Antimicrobials
Gentamicin

Gentamicin

Restricted

Low
N/A
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General Information

Restricted Antimicrobial: See Approved Indications of Use.

Empiric (in combination) or targeted therapy for suspected or confirmed gram negative infections.

Empiric therapy for pyelonephritis.

Used synergistically for endocarditis.

Note: Autosub to tobramycin at OSMH unless clinically indicated for restricted use.

Pharmacist will consult, adjust dose and order serum drug levels and renal function monitoring.

Monitor Serum creatinine every Monday, Wednesday and Friday while on Gentamicin. Discontinue if any signs of ototoxicity.

Extended Interval Target Levels

  • Trough level: < 1mg/L
  • Peak level: not needed

Traditional Target Levels

Target Trough Level (mg/L) Target Peak-Level (mg/L)
Serious Infections: < 1mg/L UTI including pyelonephritis: 4-6
Life threatening infections:    < 2mg/L Sepsis, pneumonia, other serious infections: 6-8
  Life-threatening infections: 8-10

Notes:

  • No aminoglycoside levels are required in prophylactic use up to 48 hours, if renal function is normal.
  • For Traditional Dosing trough level prior to 4th dose
  • For Extended Interval Dosing trough level prior to 2nd dose
  • Trough level 0-60mins prior to dose
  • Peak level 30mins after dose infused

Nephrotoxicity (non-oliguric)

  • Avoid concomitant nephrotoxins

  • Less common with once daily dosing

  • Greater toxicity with longer duration and supratherapeutic trough levels

Vestibulocochlear toxicity

  • Irreversible

  • Require audiology testing if prolonged use

Can exacerbate neuromuscular blockade

  • Contraindicated in patients with myasthenia gravis

Increased nephrotoxicity

  • Amphotericin
  • Vancomycin
  • Cyclosporin
  • NSAIDs
  • Contrast

Increased ototoxicity

  • Loop diuretics (e.g. furosemide)

Non-depolarizing muscle relaxants may be potentiated.

Formal audiology assessment if planning to use aminoglycoside for >7d or if symptoms develop.

Inform patient of risk of ototoxicity and to report any symptoms.

With the exception of urinary tract infections, aminoglycosides are generally used in combination with other agents that have gram-negative activity, regardless of dosing method

  • Because of poor activity and/or penetration into lungs, abscesses, and the central nervous system, intravenous aminoglycosides should not be relied upon as monotherapy in infections that involve these sites
  • Limitations in the distributions of aminoglycosides restrict their use for infections at certain anatomical sites, as poor penetration is achieved in the CSF, biliary tree and bronchial secretions

Antimicrobial class: Aminoglycoside

Pregnancy category: D

Average serum half life: 2 hours

Biliary penetration: Moderate

CSF penetration: Poor

Lung penetration: Therapeutic

Urine penetration: Therapeutic