), causing misreading
of the genetic code, leading to incorrect protein formation
and interruption of protein synthesis.