Posology : מינונים

Dosage and Administration
Ceftazidime is to be used by the parenteral route, the dosage depending upon the severity, sensitivity, site and type of infection and the age, weight and renal function of the patient. Ceftazidime may be given intravenously or by deep intramuscular injection into a large muscle mass such as the upper outer quadrant of the gluteus maximus or lateral part of the thigh. Ceftazidime solutions may be given directly into the vein or introduced into the tubing of a giving set if the patient is receiving parenteral fluids.


CEFTAZIDIME TEVA,            7. 6. 2015, RH
Populations
Adults:
The adult dosage range for ceftazidime is 1 to 6 g per day 8 or 12 hourly (i.m. or i.v.).
In the majority of infections, 1 g 8-hourly or 2 g 12-hourly should be given.

In urinary tract infections, and in many less serious infections, 500 mg or 1 g 12- hourly is usually adequate.
In very severe infections, especially immunocompromised patients, including those with neutropenia, 2 g 8 or 12-hourly or 3 g 12-hourly should be administered.

When used as a prophylactic agent in prostatic surgery, 1 g (from the 1 g bottle) should be given at the induction of anaesthesia. A second dose should be considered at the time of catheter removal.

Elderly:
In view of the reduced clearance of ceftazidime in acutely ill elderly patients, the daily dosage should not normally exceed 3 g, especially in those over 80 years of age.

Cystic fibrosis:
In fibrocystic adults with normal renal function who have pseudomonal lung infections, high doses of 100 to 150 mg/kg/day as three divided doses should be used.
In adults with normal renal function 9 g/day has been used without ill effect.

Infants and children (greater than 2 months):
The usual dosage range for children aged over two months is 30 to 100 mg/kg/day, given as two or three divided doses.
Doses up to 150 mg/kg/day (maximum 6 g daily) in three divided doses may be given to infected immunocompromised or fibrocystic children or children with meningitis.

Neonates and children up to 2 months of age:
Whilst clinical experience is limited, a dose of 25 to 60 mg/kg/day given as two divided doses has proved to be effective. In the neonate the serum half-life of ceftazidime can be three to four times that in adults.

Renal impairment:
Ceftazidime is excreted by the kidneys. Therefore, in patients with impaired renal function it is recommended that the dosage of ceftazidime should be reduced to compensate for its slower excretion, except in mild impairment, i.e. glomerular filtration rate (GFR) greater than 50 ml/min. In patients with suspected renal insufficiency, an initial loading dose of 1 g of ceftazidime may be given. An estimate of GFR should be made to determine the appropriate maintenance dose.

Recommended maintenance doses are shown in the next column:
Recommended maintenance doses of ceftazidime in renal insufficiency Creatinine       Approx. serum    Recommended unit         Frequency of clearance       creatinine µmol/l dose of ceftazidime     dosing (hourly) ml/min             (mg/dl)               (g)
>50             <150(<1.7)       Normal dosage
50-31        150-200 (1.7-2.3)            1                   12 30-16        200-350 (2.3-4.0)            1                   24 15-6        350-500 (4.0-5.6)           0.5                  24
<5            >500 (>5.6)              0.5                  48
* These values are guideline and may not accurately predict renal function in all patients especially in the elderly in whom the serum creatinine concentration may overestimate renal function.


CEFTAZIDIME TEVA,              7. 6. 2015, RH                                     Page 2 of 12 
In patients with severe infections, especially in neutropenics, who would normally receive 6 g of ceftazidime daily were it not for renal insufficiency, the unit dose given in the table above may be increased by 50% or the dosing frequency increased appropriately. In such patients it is recommended that ceftazidime serum levels should be monitored and trough levels should not exceed 40 mg/litre.


When only serum creatinine is available, the following formula (Cockcroft’s equation) may be used to estimate creatinine clearance. The serum creatinine should represent a steady state of renal function:

Males:
Creatinine clearance (ml/min) =             weight (kg) x (140 - age in years) 72 x serum creatinine (mg/dl)

Females: 0.85 x above value.

To convert serum creatinine in µmol/litre into mg/dl divide by 88.4.
In children the creatinine clearance should be adjusted for body surface area or lean body mass and the dosing frequency reduced in cases of renal insufficiency as for adults.

Haemodialysis:
The serum half-life of ceftazidime during haemodialysis ranges from 3 to 5 hours.
The appropriate maintenance dose of ceftazidime recommended in the above table should be repeated following each haemodialysis period.

Peritoneal dialysis:
Ceftazidime may also be used in peritoneal dialysis and continuous ambulatory peritoneal dialysis (CAPD).
As well as using ceftazidime intravenously, it can be incorporated into the dialysis fluid (usually 125 to 250 mg for 2 L of dialysis fluid).
For patients in renal failure on continuous arteriovenous haemodialysis or high-flux haemofiltration in intensive therapy units, it is recommended that the dosage should be 1 g daily either as a single dose or in divided doses. For low-flux haemofiltration it is recommended that the dosage should be that suggested under impaired renal function.
For patients on venovenous haemofiltration and venovenous haemodialysis, follow the dosage recommendations in the tables below:

Continuous venovenous haemofiltration dosage guidelines for ceftazidime Residual renal function  Maintenance dose (mg) for an ultrafiltration rate a
(creatinine clearance in                   (ml/min) of : ml/min)            5            16.7          33.3           50
0              250            250          500           500
5              250            250          500           500
10              250            500          500           750
15              250            500          500           750
20              500            500          500           750 a
Maintenance dose to be administered every 12 h.


CEFTAZIDIME TEVA,               7. 6. 2015, RH                             Page 3 of 12 
Ceftazidime dosage guidelines during continuous venovenous haemodialysis Residual renal function        Maintenance dose (mg) for a dialysate in flow rate of a: (creatinine clearance in               1.0 litre/h                    2.0 litres/h ml/min)             Ultrafiltration rate (litre/h) Ultrafiltration rate (litres/h) 0.5         1.0           2.0   0.5          1.0          2.0
0              500         500           500    500         500           750 5              500         500           750    500         500           750 10              500         500           750    500         750          1000 15              500         750           750    750         750          1000                20              750         750           1000   750         750          1000 a
Maintenance dose to be administered every 12 h.