What is the recommended dosage of Amikacin (an aminoglycoside antibiotic) for pediatric patients?

Amikacin Pediatric Dosing

For infants and children with normal renal function, administer amikacin 15-22.5 mg/kg/day divided every 8 hours (5-7.5 mg/kg every 8 hours), with neonatal dosing stratified by weight and postnatal age. 1, 2

Standard Pediatric Dosing (Infants and Children)

• Administer 15-22.5 mg/kg/day divided every 8 hours for infants and children with normal renal function 1, 2
• This translates to 5-7.5 mg/kg every 8 hours as the practical dosing interval 1
• Maximum daily dose should not exceed 1.5 grams/day in heavier weight classes 3

Alternative Once-Daily Dosing

• For specific high-risk populations (cystic fibrosis, febrile neutropenia), consider 30 mg/kg/day divided every 8 hours when serum levels document the need 1, 2
• Once-daily dosing of 15 mg/kg every 24 hours has been studied and may be appropriate, though a loading dose of 20 mg/kg is recommended to achieve therapeutic peak concentrations of 30-40 mg/L 4
• Once-daily regimens of 15-20 mg/kg have shown efficacy in pediatric patients, particularly for urinary tract infections 5, 6

Neonatal Dosing (Weight and Age-Based)

Neonatal dosing requires careful stratification by both weight and postnatal age 1, 2:

For neonates 0-7 days postnatal age:

• <1200 g: 7.5 mg/kg every 18-24 hours 1, 2
• 1200-2000 g: 7.5 mg/kg every 12 hours 1
• >2000 g: 7.5-10 mg/kg every 12 hours 1

For neonates >7 days postnatal age:

• <1200 g: 7.5-10 mg/kg every 8-12 hours 1, 2
• 1200-2000 g: 7.5-10 mg/kg every 8-12 hours 1
• >2000 g: 10 mg/kg every 8 hours 1

Alternative neonatal approach: A loading dose of 10 mg/kg initially, followed by 7.5 mg/kg every 12 hours 3

Therapeutic Drug Monitoring

• Measure peak levels 30-90 minutes after infusion with target concentrations of 30-40 mg/L for once-daily dosing or 25-35 mg/L for divided dosing 2, 7
• Measure trough levels just prior to the next dose with target <5-10 mg/L to prevent toxicity 2, 7, 3
• Peak concentrations above 35 mcg/mL and trough concentrations above 10 mcg/mL should be avoided 3
• Initial serum monitoring is essential in pediatric populations due to wide interpatient variability in pharmacokinetic parameters 4

Critical Pitfalls to Avoid

• Never use fixed 500 mg doses in pediatrics—this ignores weight entirely and risks treatment failure 2
• Do not exceed 15 mg/kg/day total dose by all routes unless specifically indicated for cystic fibrosis or febrile neutropenia with documented serum level needs 1, 3
• Limit treatment duration to 7-10 days whenever feasible; if treatment beyond 10 days is required, monitor amikacin serum levels and renal, auditory, and vestibular functions closely 3
• Adjust dosing in renal impairment by either prolonging intervals or reducing doses based on creatinine clearance 3

Special Clinical Situations

• Cystic fibrosis patients: May require 30 mg/kg/day divided every 8 hours due to altered pharmacokinetics and higher clearance rates 1, 2, 8
• Febrile neutropenic patients: Similarly may require 30 mg/kg/day divided every 8 hours based on serum level documentation 1, 2
• Urinary tract infections: Once-daily intramuscular amikacin at 15 mg/kg/day has shown 96% efficacy for ESBL-producing E. coli UTIs in outpatient settings 5

Safety Considerations

• No nephrotoxicity was observed in multiple pediatric studies using once-daily dosing regimens 4, 5, 9
• Ototoxicity risk is low but requires monitoring, particularly with prolonged therapy; mild high-frequency hearing deficits (predominantly unilateral and reversible) occurred in 10-25% of patients in some studies 9
• Monitor serum creatinine at baseline and during therapy to assess renal function 3