2.1 Adult Population
The recommended adult dosages are outlined in Table 1. Cefazolin for Injection should be administered intramuscularly (IM) or intravenously (IV) over approximately 30 minutes.
Table 1: Recommended Dosing Schedule in Adult Patients with CrCl Greater Than or Equal To 55 mL/min.
Site and Type of Infection
Dose
Frequency
Moderate to severe infections
500 mg to 1 gram
every 6 to 8 hours
Mild infections caused by susceptible gram-positive cocci
250 mg to 500 mg
every 8 hours
Acute, uncomplicated urinary tract infections
1 gram
every 12 hours
Pneumococcal pneumonia
500 mg
every 12 hours
Severe, life-threatening infections (e.g., endocarditis, septicemia)*
1 gram to 1.5 grams
every 6 hours
2.2 Perioperative Prophylactic Use
To prevent postoperative infection in contaminated or potentially contaminated surgery, recommended doses are:
1 gram IV or IM administered ½ hour to 1 hour prior to the start of surgery.
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).
500 mg to 1 gram IV or IM every 6 to 8 hours for 24 hours postoperatively.
It is important that (i) the preoperative dose be given just prior (1/2 hour to 1 hour) to the start of surgery so that adequate antibacterial concentrations are present in the serum and tissues at the time of initial surgical incision; and (ii) Cefazolin for Injection be administered, if necessary, at appropriate intervals during surgery to provide sufficient concentrations of the antibacterial drug at the anticipated moments of greatest exposure to infective organisms.
The prophylactic administration of Cefazolin for Injection 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 may be continued for 3 to 5 days following the completion of surgery.
2.3 Patients with Renal Impairment
Cefazolin for Injection may be used in patients with renal impairment with the dosage adjustments outlined in Table 2. All reduced dosage recommendations apply after an initial loading dose appropriate to the severity of the infection.
Table 2: Dosage Adjustment for Patients with Renal Impairment
Creatinine Clearance
Dose
Frequency
55 mL/min. or greater
full dose
normal frequency
35 to 54 mL/min.
full dose
every 8 hours or longer
11 to 34 mL/min.
1/2 usual dose
every 12 hours
10 mL/min. or less
1/2 usual dose
every 18 to 24 hours
2.4 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 for Injection in these patients is not recommended.
Table 3: Pediatric Dosage Guide
Weight
25 mg/kg/day
Divided into 3 Doses
25 mg/kg/day
Divided into 4 Doses
Lbs
Kg
Approximate Single Dose mg/q 8 h
Vol. (mL) needed with dilution of
125 mg/mL
Approximate Single Dose mg/q 6 h
Vol. (mL) needed with dilution of
125 mg/mL
10
20
30
40
50
4.5
9
13.6
18.1
22.7
40 mg
75 mg
115 mg
150 mg
190 mg
0.35 mL
0.6 mL
0.9 mL
1.2 mL
1.5 mL
30 mg
55 mg
85 mg
115 mg
140 mg
0.25 mL
0.45 mL
0.7 mL
0.9 mL
1.1 mL
Weight
50 mg/kg/day
Divided into 3 Doses
50 mg/kg/day
Divided into 4 Doses
Lbs
Kg
Approximate Single Dose mg/q 8 h
Vol. (mL) needed with dilution of
225 mg/mL
Approximate Single Dose mg/q 6 h
Vol. (mL) needed with dilution of
225 mg/mL
10
20
30
40
50
4.5
9
13.6
18.1
22.7
75 mg
150 mg
225 mg
300 mg
375 mg
0.35 mL
0.7 mL
1 mL
1.35 mL
1.7 mL
55 mg
110 mg
170 mg
225 mg
285 mg
0.25 mL
0.5 mL
0.75 mL
1 mL
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.
2.5 Preparation for Use of Cefazolin for Injection
Reconstitution
Preparation of Parenteral Solution
Parenteral drug products should be SHAKEN WELL when reconstituted, and inspected visually for particulate matter prior to administration. If particulate matter is evident in reconstituted fluids, the drug solutions should be discarded.
When reconstituted or diluted according to the instructions below, Cefazolin for Injection is stable for 24 hours at room temperature or for 10 days if stored under refrigeration (5°C or 41°F). Reconstituted solutions may range in color from pale yellow to yellow without a change in potency.
Single-Dose Vials
For IM injection, IV direct (bolus) injection or IV infusion, reconstitute with Sterile Water for Injection according to the following table. SHAKE WELL.
Table 4: Reconstitution Instructions
Vial Size
Amount of Diluent
Approximate
Concentration
Approximate
Available Volume
500 mg
2 mL
225 mg/mL
2.2 mL
1 gram
2.5 mL
330 mg/mL
3 mL
Administration
Intramuscular Administration
Reconstitute vials with Sterile Water for Injection according to the dilution table above. Shake well until dissolved. Cefazolin for Injection should be injected into a large muscle mass. Pain on injection is infrequent with Cefazolin for Injection.
Intravenous Administration
Direct (bolus) injection: Following reconstitution according to the above table, further dilute vials with approximately 5 mL Sterile Water for Injection. Inject the solution slowly over 3 to 5 minutes, directly or through tubing for patients receiving parenteral fluids (see list below).
Intermittent or continuous infusion: Dilute reconstituted Cefazolin for Injection in 50 to 100 mL of one of the following solutions:
Sodium Chloride Injection, USP
5% or 10% Dextrose Injection, USP
5% Dextrose in Lactated Ringer's Injection, USP
5% Dextrose and 0.9% Sodium Chloride Injection, USP
5% Dextrose and 0.45% Sodium Chloride Injection, USP
5% Dextrose and 0.2% Sodium Chloride Injection, USP
Lactated Ringer's Injection, USP
Invert Sugar 5% or 10% in Sterile Water for Injection
Ringer's Injection, USP
5% Sodium Bicarbonate Injection, USP
Prior to administration parenteral drug products should be inspected visually for particulate matter and discoloration whenever solution and container permit.
