Amikacin Sulfate - Amikacin Sulfate injection, Solution

Patients treated with parenteral aminoglycosides should be under close clinical observation because of the potential ototoxicity and nephrotoxicity associated with their use. Safety for treatment periods which are longer than 14 days has not been established.

Neurotoxicity, manifested as vestibular and permanent bilateral auditory ototoxicity, can occur in patients with preexisting renal damage and in patients with normal renal function treated at higher doses and/or for periods longer than those recommended. The risk of aminoglycoside-induced ototoxicity is greater in patients with renal damage. High frequency deafness usually occurs first and can be detected only by audiometric testing. Vertigo may occur and may be evidence of vestibular injury. Other manifestations of neurotoxicity may include numbness, skin tingling, muscle twitching and convulsions. The risk of hearing loss due to aminoglycosides increases with the degree of exposure to either high peak or high trough serum concentrations. Patients developing cochlear damage may not have symptoms during therapy to warn them of developing eighth-nerve toxicity, and total or partial irreversible bilateral deafness may occur after the drug has been discontinued. Aminoglycoside-induced ototoxicity is usually irreversible. Aminoglycosides are potentially nephrotoxic. The risk of nephrotoxicity is greater in patients with impaired renal function and in those who receive high doses or prolonged therapy.

Neuromuscular blockade and respiratory paralysis have been reported following parenteral injection, topical instillation (as in orthopedic and abdominal irrigation or in local treatment of empyema), and following oral use of aminoglycosides. The possibility of these phenomena should be considered if aminoglycosides are administered by any route, especially in patients receiving anesthetics, neuromuscular blocking agents such as tubocurarine, succinylcholine, decamethonium, or in patients receiving massive transfusions of citrate-anticoagulated blood. If blockage occurs, calcium salts may reverse these phenomena, but mechanical respiratory assistance may be necessary.

Renal and eighth-nerve function should be closely monitored especially in patients with known or suspected renal impairment at the onset of therapy and also in those whose renal function is initially normal but who develop signs of renal dysfunction during therapy. Serum concentrations of amikacin should be monitored when feasible to assure adequate levels and to avoid potentially toxic levels and prolonged peak concentrations above 35 micrograms per mL. Urine should be examined for decreased specific gravity, increased excretion of proteins, and the presence of cells or casts. Blood urea nitrogen, serum creatinine, or creatinine clearance should be measured periodically. Serial audiograms should be obtained where feasible in patients old enough to be tested, particularly high risk patients. Evidence of ototoxicity (dizziness, vertigo, tinnitus, roaring in the ears, and hearing loss) or nephrotoxicity requires discontinuation of the drug or dosage adjustment.

Concurrent and/or sequential systemic, oral or topical use of other neurotoxic or nephrotoxic products, particularly bacitracin, cisplatin, amphotericin B, cephaloridine, paromomycin, viomycin, polymyxin B, colistin, vancomycin, or other aminoglycosides should be avoided. Other factors that may increase risk of toxicity are advanced age and dehydration.

The concurrent use of amikacin with potent diuretics (ethacrynic acid, or furosemide) should be avoided since diuretics by themselves may cause ototoxicity. In addition, when administered intravenously, diuretics may enhance aminoglycoside toxicity by altering antibiotic concentrations in serum and tissue.

Amikacin Sulfate Injection USP is indicated in the short-term treatment of serious infections due to susceptible strains of Gram-negative bacteria, including

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 post-operative 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

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 staphylococci/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 antibacterial therapy.

In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

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 to 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.

Since the vials are for single-dose only, any unused portion remaining in the vial should be discarded.

The recommended dosage for adults, children and older infants (see

When amikacin is indicated in newborns (see

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 reevaluated. 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.

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.

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.

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:

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.

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 or 200 mL of sterile diluent such as 0.9% sodium chloride injection or 5% dextrose injection 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 of amikacin ordered for the patient. It should be a sufficient amount to infuse the Amikacin Sulfate Injection USP 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.

Amikacin sulfate is stable for 24 hours at room temperature at concentrations of 0.25 and 5 mg/mL in the following solutions:

5% Dextrose Injection

5% Dextrose and 0.2% Sodium Chloride Injection

5% Dextrose and 0.45% Sodium Chloride Injection

0.9% Sodium Chloride Injection

Lactated Ringer's Injection

Normosol^® M in 5% Dextrose Injection (or Plasma-Lyte 56 Injection in 5% Dextrose in Water)

Normosol^® R in 5% Dextrose Injection (or Plasma-Lyte 148 Injection in 5% Dextrose in Water)

In the above solutions with Amikacin Sulfate Injection USP concentrations of 0.25 and 5 mg/mL, solutions aged for 60 days at 4°C and then stored at 25°C had utility times of 24 hours.

At the same concentrations, solutions frozen and aged for 30 days at - 15°C, thawed, and stored at 25°C had utility times of 24 hours.Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration whenever  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.

All aminoglycosides have the potential to induce auditory, vestibular, and renal toxicity and neuromuscular blockade (see

Toxic effects on the eighth cranial nerve can result in hearing loss, loss of balance, or both. Amikacin primarily affects auditory function. Cochlear damage includes high frequency deafness and usually occurs before clinical hearing loss can be detected.

Acute muscular paralysis and apnea can occur following treatment with aminoglycoside drugs.

Elevation of serum creatinine, albuminuria, presence of red and white cells, casts, azotemia, and oliguria have been reported. Renal function changes are usually reversible when the drug is discontinued. As would be expected with any aminoglycoside, reports of toxic nephropathy and acute renal failure have been received during postmarketing surveillance.

In addition to those described above, other adverse reactions which have been reported on rare occasions are skin rash, drug fever, headache, paresthesia, tremor, nausea and vomiting, eosinophilia, arthralgia, anemia, hypotension and hypomagnesemia. Macular infarction sometimes leading to permanent loss of vision has been reported following intravitreous administration (injection into the eye) of amikacin.

Amikacin sulfate is semi-synthetic aminoglycoside antibiotic derived from kanamycin. It is C₂₂H₄₃N₅O₁₃•2H₂SO₄•

The dosage form is supplied as a sterile, colorless to light straw colored solution for intramuscular or intravenous use. The 500 mg per 2 mL vial and 1 gram per 4 mL vial contains per each mL: 250 mg Amikacin (as the Amikacin sulfate USP), 0.66% sodium metabisulfite as an antioxidant, 2.5% sodium citrate dihydrate as a buffering agent with pH adjusted to 4.5 with sulfuric acid.