Posology : מינונים

4.2 Posology and Method of Administration
Posology:
Usual Adult dosage:

Type of Infection Dose               Dose             Frequency frequency
Moderate to severe infections          500 mg to 1      every 6 to 8 hours gram

Mild infections caused by              250 mg to        every 8 hours susceptible gram -positive cocci       500 mg

Acute, uncomplicated urinary tract     1 gram           every 12 hours infections

Pneumococcal pneumonia                 500 mg           every 12 hours 
Severe, life -threatening infections   1 gram to 1.5    every 6 hours (e.g.,endocarditis , septicemia )*     grams

* In rare instances, doses of up to 12 grams per day have been used.

Perioperative Prophylactic Use: To prevent postoperative infection in contaminated or potentially contaminated surgery, recommended doses are:
 a. 1 gram IV or IM administered 1/2 hour to 1 hour prior to the start of surgery.
 b. For lengthy operative procedures (e.g., 2 hours or more), 500 mg to 1 gram IV or IM during surgery (administration modified depending on the duration of the operative procedure),
 c. 500 mg to 1 gram IV or IM every 6 to 8 hours for 24 hours postoperatively.

It is important that (1) the preoperative dose be given just (1/2 to 1 hour) prior to the start of surgery so that adequate antibiotic levels are present in the serum and tissues at the time of initial surgical incision; and (2) Cefazolin-Fresenius be administered, if necessary, at appropriate intervals during surgery to provide sufficient levels of the antibiotic at the anticipated moments of greatest exposure to infective organisms. The prophylactic administration of Cefazolin - Fresenius should usually be discontinued within a 24- hour period after the surgical procedure. In surgery where the occurrence of infection may be particularly devastating (e.g., open-heart surgery and prosthetic arthroplasty), the prophylactic administration of Cefazolin-Fresenius may be continued for 3 to 5 days following the completion of surgery.

If there are signs of infection, specimens for cultures should be obtained for the identification of the causative organism so that appropriate therapy may be instituted 
Dosage Adjustment for Patients with Reduced Renal Function: Cefazolin-Fresenius may be used in patients with reduced renal function with the following dosage adjustments: 
Crearinine clearance (ml        Serum creatinine (mg%)           Dosage /min)

55 or greater                  1.5 or less                      Full doses 
35 to 54                        1.6 to 3.0                       Full doses restricted to at least 8 hour intervals

11 to 34                        3.1 to 4.5                       1/2 of the usual dose every 12 hours

10 or less                      4.6 or greater                   1/2 of the usual dose every 18 to 24 hours

All reduced dosage recommendations apply after an initial loading dose appropriate to the severity of the infection. Patients undergoing peritoneal dialysis see section 5.2 Pharmacokinetic Properties.

Pediatric Dosage: In pediatric patients, a total daily dosage of 25 to 50 mg per kg (approximately 10 to 20 mg per pound) of body weight, divided into 3 or 4 equal doses, is effective for most mild to moderately severe infections. Total daily dosage may be increased to 100 mg per kg (45 mg per pound) of body weight for severe infections. Since safety for use in premature infants and in neonates has not been established, the use of Cefazolin- Fresenius in these patients is not recommended.

Pediatric Dosage Guide

Weight              25 mg/kg /day                             25 mg /kg /day Divided into 3 doses                      Divided into 4 doses

Lbs      Kg        Approximate           Vol.(ml)needed      Approximate      Vol.(ml) Single dose                               Single Dose      needed with With dilution of mg/q8h                                                     dilution of 125 125 mg/ml           mg/q6h mg/ml

10       4.5       40 mg                 0.35 ml             30 mg             0.25 ml 
20       9.0       75 mg                 0.60 ml              55 mg           0.45 ml

30       13.6      115 mg                0.90 ml             85 mg            0.70 ml 
40       18.1      150 mg                1.20 ml             115 mg           0.90 ml

50       22.7      190 mg                1.50 ml             140 mg           1.10 ml 


Weight              50 mg/kg /day                           50 mg /kg /day 
Divided into 3 doses                     Divided into 4 doses
 lbs      Kg        Approximate           Vol.(ml)needed     Approximate       Vol.(ml) Single dose                              Single Dose       needed with With dilution of mg/q8h                                                     dilution of 225 225 mg/ml          mg/q6h mg/ml

10       4.5        75 mg                0.35 ml            55 mg             0.25 ml 
20       9.0       150 mg                0.70 ml            110 mg             0.50 ml

30       13.6       225 mg               1.00 ml            170 mg            0.75 ml 
40       18.1       300 mg               1.35 ml             225 mg           1.00 ml

50       22.7      375 mg                1.70 ml            285 mg            1.25 ml 


In pediatric patients with mild to moderate renal impairment (creatinine clearance of 70 to 40 ml /min.), 60 percent of the normal daily dose given in equally divided doses every 12 hours should be sufficient. In patients with moderate impairment (creatinine clearance of 40 to 20 mL/min.), 25 percent of the normal daily dose given in equally divided doses every 12 hours should be adequate. Pediatric patients with severe renal impairment (creatinine clearance of 20 to 5 mL/min.) may be given 10 percent of the normal daily dose every 24 hours. All dosage recommendations apply after an initial loading dose.

Method of Administration:

Cefazolin may be administered by deep intramuscular injection, intravenously or by infusion.
IM Administration:

Intramuscular injection is contraindicated in children under the age of 30 months.

Dilute 1000mg of Cefazolin in 4 ml Lidocaine 0,5 % and administer by deep intramuscular injection. The reconstituted solution with 4 ml Lidocaine 0,5 % is stable for 24 hours below 25°C or 72 hours in the refrigerator (2° C - 8° C).

Reconstituted solution may present a yellow coloration that does not imply that the product potency is adversely affected.

IV Administration:

Cefazolin can be given by direct injection (bolus) or by continuous or intermittent infusion.
Do not use intravenously the solution reconstituted with lidocaine hydrochloride, which is specific for intramuscular administration.

Direct (bolus) IV injection:

Dilute 1000mg of Cefazolin in 10 ml of Water for injections or 4ml Sodium chloride 0.9% and administer slowly (3 to 5 minutes), directly in the vein or in the infusion system.

The reconstituted solution with 10 ml of Water for injections is stable for 24 hours below 25°C or 72 hours in the refrigerator (2° C - 8°C).

The reconstituted solution with 4 ml of Sodium chloride 0.9% is stable for 12 hours below 25°C or 72 hours in the refrigerator (2° C - 8°C).

Intermittent or continuous IV infusion.

Dilute 1000mg dosage of Cefazolin in 100 ml in one of the following intravenous solutions: 
-        Sodium chloride 0.9%

-        Dextrose 5%
In these intravenous solutions, Cefazolin is stable for 12 hours below 25°C.