Antimicrobials
Gentamicin

Gentamicin

Low
N/A
$22.50/day

Dosing

General Information

Monotherapy of gram positive or anaerobic infections

  • Empiric (in combination) or targeted therapy for suspected or confirmed gram negative infections.
  • Empiric therapy for pyelonephritis.
  • Used synergistically in enterococcal endocarditis.
  • Serum creatinine whenever initiating any aminoglycoside.
  • Creatinine and trough level should be monitored AT LEAST twice weekly; more often if unstable renal function or addition of nephrotoxic medications.

Order appropriate trough level for dosage regimen being used

Once Daily/Extended Interval Dosing

  • Order 6 hour pre-dose level
  • Target level: less than 1 mg/L

Multiple Daily Dosing

  • Order gentamicin trough level (0-60 min before a dose)
  • Desired result: less than 2 mg/L

Gentamicin Peaks

  • Are not used in once daily/extended interval regimens
  • For multiple daily dosing regimens, peaks not commonly measured but if required are collected 30-60 min after dose infused

Nephrotoxicity

  • Avoid concomitant nephrotoxins
  • Less common with once daily dosing
  • Greater toxicity with longer duration and supratherapeutic trough levels

KEEP DURATION TO MINIMUM POSSIBLE FOR INDICATION BEING TREATED

Vestibulocochlear toxicity

  • Irreversible
  • recommend audiology testing if prolonged use

Other

  • Can exacerbate neuromuscular blockade
  • Contraindicated in patients with myasthenia gravis

Increased nephrotoxicity

  • Amphotericin
  • Vancomycin
  • Cyclosporin
  • NSAIDs
  • Contrast dye

Increased ototoxicity

  • Loop diuretics (e.g. furosemide)

Non-depolarizing muscle relaxants may be potentiated

IV Administration: Dilute in 100 mL D5W or NS and administer over 30-60 min. (60 min for extended interval dosing)

A typical Hemodialysis may remove up to 50% of gentamicin. As such pre-dialysis levels of 1.5 to 3 mg/L are considered acceptable in this population.

Antimicrobial class: Aminoglycoside

Pregnancy category: D

Average serum half life: 2 hours

Biliary penetration: Moderate

CSF penetration: Poor

Lung penetration: Therapeutic

Urine penetration: Therapeutic