tobramycin sulfate: clinical use

Prescribing considerations

• Confirm that the suspected or proven pathogen and local susceptibility information support tobramycin.
• Assess renal function, hydration, age, body weight, previous aminoglycoside exposure and concurrent nephrotoxic or ototoxic treatment.
• Consider alternatives for patients with a relevant mitochondrial mutation or maternal family history of aminoglycoside-associated deafness; urgent treatment should not be delayed solely for genetic testing.
• Use particular caution in renal impairment, older people, premature or neonatal infants, extensive burns, myasthenia gravis and parkinsonism.
• Review therapy if non-susceptible organisms overgrow or renal, auditory or vestibular impairment emerges.

Contraindications and cautions

• Hypersensitivity to tobramycin, another aminoglycoside or a formulation excipient
• Intrathecal administration

Monitoring

• Baseline and serial renal function, including serum creatinine or creatinine clearance
• Tobramycin serum concentrations where feasible, especially with renal impairment, changing renal function, chronic infection or extended exposure
• Auditory and vestibular function, particularly in higher-risk patients
• Urinalysis for protein, cells and casts where clinically appropriate
• Serum calcium, magnesium and sodium; consider broader laboratory monitoring according to clinical status

Clinical pharmacology

Tobramycin is a bactericidal aminoglycoside that inhibits bacterial protein synthesis. Systemic distribution includes the inner ear and kidneys. Elimination is almost entirely by renal glomerular filtration, so impaired renal function can cause accumulation and toxicity.

Formulation and product differences

• The selected product is a clear, colourless solution for intramuscular or intravenous administration.
• It contains sodium metabisulfite, which can rarely cause severe hypersensitivity reactions or bronchospasm, particularly in susceptible people with asthma.
• It is not licensed for intrathecal, intraocular or subconjunctival injection.
• Physical mixing with other medicines should be avoided because incompatibility or loss of activity can occur.

Injection

Route: Parenteral

Strengths: 40 mg/mL