Guidelines
General Information

General Information

Aminoglycosides

Aminoglycosides (AG) include gentamicin, tobramycin, amikacin and streptomycin

  • Conventional dosing of AG: weight-based dose administered three times a day, or less frequently in decreased renal function
  • Extended-interval dosing of AG (also called “once daily dosing”): a larger weight-based dose (approximately triple conventional dosing) administered once a day, or less frequently in decreased renal function
  • Synergistic dosing: for gram-positive infections

Aminoglycoside Activity

AG exert bactericidal activity against gram-negative bacteria

AG exhibit concentration-dependent killing: higher serum concentrations result in higher rates and extent of bacterial killing

AG demonstrate a post-antibiotic effect: suppression of bacterial growth is continued even after serum concentrations have decreased below the minimum inhibitory concentration (MIC)

AG are nephrotoxic, ototoxic and can produce neuromuscular blockade (in patients with myasthenia gravis, the use of AG is contraindicated)

  • Combination of gentamicin with a cell-wall active agent (i.e. beta-lactam) results in a synergistic effect on certain gram-positive bacteria such as Enterococci and Streptococci in the treatment of endocarditis
  • Amikacin is generally reserved for infections due to organisms with documented resistance to gentamicin and tobramycin; refer to amikacin section for dosing and monitoring information
  • Streptomycin is used infrequently to treat drug resistant tuberculosis and nontuberculous mycobacterial infections; its dosage and monitoring are not included in these guidelines