What is the administration rate for 480mg of Gentamicin (gentamicin) intravenous (IV)?

Administration Rate for Gentamicin 480mg/100mL IV

For a 480mg dose of gentamicin in 100mL, the administration rate should be infused over 30-60 minutes to minimize toxicity.

Dosing Considerations for Gentamicin

Gentamicin is an aminoglycoside antibiotic commonly used for serious gram-negative infections, including in combination therapy for infective endocarditis. The administration rate is critical for both efficacy and safety.

Standard Administration Guidelines

• Infusion time: 30-60 minutes is the standard infusion time for gentamicin
• Concentration: 480mg in 100mL is an appropriate dilution
• Rate calculation: For a 30-minute infusion, administer at 200mL/hour

Dosing Based on Clinical Context

According to guidelines, gentamicin dosing varies by indication:

• For infective endocarditis: 3-6 mg/kg/day IV divided every 8 hours for pediatric patients; 3-5 mg/kg/day for adults 1
• For prosthetic valve endocarditis: 3 mg/kg per 24 hours IV/IM in 2 or 3 equally divided doses for 2 weeks 1

Monitoring Parameters

When administering gentamicin, monitoring is essential:

• Peak levels: Target 3-4 μg/mL (when using traditional dosing)
• Trough levels: Target <1 μg/mL before next dose to minimize toxicity
• Timing of levels: Draw peak 30 minutes after completion of infusion

Special Considerations

Patient-Specific Factors

Several factors affect gentamicin pharmacokinetics:

• Volume of distribution: Critically ill patients often have an increased Vd (0.41-0.43 L/kg vs 0.25 L/kg in healthy individuals) 2, 3
• Gender differences: Women may have higher Vd/kg and require higher mg/kg dosing 2
• Renal function: Clearance decreases with age, organ failure, and reduced creatinine clearance 2

Common Pitfalls to Avoid

1. Underdosing: Initial doses are often too low in critically ill patients
2. Inadequate monitoring: Failure to check levels can lead to toxicity
3. Prolonged therapy: Limit gentamicin to short courses (3-5 days) when possible 4
4. Rapid infusion: Administering too quickly can increase risk of toxicity

Administration Protocol

1. Dilute 480mg gentamicin in 100mL compatible solution
2. Program infusion pump for 30-60 minutes (200mL/hr for 30 min or 100mL/hr for 60 min)
3. Monitor for adverse effects during infusion
4. For multi-day therapy, check trough levels before next dose to ensure <1 μg/mL

Remember that gentamicin has a narrow therapeutic window, making proper administration rate crucial for balancing efficacy and minimizing nephrotoxicity and ototoxicity.