Antimicrobials
Tobramycin

Tobramycin

Low
N/A

Dosing

General Information

Administration

  • Intermittent infusion over 20-60 minutes
  • Higher doses generally administered over 60 minutes

Preparation

  • Solution for injection diluted in 50-100mL NS or D5W

Diluent

  • NS or D5W
  • Pseudomonal and other gram negative infections.
  • Inhaled form used in cystic fibrosis.

Tier 2 Protected Antimicrobial

  • Broad spectrum, but 1st line for common infections, comes with a high risk of poor stewardship if initial workup and follow-up are not in place

Strategies Used:

  1. Appropriate workup initially
  2. Pharmacists audit/de-escalate
  3. Set EBM Duration

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

Hartford Nomogram

  • Obtain Level 6-14 hours after the start of the 1st infusion and plot on nomogram
  • Nomogram for 7mg/kg, if using different dose divide 7 by mg/kg used times level for appropriate level on nomogram
  • If level falls on the line: choose longer regimen
  • If unable to be obtain on nomogram: use traditional dosing

Traditional Dosing

  • 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, consider checking peak level after the 1st dose as volume of distribution and renal function may change rapidly.
  • Monitor creatinine at least 3 times/week. Discontinue if any signs of ototoxicity.
  • Inform patient of risk of ototoxicity and to report any symptoms.

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.

Common Side Effects:

  • Headache
  • Confusion
  • Skin rash
  • N/V/D
  • Increased liver enzymes
  • Decreased serum electrolytes: calcium, magnesium, potassium, sodium

Increased nephrotoxicity

  • Amphotericin B
  • Cyclosporine
  • Cisplatin
  • NSAIDS
  • Contrast dye
  • Vancomycin
  • Foscarnet
  • Mannitol

Increased ototoxicity

  • Furosemide

Neuromuscular blockade agents - Respiratory paralysis.

Antimicrobial class: Aminoglycoside

Pregnancy category: D

Average serum half life: 3 hours

Biliary penetration: Moderate

Bone penetration: Poor

CSF penetration: Poor

Lung penetration: Therapeutic

Urine penetration: Therapeutic