- See:
aminoglycosides
- Discussion:
- adult dose w/ normal renal F(x) & serious infection: 1mg/kg q8hr;
- peds: 7.5 mb/kg/day q8hr (Levels: trough <2; peak: 4-8 hr)
- for life threatening infection may use 1.66mg/kg q8hr (reduce dose as soon as possible);
- commonly added to cement for treatment of orthopaedic infections; (see
addition of antibiotics to cement)
- gent and tobra may have similar antibacterial spectra; however, in vitro a given concetration of tobra is may be twice as effective as gent against
pseudomonas
- tobra is more active than gent against pseudomonas, including gent-resistant strains, and is usually indicated over gent for pseudomonas infections,
in combination with an antipseudomonal penicillin (AMA, 1983).
- diffusion from blood into CSF minimal even w/Inflammation;
- Cautions:
- in patients with impaired renal f(x);
- give initial loading dose of 1mg/kg;
- additional doses should be adjusted based on the creatinine clearance;
- must measure serum levels; use with caution in patients w/ renal failure;
- avoid other nephrotoxic, ototoxic drugs; Monitor CN VIII F(x);
- note that advanced age and dehydration increase the risk of toxicity;
- dosing regimens for patients with renal insufficiency: dose for 70kg adult: gm / dosing interval (hr):
- >80: 0.10-.14/8; CrCl:50-79:.10-.14/8-12hr;
- CrCl:30-49:0.10-0.14/12-18hr; CrCl:10-29:: 0.10-0.14/24-36hr;
- 84-93% of drug will be excreted in to urine (w/ nl RF(x));
- supplement dose after dialysis:
- hemo: 1-2 mg/kg
- CAPD: 3-4 mg/Lit of dialysis
- neuromuscular blockade; hallucinations;
- interactions:
- will interact with cephalothin (nephrotoxicity), Cis platin (nephrotoxicity, ototoxicity)
- neuromuscular blocking agents (apnea or respiratory paralysis), loop diuretics (ototoxicity), penicilln in RF (decrease aminoglycocans effectiveness)
vancomycin (nephrotoxicity), oral anticoagulants (increase PT);
- References for Tobramycin:
The absence of nephrotoxicity and differential nephrotoxicity between tobramycin and gentamicin.
Wound and serum levels of tobramycin with the prophylactic use of tobramycin-impregnated polymethylmethacrylate beads in compound fractures.
Aminoglycoside pharmacokinetics: dosage requirements and nephrotoxicity in trauma patients.
Comparative cost effectiveness of gentamicin and tobramycin.
Systematically individualizing tobramycin dosage regimens.
