Gentamicin Dosing for UTI in a 24.4-pound Patient
The recommended dose of gentamicin for a child weighing 24.4 pounds (11.1 kg) with a urinary tract infection is 3 mg/kg/day administered in three equally divided doses every 8 hours, which equals approximately 11 mg per dose given three times daily. 1
Dosage Calculation
- For pediatric patients with UTI, gentamicin should be dosed at 3 mg/kg/day divided into three equal doses 2, 1
- Weight conversion: 24.4 pounds = 11.1 kg
- Total daily dose: 3 mg/kg × 11.1 kg = 33.3 mg/day
- Individual dose: 33.3 mg ÷ 3 = 11.1 mg every 8 hours 1
Administration Considerations
- Gentamicin can be administered either intramuscularly (IM) or intravenously (IV) 1
- For UTIs, the intramuscular route is often preferred in outpatient settings due to ease of administration 3
- Treatment duration for UTIs typically ranges from 7-10 days 1
- Monitoring of renal function is recommended, especially if treatment extends beyond 10 days 1
Monitoring Recommendations
- For optimal therapeutic effect and safety, both peak and trough serum concentrations should be measured when feasible 1
- Target peak concentration (30-60 minutes after administration): 4-6 mcg/mL 1
- Target trough concentration (just before next dose): <2 mcg/mL 1
- Prolonged levels above 12 mcg/mL should be avoided to prevent toxicity 1
Special Considerations
- Gentamicin's effectiveness in urine may be affected by urinary pH and osmolality, potentially requiring higher concentrations to achieve antibacterial effect 4
- Single daily dosing regimens have shown efficacy in UTI treatment in some studies but are not recommended for pediatric patients 5, 6
- If the patient has impaired renal function, dosage adjustment would be necessary 2
- The efficacy of gentamicin may be affected by the presence of urinary tract abnormalities 6
Potential Adverse Effects
- Nephrotoxicity and ototoxicity are the most significant potential adverse effects 1
- Risk increases with prolonged therapy (>10 days), higher doses, and pre-existing renal impairment 1
- Careful monitoring of renal function is essential, particularly with extended treatment courses 1
Remember that gentamicin should be used judiciously due to potential toxicity concerns, and the duration of treatment should be limited to the shortest effective period, typically 7-10 days for UTIs 1.