Maximum Recommended Dose of Amikacin
The maximum recommended dose of amikacin is 15 mg/kg/day (not to exceed 1.0 g/day) for adults under 60 years of age, administered intramuscularly or intravenously. 1, 2
Standard Adult Dosing
- For adults under 60 years: 15 mg/kg/day is the maximum, with an absolute ceiling of 1.0 gram per day regardless of weight 1, 3
- The dose can be given as a single daily injection or divided into 2-3 equal doses (7.5 mg/kg every 12 hours or 5 mg/kg every 8 hours) 2
- For adults over 59 years: The maximum dose must be reduced to 10 mg/kg/day (750 mg/day maximum) due to increased risk of ototoxicity and nephrotoxicity 1, 3
Pediatric Dosing
- Children and older infants: 15-30 mg/kg/day (maximum 1 g/day) administered as a single daily dose 1, 3
- Newborns: A loading dose of 10 mg/kg followed by 7.5 mg/kg every 12 hours 2
Critical Dosing Principles in Renal Impairment
In patients with renal insufficiency, maintain the mg/kg dose at 12-15 mg/kg but reduce the frequency to 2-3 times per week—never reduce the individual dose amount. 1, 3 This is essential because amikacin exhibits concentration-dependent bactericidal activity, and smaller doses reduce efficacy 1. For hemodialysis patients, administer the dose after dialysis to avoid premature drug removal 3, 4.
Monitoring Requirements to Prevent Toxicity
- Target peak levels: 25-35 mg/L for daily dosing or 65-80 mg/L for three-times-weekly dosing 3, 4
- Target trough levels: Must remain <5 mg/L to prevent toxicity; levels >10 mg/L should be avoided 3, 2
- Baseline assessment must include audiogram, vestibular testing, Romberg testing, and serum creatinine 1, 3
- Monthly monitoring of renal function and auditory/vestibular symptoms is mandatory 1, 3
Major Toxicity Risks
- Nephrotoxicity occurs in 8.7% of patients overall (3.4% in those without risk factors), with higher rates in patients with baseline renal impairment, higher cumulative doses, or concurrent nephrotoxic agents 1, 3
- Ototoxicity (high-frequency hearing loss) occurs in 1.5-24% of patients, with higher rates associated with longer treatment duration, higher doses, and concurrent diuretic use 1, 3
- Repeat audiogram and vestibular testing immediately if any symptoms of eighth nerve toxicity develop 1, 3
Common Pitfalls to Avoid
Never use fixed 500 mg doses regardless of patient weight—this risks underdosing in heavier patients and treatment failure 3. Do not reduce the milligram dose in renal impairment; instead, extend the dosing interval while maintaining 12-15 mg/kg per dose 1, 3. Treatment duration should typically not exceed 7-10 days; if therapy beyond 10 days is necessary, reassess the indication and intensify monitoring of drug levels and toxicity 2.
Absolute Contraindication
Amikacin is absolutely contraindicated in pregnancy due to risk of fetal nephrotoxicity and congenital hearing loss 1, 3, 4.