Tobramycin

Aminoglycoside Antibiotic

Generic Name

Tobramycin

Drug Class

Aminoglycoside antibiotic

Indications

Severe Gram-negative bacterial infections
Pseudomonas infections, especially in cystic fibrosis
Septicemia
Respiratory tract infections
Skin and soft tissue infections
Bone and joint infections

Dosage

Adults: 3–6 mg/kg/day IV/IM in 1–3 divided doses
Children: 3–6 mg/kg/day IV/IM in 1–3 divided doses

Note: Monitor renal function and serum drug levels. Dose adjustment is needed in renal impairment.

Route of Administration

Intravenous (IV), Intramuscular (IM), inhalation (for cystic fibrosis), ophthalmic (drops/ointment)

Mechanism of Action

Tobramycin binds irreversibly to the 30S ribosomal subunit, inhibiting bacterial protein synthesis, causing misreading of mRNA and bacterial cell death. It is bactericidal and concentration-dependent.

Common Adverse Effects

Nausea, vomiting
Injection site reactions
Rash

Serious Adverse Effects

Ototoxicity (hearing loss, vestibular toxicity)
Nephrotoxicity (acute tubular necrosis)
Neuromuscular blockade (rare)
Anaphylaxis

Contraindications

Hypersensitivity to tobramycin or other aminoglycosides
Pre-existing auditory or vestibular damage

Precautions

Monitor renal function and serum drug levels regularly
Avoid concurrent nephrotoxic or ototoxic drugs
Use with caution in elderly and patients with renal impairment

Drug Interactions

Loop diuretics (e.g., furosemide) – increased risk of ototoxicity
Amphotericin B – increased nephrotoxicity
Other aminoglycosides – additive toxicity

Pregnancy & Lactation

Use only if clearly needed; risk of fetal/neonatal ototoxicity. Avoid in breastfeeding if possible.

Patient Counseling

Report hearing changes, vertigo, or ringing in ears immediately
Report decreased urine output or swelling
Do not skip or double doses
Follow all monitoring schedules for blood levels and renal function