Gentalek Gentamycin Product Characteristics

Gentalek Gentamycin Product Characteristics

The following information is intended for medical or health care providers only (short summary of product characteristics).

The solution is colourless to almost colourless, clear and free of visible particulate matter. Prior to administering, the solution for injection/infusion is to be carefully inspected to make sure, it is clear, does not contain precipitates and has not chnaged its colour. If the appearance of the product is changed do not use the solution for injection/infusion.

 

Incompatibilities

Beta-lactam antibiotics in vitro may inactivate gentamicin; therefore, they should not be mixed in the same infusion bottle for intravenous administration.

Penicillin should not be mixed directly with gentamicin due to physical and chemical incompatibility.

Gentamicin may be inactivated by some beta-lactam antibiotics in vitro and less frequently in vivo. This reaction is significant particularly when using carbenicillin and ticarcillin together with gentamicin. The reaction occurs mainly in vitro therefore, gentamicin and beta-lactam antibiotics should not be mixed in the same syringe or infusion bottle.

 

Special precautions for disposal and other handling

Any unused product or waste material should be disposed of in accordance with local requirements.

Gentamicin for short-term intravenous infusion is to be diluted

– in 100 ml of sodium chloride 9 mg/ml (0.9%) solution for injection.

– or glucose 50 mg/mI (5%) solution or infusion.

The concentration of gentamicin in the solution should not exceed 1 mg/ml.

 

Posology and administration

Gentamidn is intended for intramuscular as well as intravenous administration. The dose, route of administration and interval between individual doses depend on the type and severity of the infection, the susceptibility of the microorganism and the patient’s condition (age, renal function).

Administration of the product as a single daily dose produces a stronger antibacterial effect due to a higher concentration of gentamicin. The antibacterial effect of the following dose is also more expressed due to a prolonged interval.

The exact dose is determined on the basis of the patient’s body weight. The medicine should not be administered as a single daily dose in patients with impaired immunity, severe renal impairment, infective endocarditis and in pregnant women.

Adults and children above 12 years of age: The usual daily dose of gentamicin in patients with moderate infections is 3 mg/kg body weight, administered intramuscularly or intravenously and divided into one to three doses. The usual dose in patients above 60 kg with normal renal function is 80 mg every 8 hours. In severe infections the dose is increased to 5 mg/kg daily.

Infants and children from 1 to 12 years of age: 4.5 mg to 6 mg/kg/day intramuscularly or intravenously, divided into one to three doses.

Newborn infants older than one week and infants up to one year of age: 6 mg/kg/day intramuscularly or intravenously divided into two doses (administered every 12 hours).

Newborn infants in the first week of life: 5 mg/kg/day intramuscularly or intravenously divided into two doses (administered every 12 hours).

Newborn infants should be given gentamicin only in urgent cases. The treatment should be as short as possible.

In newborn infants, infants and in children being administered equal doses determined on the basis of their body weight, serum concentrations of gentamicin are lower than in adults; consequently, the doses are slightly higher. It is recommended to determine serum concentrations of gentamicin every day. The serum concentration of gentamicin one hour after administration should be at least 4 micrograms/ml.

 

Administration in renal Impairment

An altered dosage schedule of gentamicin is required in the presence of renal failure. The initial dose is the same as in patients with normal renal function; however, during the continuation of the treatment the interval between individual doses should be prolonged.

As the aminoglycoside clearance is highly correlated with the creatinine clearance, the required gentamicin dose may be calculated on the basis of creatinine clearance values.
The following table provides the recommended dosage schedules in patients with impaired renal function:

Urea
mg/100 ml
Creatinine clearance
(ml/s)
Doses and dosage
interval
< 40 > 1.2 80* mg every 8 hours
40 – 100 0.5 – 1.2 80* mg every 12 hours
100 – 200 0.2 – 0.5 80*mg every 24 hours
> 200 0.1 – 0.2 80* mg every 48 hours
haemodialysis
twice a week
< 0.1 80 mg after dialysis

* in patients weighing less than 60 kg, 60 mg of gentamicin should be administered.
When determining gentamicin doses, it should be borne in mind that these doses are only approximate and that equal doses may produce different concentrations in different patients. Consequently, serum gentamicin concentrations should be determined and the doses should be adjusted accordingly. The serum level of gentamicin 30 to 60 minutes after intravenous or intramuscular application should be 5 – 10 micrograms/ml.
1 to 1.5 mg of gentamicin per kg body weight should be administered at the end of haemodialysis. In peritoneal dialysis, 1 mg of gentamicin should be added to 2 litres of dialysis solution.

 

Elderly patients

In elderly patients, the half-life of gentamicin is prolonged due to a decreased glomerular filtration rate. The decreased glomerular filtration rate in elderly patients is not always manifested in higher levels of serum creatinine. Consequently, the creatinine clearance should be determined in elderly patients in order to calculate the gentamicin dose.

 

Method of intravenous administration

The doses are identical as in intramuscular administration.

Gentamicin should be administered directly intravenously in a slow manner (3-5 minutes, though no longer than 15 minutes) or as a slow infusion (30-60 minutes). The maximum dose for direct intravenous administration in adult patients is 80 mg of gentamicin; if the dose is higher, a short-term infusion is required.

When Gentamicin is administered as a short-term infusion, the usual quantity of the solvent (sodium chloride 9 mg/ml (0.9%) solution for injection or glucose 50 mg/ml (5%) solution for infusion) is 100 ml in adults and proportionately less in children, depending on the dose. The concentration of gentamicin in the infusion is 20-30 minutes when the medicine is administered several times a day.

When the medicine is administered as a single daily dose, the duration of infusion is 30-60 minutes.

The maximum daily dose of gentamicin is 7.5 mg/kg divided into three doses.