Tobramycin

C. diff Risk

Low

Oral Bioavailability

NA

Approximate Cost

$

Dosing

Multiple Daily Dose 2mg/kg IV load, then 1.7mg/kg IV q8h

Once Daily 5-7mg/kg IV q24h IV

Consult pharmacy for dosing recommendations

General Information

Common Usage

Pseudomonal and other gram negative infections.

Inhaled form used in cystic fibrosis.

Drug Monitoring

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

For Multiple daily dosing: Target Peak 4-10 ug/mL, Trough 1-2 ug/mL.

For Once daily: Target Trough <1 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.

Adverse Effects

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

Major Interactions

Increased nephrotoxicity

  • Amphotericin B

  • Cyclosporine

  • Cisplatin

  • NSAIDS

  • Contrast dye

  • Vancomycin

Increased ototoxicity

  • Furosemide

Neuromuscular blockade agents - Respiratory paralysis.

Additional Information

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

Pharmacology

Antimicrobial class: Aminoglycoside

Pregnancy category: D

Average serum half life: 3 hours

Urine penetration: Therapeutic

Lung penetration: Therapeutic

CSF penetration: Poor

Biliary penetration: Moderate