Tobramycin

C. diff Risk

Low

Oral Bioavailability

NA

Approximate Cost

$12/day

Dosing

4-7 mg/kg/dose IV q24h
Maximum: 500 mg/24h prior to levels

5 mg/kg/dose IV q24h
Maximum: 500 mg/24h prior to levels

EXTENDED INTERVAL INITIAL DOSING. Dosage adjustments are made based on serum concentrations, clinical response and renal function (see "Drug Monitoring").Post natal age less than or equal to 7 daysPost natal age 8 to 28 daysPost natal age greater than or equal to 29 days5 mg/kg/dose IV q48h4 mg/kg/dose IV q36h4 mg/kg/dose IV q24h

EXTENDED INTERVAL INITIAL DOSING. Dosage adjustments are made based on serum concentrations, clinical response and renal function (see "Drug Monitoring").Post natal age less than or equal to 7 daysPost natal age greater than or equal to 8 days4.5 mg/kg/dose IV q36h4 mg/kg/dose IV q24h

EXTENDED INTERVAL INITIAL DOSING. Dosage adjustments are made based on serum concentrations, clinical response and renal function (see "Drug Monitoring").4 mg/kg/dose IV q24h

Renally cleared, requires dosage adjustment with changes in renal function. Consult a pharmacist for renal dosing.

General Information

Common Usage

Pseudomonal and other gram negative infections, inhaled form used in cystic fibrosis

Adverse Effects

  • Nephrotoxicity (non-oliguric)- less common with once daily dosing; greater toxicity with longer duration and supratherapeutic trough levels; avoid concomitant nephrotoxins

  • Vestibulocochlear toxicity (irreversible)- suggest audiology testing if prolonged use

  • Can exacerbate neuromuscular blockade- e.g. contraindicated in patients with myasthenia gravis.

Major Interactions

  •  Enhanced nephrotoxic effect with concomitant use of other nephrotoxins

  •  Enhanced ototoxicity with loop diuretics (e.g. furosemide).

  •  Non-depolarizing muscle relaxants may be potentiated.

Pharmacology

Antimicrobial class: Aminoglycoside

Average serum half life: Neonates: ≤1200 g: 11 hours, >1,200 g: 2 to 9 hours.
Infants: 4 ± 1 hour.
Children: 2 ± 1 hour.
Adolescents: 1.5 ± 1 hour
Adults: IV: 1-2 hours; directly dependent upon glomerular filtration rate
Adults with impaired renal function: 5- 70 hours

Route of Elimination: With normal renal function, 93% of dose excreted in urine within 24 hours