C. diff Risk


Oral Bioavailability


Approximate Cost



Traditional Dosing
1.5-2mg/kg IV q8h

Extended Interval Dosing
5-7mg/kg IV q24h

Use Adjusted Body Weight for obese patients

Recommend dosing per pharmacy

Infections caused by organisms with suspected/documented resistance to gentamicin.

General Information

Common Usage

Pseudomonal and other Gram negative infections.

Inhaled form used in cystic fibrosis

Drug Monitoring

Monitor creatinine at least 2 times/week. Discontinue if any signs of nephro- or ototoxicity.

For traditional dosing: Target Peak 8-10 ug/mL, Trough <1 ug/mL.

For extended interval dosing: Target Trough <1 ug/mL

Note: 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.

Baseline and periodic hearing and vestibular function (questioning audiologic testingwith prolonged therapy)

Adverse Effects

  • Nephrotoxicity

  • Auditory toxicity

  • Vestibular toxicity

  • Neuromuscular blockade

Major Interactions

Increased nephrotoxicity with: 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 to report any symptoms


Antimicrobial class: Aminoglycoside

Pregnancy category: D

Average serum half life: 3 hours

Biliary penetration: Moderate

CSF penetration: Poor

Lung penetration: Therapeutic

Urine penetration: Therapeutic