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Amikacin (Amikacin Sulfate) - Indications and Dosage

 
 



INDICATIONS AND USAGE

Amikacin Sulfate Injection, USP is indicated in the short-term treatment of serious infections due to susceptible strains of Gram-negative bacteria, including Pseudomonas species, Escherichia coli, species of indole-positive and indole-negative Proteus, Providencia species, Klebsiella-Enterobacter-Serratia species, and Acinetobacter (Mima-Herellea) species.

Clinical studies have shown Amikacin Sulfate Injection, USP to be effective in bacterial septicemia (including neonatal sepsis); in serious infections of the respiratory tract, bones and joints, central nervous system (including meningitis) and skin and soft tissue; intra-abdominal infections (including peritonitis); and in burns and postoperative infections (including post-vascular surgery). Clinical studies have shown amikacin also to be effective in serious complicated and recurrent urinary tract infections due to these organisms. Aminoglycosides, including Amikacin Sulfate Injection, USP, are not indicated in uncomplicated initial episodes of urinary tract infections unless the causative organisms are not susceptible to antibiotics having less potential toxicity.

Bacteriologic studies should be performed to identify causative organisms and their susceptibilities to amikacin. Amikacin may be considered as initial therapy in suspected Gram-negative infections and therapy may be instituted before obtaining the results of susceptibility testing. Clinical trials demonstrated that amikacin was effective in infections caused by gentamicin and/or tobramycin-resistant strains of Gram-negative organisms, particularly Proteus rettgeri, Providencia stuartii, Serratia marcescens, and Pseudomonas aeruginosa. The decision to continue therapy with the drug should be based on results of the susceptibility tests, the severity of the infection, the response of the patient and the important additional considerations contained in the “WARNINGS” box above.

Amikacin has also been shown to be effective in staphylococcal infections and may be considered as initial therapy under certain conditions in the treatment of known or suspected staphylococcal disease such as, severe infections where the causative organism may be either a Gram-negative bacterium or a staphylococcus, infections due to susceptible strains of staphylococci in patients allergic to other antibiotics, and in mixed staphylococcal/Gram-negative infections.

In certain severe infections such as neonatal sepsis, concomitant therapy with a penicillin-type drug may be indicated because of the possibility of infections due to Gram-positive organisms such as streptococci or pneumococci.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of amikacin and other antibacterial drugs, amikacin should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antimicrobial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

DOSAGE AND ADMINISTRATION

The patient’s pretreatment body weight should be obtained for calculation of correct dosage. Amikacin Sulfate Injection, USP may be given intramuscularly or intravenously.

The status of renal function should be estimated by measurement of the serum creatinine concentration or calculation of the endogenous creatinine clearance rate. The blood urea nitrogen (BUN) is much less reliable for this purpose. Reassessment of renal function should be made periodically during therapy.

Whenever possible, amikacin concentrations in serum should be measured to assure adequate but not excessive levels. It is desirable to measure both peak and trough serum concentrations intermittently during therapy. Peak concentrations (30-90 minutes after injection) above 35 micrograms per mL and trough concentrations (just prior to the next dose) above 10 micrograms per mL should be avoided. Dosage should be adjusted as indicated.

Intramuscular Administration for Patients with Normal Renal Function -The recommended dosage for adults, children and older infants (see “WARNINGS” box) with normal renal function is 15 mg/kg/day divided into 2 or 3 equal doses administered at equally-divided intervals, i.e., 7.5 mg/kg q.12h or 5 mg/kg q.8h. Treatment of patients in the heavier weight classes should not exceed 1.5 gram/day.

When amikacin is indicated in newborns (see “WARNINGS” box), it is recommended that a loading dose of 10 mg/kg be administered initially to be followed with 7.5 mg/kg every 12 hours.

The usual duration of treatment is 7 to 10 days. It is desirable to limit the duration of treatment to short term whenever feasible. The total daily dose by all routes of administration should not exceed 15 mg/kg/day. In difficult and complicated infections where treatment beyond 10 days is considered, the use of amikacin should be re-evaluated. If continued, amikacin serum levels and renal, auditory, and vestibular functions should be monitored. At the recommended dosage level, uncomplicated infections due to amikacin-sensitive organisms should respond in 24 to 48 hours. If definite clinical response does not occur within 3 to 5 days, therapy should be stopped and the antibiotic susceptibility pattern of the invading organism should be rechecked. Failure of the infection to respond may be due to resistance of the organism or to the presence of septic foci requiring surgical drainage.

When amikacin is indicated in uncomplicated urinary tract infections, a dose of 250 mg twice daily may be used.

DOSAGE GUIDELINES

ADULTS AND CHILDREN WITH NORMAL RENAL FUNCTION

Patient Weight

Dosage

7.5 mg/kg

5 mg/kg

lbs.

kg

q12h

OR

q8h

99

45

337.5 mg

225 mg

110

50

375 mg

250 mg

121

55

412.5 mg

275 mg

132

60

450 mg

300 mg

143

65

487.5 mg

325 mg

154

70

525 mg

350 mg

165

75

562.5 mg

375 mg

176

80

600 mg

400 mg

187

85

637.5 mg

425 mg

198

90

675 mg

450 mg

209

95

712.5 mg

475 mg

220

100

750 mg

500 mg

Intramuscular Administration for Patients with Impaired Renal Function -Whenever possible, serum amikacin concentrations should be monitored by appropriate assay procedures. Doses may be adjusted in patients with impaired renal function either by administering normal doses at prolonged intervals or by administering reduced doses at a fixed interval.

Both methods are based on the patient’s creatinine clearance or serum creatinine values since these have been found to correlate with aminoglycoside half-lives in patients with diminished renal function. These dosage schedules must be used in conjunction with careful clinical and laboratory observations of the patient and should be modified as necessary. Neither method should be used when dialysis is being performed.

Normal Dosage at Prolonged Intervals - If the creatinine clearance rate is not available and the patient’s condition is stable, a dosage interval in hours for the normal dose can be calculated by multiplying the patient’s serum creatinine by 9, e.g., if the serum creatinine concentration is 2 mg/100 mL, the recommended single dose (7.5 mg/kg) should be administered every 18 hours.

Reduced Dosage at Fixed Time Intervals - When renal function is impaired and it is desirable to administer amikacin at a fixed time interval, dosage must be reduced. In these patients serum amikacin concentrations should be measured to assure accurate administration of amikacin and to avoid concentrations above 35 mcg/mL. If serum assay determinations are not available and the patient’s condition is stable, serum creatinine and creatinine clearance values are the most readily available indicators of the degree of renal impairment to use as a guide for dosage.

First, initiate therapy by administering a normal dose, 7.5 mg/kg, as a loading dose. This loading 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 determine the size of maintenance doses administered every 12 hours, the loading dose should be reduced in proportion to the reduction in the patient’s creatinine clearance rate:

Maintenance Dose

=

observed CC in mL/min

x

calculated loading

Every 12 Hours

normal CC in mL/min

dose in mg

(CC−creatinine clearance rate)

An alternate rough guide for determining reduced dosage at 12 hour intervals (for patients whose steady state serum creatinine values are known) is to divide the normally recommended dose by the patient’s serum creatinine.

The above dosage schedules are not intended to be rigid recommendations but are provided as guides to dosage when the measurement of amikacin serum levels is not feasible.

Intravenous Administration -The individual dose, the total daily dose, and the total cumulative dose of amikacin sulfate are identical to the dose recommended for intramuscular administration. The solution for intravenous use is prepared by adding the contents of a 500 mg vial to 100-200 mL of sterile diluent such as 0.9% Sodium Chloride Injection, USP or 5% Dextrose Injection, USP or any of the compatible solutions listed below.

The solution is administered to adults over a 30 to 60 minute period. The total daily dose should not exceed 15 mg/kg/day and may be divided into either 2 or 3 equally-divided doses at equally-divided intervals.

In pediatric patients the amount of fluid used will depend on the amount ordered for the patient. It should be a sufficient amount to infuse the amikacin over a 30 to 60 minute period. Infants should receive a 1 to 2 hour infusion.

Stability in I.V. Fluids -Amikacin sulfate is stable for 24 hours at room temperature at concentrations of 0.25 and 5.0 mg/mL in the following solutions:

5% Dextrose Injection, USP

5% Dextrose and 0.2% Sodium Chloride Injection, USP

5% Dextrose and 0.45% Sodium Chloride Injection, USP

0.9% Sodium Chloride Injection, USP

Lactated Ringer’s Injection, USP

Normosol®-M in 5% Dextrose Injection

Normosol®-R in 5% Dextrose Injection

Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration whenever the solution and container permit.

Aminoglycosides administered by any of the above routes should not be physically premixed with other drugs but should be administered separately.

Because of the potential toxicity of aminoglycosides, “fixed dosage”recommendations which are not based upon body weight are not advised. Rather, it is essential to calculate the dosage to fit the needs of each patient.

To prevent needle-stick injuries, needles should not be recapped, purposely bent, or broken by hand.

HOW SUPPLIED

Amikacin Sulfate Injection, USP is supplied as a colorless solution which requires no refrigeration. At times the solution may become a light straw yellow; this does not indicate a decrease in potency.

List No.

Package/Volume

Amikacin Content

1955

Fliptop Vial/2 mL

100 mg (50 mg/mL)

1956

Fliptop Vial/2 mL

500 mg (250 mg/mL)

1957

Fliptop Vial/4 mL

1 g (250 mg/mL)

Store at 20-25°C (68-77°F) [See USP Controlled Room Temperature]

*Bauer, A.W., Kirby, W.M.M., Sherris, J.C., and Turck, M.: Antibiotic Testing by a Standardized Single Disc Method. Am.J.Clin.Pathol., 45:493, 1966; Standardized Disc Susceptibility Test, FEDERAL REGISTER, 37:20527-29, 1972.

©Hospira 2004

EN-0051

Printed in USA

HOSPIRA, INC., LAKE FOREST, IL 60045 USA

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