Each vial contains in 2 ml amikacin sulphate equivalent to amikacin activity 100mg (100,000 international units).

Solution for administration to human beings by injection.

Amikacin sulphate is an aminoglycoside antibiotic which is active against a broad spectrum of Gram-negative organisms, including Pseudomonas spp., Escherichia coli, indole-positive and indole-negative Proteus spp. Klebsiella-Enterobacter-Serratia spp, Salmonella, Shigella, Minea-Herellae, Citrobacter freundii and Providencia spp.

Many strains of these gram-negative organisms resistant to gentamicin and tobramycin may show sensitivity to amikacin in vitro. The principal Gram-positive organism sensitive to amikacin is Staphylococcus aureus, including methicillin-resistant strains. Amikacin has some activity against other Gram-positive organisms including certain strains of Streptococcus pyogenes, Enterococci and Diplococcus pneumoniae.

Amikin is indicated in the short-term treatment of serious infections due to susceptible strains of Gram-negative bacteria. It may also be indicated for the treatment of known or suspected staphylococcal disease.

For most infections the intramsucular route is preferred, but in life-threatening infections, or in patients in whom intramuscular injection is not feasible the intravenous route, either slow bolus (2 to 3 minutes) or infusion (0.25% over 30 minutes) may be used.

Intramuscular and intravenous administration

At the recommended dosage level, uncomplicated infections due to sensitive organisms should respond to therapy within 24 to 48 hours.

If clinical response does not occur within three to five days consideration should be given to alternative therapy.

Adults and children

15mg/kg/day in two equally divided doses (equivalent to 500mg b.i.d. in adults): use of the 100mg/2ml strength is recommended for children for the accurate measurement of the appropriate dose.

Neonates and premature infants

An initial loading dose of 10mg/kg followed by 15mg/kg/day in two equally divided doses.

Elderly

Amikacin is excreted by the renal route. Renal function should be assessed whenever possible and dosage adjusted as described under impaired renal function.

Life-threatening infections and/or those caused by Pseudomonas

The adult dose may be increased to 500mg every eight hours but should neither exceed 1.5g/day nor be administered for a period longer than 10 days. A maximum total adult dose of 15g should not be exceeded.

Urinary tract infections: (other than pseudomonal infections)

7.5mg/kg/day in two equally divided doses (equivalent to 250mg b.i.d. in adults). As the activity of amikacin is enhanced by increasing the pH, a urinary alkalising agent may be administered concurrently.

Impaired renal function

In patients with impaired renal function, the daily dose should be reduced and/or the intervals between doses increased to avoid accumulation of the drug. A suggested method for estimating dosage in patients with known or suspected diminished renal function is to multiply the serum creatinine concentration (in mg/100ml) by 9 and use the resulting figure as the interval in hours between doses.

As renal function may alter appreciably during therapy, the serum creatinine should be checked frequently and the dosage regimen modified as necessary.

Intraperitoneal use

Following exploration for established peritonitis, or after peritoneal contamination due to faecal spill during surgery, Amikin may be used as an irrigant after recovery from anaesthesia in concentrations of 0.25% (2.5mg/ml). If instillation is desired in adults, a single dose of 500mg is diluted in 20ml 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.

Other routes of administration

Amikin in concentrations of 0.25% may be used satisfactorily as an irrigating solution in abscess cavities, the pleural space, the peritoneum and the cerebral ventricles.

Hypersensitivity to any of the components of the product.

Myasthenia gravis.

Patients should be well hydrated during amikacin therapy.

In patients with impaired renal function or diminished glomerular filtration, amikacin should be used cautiously. In such patients, renal function should be assessed by the usual methods prior to therapy and periodically during therapy. Daily doses should be reduced and/or the interval between doses lengthened in accordance with serum creatinine concentrations to avoid accumulation of abnormally high blood levels and to minimise the risk of ototoxicity.

As with other aminoglycosides, ototoxicity and/or nephrotoxicity can result from the use of amikacin; precautions on dosage and adequate hydration should be observed.

If signs of renal irritation appear (such as albumin, casts, red or white blood cells), hydration should be increased and a reduction in dosage may be desirable. These findings usually disappear when treatment is completed. However, if azotaemia or a progressive decrease in urine output occurs, treatment should be stopped.

The use of amikacin in patients with a history of allergy to aminoglycosides or in patients who may have subclinical renal or eighth nerve damage induced by prior administration of nephrotoxic and/or ototoxic agents such as streptomycin, dihydrostreptomycin, gentamicin, tobramycin, kanamycin, bekanamycin, neomycin, polymyxin B, colistin, cephaloridine, or viomycin should be considered with caution, as toxicity may be additive.

In these patients amikacin should be used only if, in the opinion of the physician, therapeutic advantages outweigh the potential risks.

Aminoglycosides may impair neuromuscular transmission and should be used with caution in patients with muscular disorders such as parkinsonism. Large doses given during surgery have been responsible for a transient myasthenic syndrome.

The intraperitoneal use of amikacin is not recommended in young children.

Concurrent use with other potentially nephrotoxic or ototoxic drug substances should be avoided. Where this is not possible, monitor carefully.The risk of ototoxicity is increased when amikacin is used in conjunction with rapidly acting diuretic drugs, particularly when the diuretic is administered intravenously. Such agents include frusemide and ethacrynic acid which is itself an ototoxic agent. Irreversible deafness may result.

The intraperitoneal use of amikacin is not recommended in patients under the influence of anaesthetics or muscle-relaxing drugs (including ether, halothane, dtubocurarine, succinylcholine and decamethonium) as neuromuscular blockade and consequent respiratory depression may occur.

Indomethacin may increase the plasma concentration of amikacin in neonates.

In patients with severely impaired renal function, a reduction in activity of aminoglycosides may occur with concomitant use of penicillin-type drugs.

When the recommended precautions and dosages are followed the incidence of toxic reactions, such as tinnitus, vertigo, partial reversible or irreversible deafness, skin rash, drug fever, headache, paraesthesia, nausea and vomiting is low. Urinary signs of renal irritation (albumin, casts and red or white blood cells), azotaemia and oliguria have been reported. There have been reports of retinal toxicity following intravitreal injection of amikacin.

Bristol-Myers Pharmaceuticals

POM – Prescription Only Medicine

05 May 2010