antibioticsbooks

102 PART 2 Antibacterial Drugs
Spectrum: gentamicin/tobramycin/amikacin
Good: Gram-negatives (E. coli, Klebsiella, Pseudomonas,
Acinetobacter, most others)
Moderate: in combination with a beta-lactam or
glycopeptide: staphylococci (including MRSA),
viridans streptococci, enterococci
Poor: atypicals, anaerobes, Gram-positive organisms
(as monotherapy)
Adverse Effects
Nephrotoxicity: Oliguric acute renal failure, preceded
by a rising serum creatinine, is a doserelated
adverse effect of aminoglycosides. Risk
can be reduced by correct dosing (including
the use of extended-interval dosing), as well as
avoidance of co-administration of other nephrotoxins
(cyclosporin, cisplatin, foscarnet, etc.).
Ototoxicity: Aminoglycosides cause dose-related
cochlear and vestibular toxicity. For patients
anticipated to receive long-term (. 2 weeks)
aminoglycosides, baseline and follow-up audiology
are necessary. It is important to monitor
patients closely for any hearing loss or balance
problems, because these are not reversible and
can significantly affect quality of life.
Neurologic: Neuromuscular blockade can occur
when aminoglycosides are given, particularly
in high doses in patients who are receiving
therapeutic paralysis.
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Important Facts
• Once-daily or extended-interval aminoglycoside
dosing leverages the concentrationdependent
killing of the drugs to create an