Posology
The dose must be adjusted individually, based on body weight and renal function, and the serum concentration must be monitored regularly.
Amikacin can be given intramuscularly or intravenously in the same dosage. For intravenous administration, the dose is added to the appropriate infusion solution (see section 6.6) and administered as an infusion over 30-60 minutes.
Adults and children over 12 years of age:
The recommended intramuscular or intravenous dose for adults and adolescents with normal renal function (creatinine clearance ≥50 mg/min) is 15 mg/kg/day given either as a single daily dose or as several equal doses (e.g. 7.5 mg/kg all 12 hours, or 5 mg/kg every 8 hours).
The total daily dose should not exceed 1.5 g. For endocarditis and febrile neutropenic patients, dosing should be done twice a day, as there is insufficient data for once-daily dosing.
Children from 4 weeks to 12 years of age:
The recommended intramuscular or intravenous (slow intravenous infusion) dosage for children with normal renal function is 15-20 mg/kg/day, given either as a single daily dose of 15-20 mg/kg or divided into two doses of 7.5 mg/kg every 12 hours.
For endocarditis and febrile neutropenic patients, dosing should be done twice a day, as there is insufficient data for once-daily dosing.
Neonates:
An initial dose of 10 mg/kg, then 7.5 mg/kg every 12 hours (see sections 4.4 and 5.2).
Preterm infants:
The recommended dose for preterm infants is 7.5 mg/kg every 12 hours (see sections 4.4 and 5.2).
Dosage in elderly patients (≥ 65 years):
Renal function should be taken into account in elderly patients (see section 5.2).
Endocarditis:
In endocarditis caused by Enterococcus faecalis or alpha streptococcus, Amikacin should be combined with ampicillin and benzylpenicillin, respectively.
In case of endocarditis caused by staphylococci, Amikacin should be combined with an isoxazolyl penicillin.
Neutropenic patients:
When treating neutropenic patients, Amikacin should be combined with piperacillin and tazobactam.
In the case of serious infections of unknown etiology, Amikacin should be combined with a beta-lactam antibiotic while waiting for a culture and resistance report.
Systemic infections caused by Pseudomonas
The adult dose may be increased to 500 mg every eight hours but should neither exceed 1.5 g/day nor be administered for a period longer than 10 days. A maximum total adult dose of 1.5 g should not be exceeded.
In case of systemic infection caused by Pseudomonas aeruginosa, Amikacin can be combined with a beta-lactam antibiotic effective against Pseudomonas aeruginosa.
When treating infections caused by both aerobic and anaerobic bacteria, Amikacin should be combined with a preparation active against anaerobic bacteria.
Urinary tract infections (other than pseudomonal infections):
7.5 mg/kg/day in two equally divided doses (equivalent to 250 mg twice daily in adults). As the activity of amikacin is enhanced by increasing the pH, a urinary alkalizing agent may be administered concurrently.
Impaired renal function
It is especially important in the case of impaired renal function that the serum concentration of amikacin is monitored regularly.
Since amikacin is mainly eliminated by the renal by glomerular filtration, the rate of elimination depends on the patient's renal function and the recommended daily dose should therefore be adapted to renal function. If renal function is impaired and the dose is not reduced and/or the dosing intervals are not extended, abnormally high and possibly toxic concentrations can be achieved in blood and tissues due to accumulation. The degree of renal impairment should be controlled by determining serum creatinine or creatinine clearance.
As the effect of aminoglycosides is correlated to Cmax (see section 5.1), all patients are initially given a normal dose (15mg/kg body weight). In patients with mild to moderate renal impairment, the dosing interval is based on the trough value, see “Treatment control”. There are no data for recommendations for repeated dosing in patients with severe renal impairment, i.e. where an adequate trough value is not reached within 48 hours.
Haemodialysis:
The documentation for dosing in patients undergoing haemodialysis is deficient. Commonly used dosage is 5 mg/kg body weight given after each dialysis session.
Peritoneal dialysis:
Patients who undergo peritoneal dialysis twice a week are given 5 mg/kg body weight after each dialysis session. Patients who undergo peritoneal dialysis every other day are given 5 mg/kg after the first dialysis session and 2.5 mg/kg after the following dialysis sessions.
Other routes of administration
Amikacin in concentrations of 0.25 % (2.5 mg/ml) may be used satisfactorily as an irrigating solution in abscess cavities, the pleural space, the peritoneum and the cerebral ventricles.
Intraperitoneal use
Following exploration for established peritonitis, or after peritoneal contamination due to faecal spill during surgery, Amikacin may be used as an irrigant after recovery from anaesthesia in concentrations of 0.25 % (2.5 mg/ml). If instillation is desired in adults, a single dose of 500 mg is diluted in 20 ml of sterile distilled water and may be instilled through a polyethylene catheter sutured into the wound at closure. If possible, instillation should be postponed until the patient has fully recovered from the effects of anaesthesia and muscle-relaxing drugs.
Monitoring
The renal function status should be evaluated by measuring the serum creatinine concentration or preferably by estimation of creatinine clearance. Blood urea nitrogen (BUN) is far less reliable for this purpose. Assessment of renal function should be performed at the start of therapy and should be re-evaluated at regular intervals during treatment.
Amikacin concentrations in serum should be measured in all patients receiving parenteral amikacin and must be measured in obesity, if high doses are being given, the elderly and in cystic fibrosis. Both peak and trough serum concentrations should be measured intermittently during therapy to ensure adequate but not excessive serum levels. In patients receiving multiple daily dosing peak concentrations (30-90 minutes after injection) of above 35 μg/ml and trough concentrations (just before the next dose) of above 10 μg/ml should be avoided.
In patients receiving once daily (or extended interval) dosing pre-dose ('trough') concentration should be less than 5 mcg/ml. Peak concentrations (approximately 60 minutes after administration) may exceed 35 mcg/ml.
If the pre-dose ('trough') concentration is high, the interval between doses must be increased. If the post-dose ('peak') concentration is high, the dose must be decreased.
Auditory and vestibular function should also be monitored during treatment, in particular if longer treatment duration (>7-10 days) is considered.
Dosage in renal impairment:
NOTE: In patients with impaired renal function (creatinine clearance <50 ml/min) the recommended dose has to be decreased and adjusted to the renal function. This can be achieved by increasing the dose interval and/or reducing the dose.
In all patients with renal impairment, serum amikacin peak and trough concentration and renal function must be monitored regularly and the dose regimen altered as necessary (see below).
Once daily/extended interval dosing
Patients with renal impairment in whom once daily dosing would be considered appropriate if their renal function were normal may receive extended interval dosing.
The initial dose may be the same as in normal renal function. The dose interval should be at least 24 hours and extended according to the degree of renal impairment and the results of serum amikacin level measurements (see Monitoring Advice).
In severe renal impairment, the initial dose may have to be reduced in addition.
Once daily or extended interval dosing should be avoided in patients with a creatinine clearance less than 20 ml/minute.
A once daily/extended interval dose regimen should be avoided in children over 1 month of age with a creatinine clearance less than 20 ml/minute/1.73 m2.
Reduced dose at fixed intervals:
If patients with renal impairment are given amikacin at fixed time intervals, the dose must be reduced. In these patients, the serum amikacin concentration should be measured to ensure accurate administration and to avoid excessive serum concentrations. If a determination of serum concentration is not possible and the patient's condition is stable, serum creatinine and creatinine clearance rates are the most readily available indicators of the extent of renal dysfunction and the consequent reduction in dose.
As renal function may alter appreciably during therapy, the serum creatinine should be checked frequently and the dosage regimen modified as necessary.
Multiple daily dosing
In patients with renal impairment in whom multiple daily dosing at fixed intervals would be considered appropriate if their renal function were normal, the dose must be reduced while the dose interval is maintained. Serum amikacin concentrations should be measured and creatinine clearance should be estimated regularly (see Monitoring Advice).
Treatment should be initiated by administering a normal dose, 7.5 mg/kg, as a loading dose. This dose is the same as the normally recommended dose which would be calculated for a patient with a normal renal function as described above.
To initially determine the size of maintenance doses administered after 12 hours, the loading dose should be reduced in proportion to the reduction in the patient's creatinine clearance rate:

Subsequent doses should be determined based on amikacin serum concentrations (see Monitoring Advice).
Treatment duration
At recommended dosages, infections caused by susceptible pathogens should respond to therapy within 24-48 hours. If clinical response does not occur within 3-5 days, therapy should be discontinued and the antibiotic susceptibility pattern of the invading organism should be rechecked. If necessary, alternative therapy should be considered. Failure of therapy may be due to the resistance of the organism or to septic locus requiring surgical drainage.
The average duration of treatment is 7-10 days. For all routes of administration, the maximum daily dose should not exceed 15-20 mg/kg/day. If prolonged treatment is required, it should be carried out after reviewing the necessity of using amikacin, determination of serum amikacin concentrations and additionally monitoring of renal, auditory and vestibular functions as closely as possible daily.
Serum amikacin concentrations should be monitored to ensure therapeutic, but not excessively high, levels. It is recommended that serum samples be taken on the second day of treatment and then regularly, 2-3 times a week, during treatment.
Trough values (just before the next dosing session) should not exceed 10 micrograms/ml. A progressive increase in the trough value reveals an ongoing accumulation, in which case the dosing interval should be extended.
Amikacin, like other aminoglycosides, is potentially nephrotoxic and ototoxic. Renal function, hearing and balance should, if possible, be checked regularly during amikacin treatment. It is extremely important to follow the dosage recommendations and to keep the patient well hydrated.
Method of administration
IM use or IV use after dilution.
The solution for intravenous use is prepared by adding the desired dose to 100 ml or 200 ml of sterile diluent such as normal saline or 5 % dextrose in water or any other compatible solution. The solution is administered to adults over a 30 to 60-minute period.
In paediatric patients the amount of diluents used will depend on the amount of amikacin tolerated by the patient. The solution should, normally, be infused over a 30 to 60-minute period. Infants should receive a 1 to 2-hour infusion.
Amikacin should not be physically premixed with other drugs, but should be administered separately according to the recommended dose and route.
For the dilution of Amikacin see section 6.6.