Amikacin Dosing for a 6-Year-Old Child Weighing 9.65 kg
For this 6-year-old child weighing 9.65 kg, administer amikacin 145 mg (15 mg/kg/day) divided into two equal doses of 72.5 mg every 12 hours, or as a single daily dose of 145 mg once daily.
Standard Pediatric Dosing
- The FDA-approved dosage for children and older infants with normal renal function is 15 mg/kg/day, administered either as 7.5 mg/kg every 12 hours or 5 mg/kg every 8 hours 1
- For this 9.65 kg child, the total daily dose calculates to 144.75 mg (approximately 145 mg) 1
- The divided dosing would be either 72.5 mg every 12 hours or 48 mg every 8 hours 1
Once-Daily Dosing Alternative
- Single daily dosing of 20 mg/kg (193 mg for this child) has been studied in pediatric patients with severe gram-negative infections and may be considered 2
- This regimen achieved mean peak concentrations of 49-54 mg/L and trough concentrations of 6-8 mg/L, with all patients achieving clinical and bacteriological cure 2
- Once-daily dosing is pharmacokinetically appropriate and may offer practical advantages 3, 2
Therapeutic Monitoring Requirements
- Peak serum concentrations (measured 30-90 minutes after injection) should remain below 35 mcg/mL, and trough concentrations (just prior to next dose) should stay below 10 mcg/mL 1
- Measure both peak and trough levels intermittently during therapy to ensure adequate but not excessive concentrations 1
- The usual treatment duration is 7-10 days, though this should be limited to the shortest effective period 1
Clinical Response Expectations
- Uncomplicated infections due to amikacin-sensitive organisms should respond within 24-48 hours 1
- If no definite clinical response occurs within 3-5 days, therapy should be stopped and antibiotic susceptibility retested 1
- Treatment beyond 10 days requires re-evaluation with monitoring of amikacin serum levels, renal function, and auditory/vestibular function 1
Important Safety Considerations
- The total daily dose by all routes should not exceed 15 mg/kg/day (or 20 mg/kg if using once-daily dosing) 1, 2
- Amikacin shares the risk of ototoxicity and nephrotoxicity with other aminoglycosides 4
- Renal function should be assessed before treatment by measuring serum creatinine or calculating creatinine clearance, with periodic reassessment during therapy 1
Common Pitfalls to Avoid
- Do not use BUN alone to estimate renal function, as it is much less reliable than serum creatinine or creatinine clearance 1
- Avoid exceeding the maximum daily dose of 1.5 grams, even in heavier patients 1
- Do not continue therapy beyond 10 days without formal re-evaluation and enhanced monitoring 1
- Previous exposure to gentamicin is a major risk factor for developing ototoxicity or nephrotoxicity 4