Parenteral Manual

Tobramycin sulphate

Disclaimer: Official controlled document is the CHEO online copy. It is the responsibility of user to ensure that any paper copy version is the same as the online version before use.

Alternate Name(s): 
Original Date: 
August 2005
Revised Date: 
June 2020
  • Aminoglycoside antibiotic for the treatment of serious infections caused by susceptible bacteria (primarily gram negative)
  • Preferred for susceptible isolates of pseudomonas
Reconstitution and Stability: 
  • Available as 40 mg/mL solution
  • Stable at room temperature
  • Vial stable 28 days refrigerated once punctured
  • Solution stable 9 days refrigerated when diluted in 0.9% NaCl

- Solutions Compatible: dextrose up to D10W, 0.9% NaCl, dextrose-saline combinations, ringer's solution, ringer's lactate

- Additive/Above Cassette Compatible: no information

- Y-site Compatible: fluconazole, heparin (0.5 - 1 unit/mL), morphine, KCl, TPN (amino acids/dextrose)

- Incompatible: azithromycin, clindamycin, heparin (greater than 1 unit/mL), indomethacin, propofol; Do not mix with beta lactam antibiotics.  Flush line well between administration of beta lactams and aminoglycoside antibiotics.                              


(For approved routes of administration by nursing personnel, refer to Policy for the Administration of Intravenous Medications.)

Usual dilution: undiluted- 40 mg/mL
IV Direct NO
IV Intermittent Infusion

Usual dilution: 10 mg/mL

- 1 mg/mL for dose less than or equal to 10 mg
Infusion time: 30 minutes

IV Continuous Infusion NO




(For neonatal dosages, refer to Neonatal IV Drug Manual.)


  • Traditional dosing:  7.5 mg/kg/day IM/IV ÷ Q 8 hours . Maximum 120 mg/dose if no previous levels
  • Single daily dosing:  7 mg/kg IM/IV once daily.  Maximum 360 mg/dose if no previous levels
  • Combination therapy for synergy in selected infections: 3 mg/kg/day divided Q8H.  Maximum 80 mg/dose before levels
  • Cystic Fibrosis Patients:  10 mg/kg/dose IV daily, no MAX

(dosage may be higher based on serum concentrations)


Dose interval adjustment in renal impairment with traditional dosing:

  • CrCl 40 - 60 mL/minute:  Administer Q 12 hours
  • CrCl 20 - 39 mL/minute:  Administer Q 24 hours
  • CrCl < 20 mL/minute:  Administer normal dose, then monitor levels

    Adjust regimen based on serum concentrations  

Potential hazards of parenteral administration: 
  • Ototoxicity (dizziness, vertigo, tinnitus, hearing loss) - associated with high peak levels following rapid IV bolus administration
  • Neurotoxicity (neuromuscular blockade)
  • Nephrotoxicity - associated with high trough levels
  • Local reactions at injection site, thrombophlebitis
  • Elevated liver enzymes
  • Hypomagnesemia
  • Hypersensitivity reactions                                       
  • Use with caution in patients with renal impairment, pre-existing auditory or vestibular impairment or neuromuscular disorders
  • Adverse effects potentiated by other ototoxic and nephrotoxic drugs
  • Apnea may result when combined with anesthetic or other neuromuscular blocking drugs
  • Maintain good hydration, baseline serum creatinine and repeat once weekly
  • An audiology consult is recommended if IV aminoglycoside therapy is expected to continue for 14 days. Repeat every 7 days if therapy continues. 

Therapeutic Drug Monitoring:

 Single Daily Dosing
- When checking level, administer next dose as scheduled.  Do not wait for levels to be reported unless otherwise advised.
- Initial level on Day 3 and repeat once weekly
          - PRE (Trough): 0 - 30 min prior to next dose               
                   -  less than 0.3 mg/L
          - POST (Peak): not recommended

 Traditional Dosing
- Initial levels on Day 3 and repeat once weekly
         - PRE: 0 - 30 min prior to next dose
                   - less than 2 mg/L
         - POST: 30 min after end of infusion
                     - 5-10 mg/L (may be higher in Cystic Fibrosis)

Combination therapy for synergy:

- Initial level on Day 3 and repeat once weekly

         - PRE: 0 - 30 minutes prior to next dose
                   - less than 0.3 mg/L
         - POST:  not recommended





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