Tobramycin

How it works

It binds the bacterial 30S ribosomal subunit, inhibiting protein synthesis and producing a concentration-dependent bactericidal effect, principally against aerobic Gram-negative organisms.

Prescribing in practice

• Nephrotoxicity and ototoxicity (both auditory and vestibular, and potentially irreversible) are the key hazards, so therapeutic drug monitoring and renal monitoring are essential.
• Avoid concurrent use with other nephrotoxic or ototoxic drugs wherever possible, and adjust dosing in renal impairment.
• Use with caution in myasthenia gravis and other neuromuscular disorders, as aminoglycosides may impair neuromuscular transmission.

Monitoring

Monitor serum drug concentrations to guide dosing, together with renal function; assess auditory and vestibular function during prolonged courses and review hydration status. Limit the duration of treatment in keeping with antimicrobial stewardship.

Counselling the patient

• Report any hearing loss, ringing in the ears, dizziness or unsteadiness without delay.
• Report a marked reduction in urine output or new swelling.
• Attend for the blood tests arranged to check drug levels and kidney function.

Evidence & guidelines

An established aminoglycoside in UK practice; dosing and monitoring should follow local antimicrobial guidance.