Antimicrobials

Tobramycin

C. diff Risk

Low

Oral Bioavailability

NA

Approximate Cost

$12/day

Dosing

Conventional Dosing
2mg/kg IV load then 1.7mg/kg IV q8h

High Dose Extended Interval (HDEI)
5-7mg/kg IV q24h IV

General information

Pseudomonal and other gram negative infections.

Inhaled form used in cystic fibrosis.

Consult pharmacist for level interpretation and dosing.

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

For HDEI
Target Trough <1 ug/mL

For Conventional Dosing
Trough 1-2 ug/mL; Target Peak 4-10 ug/mL

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 HDEI

  •  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 B

  •  Cyclosporine

  •  Cisplatin

  •  NSAIDS

  •  Contrast dye

  •  Vancomycin

Increased ototoxicity

  •  Furosemide

Increased risk of respiratory paralysis

  •  Neuromuscular blockade agents.

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

Inform patient of risk of ototoxicity and to report any symptoms (oscillopsia, imbalance, hearing loss, tinnitus).

Antimicrobial class: Aminoglycoside

Pregnancy category: D

Average serum half life: 3.0

Biliary penetration: Moderate

CSF penetration: Poor

Lung penetration: Therapeutic

Urine penetration: Therapeutic