Antimicrobials
Gentamicin

Gentamicin

Low
N/A

Dosing

General Information

  • Urinary tract infections, including urosepsis
  • EMPIRIC therapy of severely ill patients with suspected Gram-negative infections (including Pseudomonas)
  • Synergy for some Gram-positive endocarditis infections

Monitor creatinine at baseline and every 2 to 3 days.

Monitor for vestibulotoxicity/ototoxicity, discontinue if any signs.

Extended interval dosing: Target trough within 30 minutes before dose of <1 mg/L

Conventional dosing: Peak monitoring poorly supported by literature, but target peak 6-10 mg/L for most infections; trough < 2 mg/L only if using >4 days

NB: Trough level is 0-30min before a dose (usually pre-3rd or 4th dose), and peak is 30-60min after dose infused (usually post-3rd or 4th dose).

In critically ill patients, check peak level after the 1st dose as volume of distribution and renal function may change rapidly.

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

  • Perform baseline and ongoing weekly otovestibular toxicity assessment. Formal audiology assessment required if symptoms develop.
  • Inform patient of risk of ototoxicity and to report any symptoms.

Antimicrobial class: Aminoglycoside

Pregnancy category: D

Average serum half life: 2 hours

Urine penetration: Therapeutic

Lung penetration: Therapeutic; do not use as monotherapy for lung infections

CSF penetration: Poor

Biliary penetration: Moderate