Gentamicin

C difficile risk
Low
Oral Bioavailability
N/A
Cost
$

Dosing

Consult pharmacy for dosing recommendations

Once Daily Dosing 5-7mg/kg IV q24h

Multiple Daily Dosing 1.5-2mg/kg IV q8h

N.B. Use Dosing Weight (aka. Adjusted Body Weight) for obese patients

General Information

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

Empiric therapy for pyelonephritis.

Used synergistically in enterococcal endocarditis.

Monitor creatinine at least 3 times/week. Discontinue if any signs of ototoxicity.

Once daily dosing: Target trough <1mcg/mL

Multiple daily dosing: Peak monitoring poorly supported by literature, but target peak 4-10mcg/mL; trough 1-2mcg/mL only if using >4 days

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

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

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.

Antimicrobial class: Aminoglycoside

Pregnancy category: D

Average serum half life: 2 hours

Biliary penetration: Moderate

CSF penetration: Poor

Lung penetration: Therapeutic

Urine penetration: Therapeutic