Home Drug Guide Tobramycin Sulfate

Drug Guide

Generic Name

Tobramycin Sulfate

Brand Names Nebcin, Tobramycin Sulfate In Sodium Chloride 0.9% In Plastic Container, Tobramycin Sulfate (pharmacy Bulk)

Classification

Therapeutic: Antibiotic, Aminoglycoside

Pharmacological: Inhibits bacterial protein synthesis via binding to 30S ribosomal subunit

FDA Approved Indications

Treatment of serious bacterial infections caused by susceptible Gram-negative bacteria, including Pseudomonas aeruginosa, Escherichia coli, Klebsiella species, Serratia marcescens, and Proteus mirabilis.

Mechanism of Action

Tobramycin binds to the 30S subunit of bacterial ribosomes, inhibiting protein synthesis, leading to bacterial cell death.

Dosage and Administration

Adult: Dosage varies based on infection severity; typically 1-2 mg/kg every 8-12 hours IV or IM, adjusted based on renal function.

Pediatric: Doses are calculated based on weight; usual range is 13-16 mg/kg/day divided every 8-12 hours.

Geriatric: Adjust dose based on renal function; monitor closely for toxicity.

Renal Impairment: Reduce dosage and monitor serum drug levels due to decreased clearance.

Hepatic Impairment: No specific adjustment, but monitor for toxicity.

Pharmacokinetics

Absorption: Poorly absorbed from GI tract, administered parenterally.

Distribution: Widely distributed; achieves therapeutic levels in serum, moist tissues, lungs, CSF (with meningeal inflammation).

Metabolism: Not significantly metabolized.

Excretion: Primarily excreted unchanged via kidneys.

Half Life: Approximately 2-3 hours in normal renal function.

Contraindications

Hypersensitivity to aminoglycosides.
History of vestibular or auditory dysfunction related to aminoglycoside use.

Precautions

Use with caution in pre-existing renal impairment, pregnancy, elderly, and patients receiving other ototoxic or nephrotoxic drugs. Monitor renal function and serum drug levels closely.

Adverse Reactions - Common

Nephrotoxicity (Possible with prolonged use)
Ototoxicity (auditory and vestibular) (Possible, especially with high doses or prolonged therapy)

Adverse Reactions - Serious

Neurotoxicity, including neuromuscular blockade and respiratory paralysis (Rare but serious)
Hypersensitivity reactions (Rare)

Drug-Drug Interactions

Loop diuretics (e.g., furosemide) increase ototoxicity risk.
Other nephrotoxic drugs (e.g., amphotericin B).

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor renal function (BUN, serum creatinine), hearing, and balance.

Diagnoses:

Risk for renal impairment
Risk for ototoxicity

Implementation: Administer IV or IM doses as prescribed; monitor serum drug levels to maintain therapeutic but non-toxic levels.

Evaluation: Assess for signs of toxicity; ensure infection resolution.

Patient/Family Teaching

Report ringing in ears, dizziness, or signs of kidney problems immediately.
Complete full course of therapy; do not stop early.

Special Considerations

Black Box Warnings:

Nephrotoxicity, Ototoxicity, Neuromuscular blockade.

Genetic Factors: Genetic predisposition may increase risk of ototoxicity.

Lab Test Interference: Serum creatinine and BUN levels may be affected.

Overdose Management

Signs/Symptoms: Auditory dysfunction, significant renal impairment, neuromuscular paralysis.

Treatment: Discontinue drug, provide supportive care, and consider hemodialysis for severe cases.

Storage and Handling

Storage: Store at room temperature, protected from light and moisture.

Stability: Stable until expiration date on packaging.