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ADD-Vantage ® Vial For Intravenous Administration Rx Only To reduce the development of drug-resistant bacteria and maintain the effectiveness of cefazolin for injection and other antibacterial drugs, cefazolin for injection should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria.

For Intravenous Administration Rx Only To reduce the development of drug-resistant bacteria and maintain the effectiveness of cefazolin for injection and other antibacterial drugs, cefazolin for injection should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria. 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 is stable for 24 hours at room temperature. Reconstituted solutions may range in color from pale yellow to yellow without a change in potency. ADD-Vantage ® Vials ADD-Vantage ® Vials of cefazolin for injection are to be reconstituted only with 0.9% Sodium Chloride Injection or 5% Dextrose Injection in the 50 mL or 100 mL ADD-Vantage ® Flexible Diluent Containers or with 0.45% Sodium Chloride Injection in the 50 mL ADD-Vantage ® Flexible Diluent Container. Cefazolin for injection supplied in single dose ADD-Vantage ® Vials should prepared as directed below. INSTRUCTIONS FOR USE To Open Diluent Container: Peel overwrap at corner and remove solution container. Some opacity of the plastic due to moisture absorption during the sterilization process may be observed. This is normal and does not affect the solution quality or safety. The opacity will diminish gradually. To Assemble Vial and Flexible Diluent Container: (Use Aseptic Technique) 1. Remove the protective covers from the top of the vial and the vial port on the diluent container as follows: a. To remove the breakaway vial cap, swing the pull ring over the top of the vial and pull down far enough to start the opening (see Figure 1 ), then pull straight up to remove the cap (see Figure 2 ). NOTE: Once the breakaway cap has been removed, do not access vial with syringe. b. To remove the vial port cover, grasp the tab on the pull ring, pull up to break the three tie strings, then pull back to remove the cover (see Figure 3 ). 2. Screw the vial into the vial port until it will go no further. THE VIAL MUST BE SCREWED IN TIGHTLY TO ASSURE A SEAL. This occurs approximately 1/2 turn (180°) after the first audible click (see Figure 4 ). The clicking sound does not assure a seal; the vial must be turned as far as it will go. NOTE: Once vial is seated, do not attempt to remove (see Figure 4 ). 3. Recheck the vial to assure that it is tight by trying to turn it further in the direction of assembly. 4. Label appropriately. To Reconstitute the Drug: 1. Squeeze the bottom of the diluent container gently to inflate the portion of the container surrounding the end of the drug vial. 2. With the other hand, push the drug vial down into the container telescoping the walls of the container. Grasp the inner cap of the vial through the walls of the container (see Figure 5 ). 3. Pull the inner cap from the drug vial (see Figure 6 ). Verify that the rubber stopper has been pulled out, allowing the drug and diluent to mix. 4. Mix container contents thoroughly and use within the specified time. Preparation for Administration: (Use Aseptic Technique) 1. Confirm the activation and admixture of vial contents. 2. Check for leaks by squeezing container firmly. If leaks are found, discard unit as sterility may be impaired. 3. Close flow control clamp of administration set. 4. Remove cover from outlet port at bottom of container. 5. Insert piercing pin of administration set into port with a twisting motion until the pin is firmly seated. NOTE: See full directions on administration set carton. 6.

discard unit as sterility may be impaired. 3. Close flow control clamp of administration set. 4. Remove cover from outlet port at bottom of container. 5. Insert piercing pin of administration set into port with a twisting motion until the pin is firmly seated. NOTE: See full directions on administration set carton. 6. Lift the free end of the hanger loop on the bottom of the vial, breaking the two tie strings. Bend the loop outward to lock it in the upright position, then suspend container from hanger. 7. Squeeze and release drip chamber to establish proper fluid level in chamber. 8. Open flow control clamp and clear air from set. Close clamp. 9. Attach set to venipuncture device. If device is not indwelling, prime and make venipuncture. 10. Regulate rate of administration with flow control clamp. WARNING: Do not use flexible container in series connections. instruction-1 instruction-2 instruction-3 instruction-4 Compatibility and Stability Ordinarily ADD-Vantage ® Vials should be reconstituted only when it is certain that the patient is ready to receive the drug. However, Cefazolin for Injection in ADD-Vantage ® vials is stable for 24 hours at room temperature when reconstituted as directed (see RECONSTITUTION, ADD-Vantage® Vials and INSTRUCTIONS FOR USE ). (DO NOT REFRIGERATE OR FREEZE CEFAZOLIN SODIUM IN ADD-VANTAGE ® VIALS.) Prior to administration parenteral drug products should be inspected visually for particulate matter and discoloration whenever solution and container permit.

DESCRIPTION Cefazolin for injection, USP is a semi-synthetic cephalosporin for parenteral administration. It is the sodium salt of (6R,7R)-3-{[(5-methyl-1,3,4-thiadiazol-2-yl)thio] methyl}-8-oxo-7-[2-(1H-tetrazol-1-yl)acetamido]-5-thia-1-azabicyclo [4.2.0] oct-2-ene-2-carboxylic acid. Structural Formula: Molecular Formula: C 14 H 13 N 8 NaO 4 S 3 Molecular Weight: 476.5 The sodium content is 48 mg (2.1 mEq) per 1 gram of cefazolin sodium. Cefazolin for injection, USP is a sterile, white to yellowish powder. Each ADD-Vantage ® vial contains, cefazolin sodium equivalent to 1 gram of cefazolin. chemical-structure

CLINICAL PHARMACOLOGY Studies have shown that following intravenous administration of cefazolin for injection to normal volunteers, mean serum concentrations peaked at approximately 185 mcg/mL and were approximately 4 mcg/mL at 8 hours for a 1-gram dose. The serum half-life for cefazolin is approximately 1.8 hours following intravenous administration. In a study (using normal volunteers) of constant intravenous infusion with dosages of 3.5 mg/kg for one hour (approximately 250 mg) and 1.5 mg/kg the next 2 hours (approximately 100 mg), cefazolin produced a steady serum level at the third hour of approximately 28 mcg/mL. Studies in patients hospitalized with infections indicate that cefazolin produces mean peak serum levels approximately equivalent to those seen in normal volunteers. Bile levels in patients without obstructive biliary disease can reach or exceed serum levels by up to five times; however, in patients with obstructive biliary disease, bile levels of cefazolin are considerably lower than serum levels (<1 mcg/mL). In synovial fluid, the level of cefazolin becomes comparable to that reached in serum at about 4 hours after drug administration. Studies of cord blood show prompt transfer of cefazolin across the placenta. Cefazolin is present in very low concentrations in the milk of nursing mothers. Cefazolin is excreted unchanged in the urine. In the first 6 hours approximately 60% of the drug is excreted in the urine and this increases to 70% to 80% within 24 hours. In patients undergoing peritoneal dialysis (2 L/hour.), cefazolin produced mean serum levels of approximately 10 and 30 mcg/mL after 24 hours’ instillation of a dialyzing solution containing 50 mg/L and 150 mg/L, respectively. Mean peak levels were 29 mcg/mL (range 13 to 44 mcg/mL) with 50 mg/L (3 patients), and 72 mcg/mL (range 26 to 142 mcg/mL) with 150 mg/L (6 patients). Intraperitoneal administration of cefazolin for injection is usually well tolerated. Controlled studies on adult normal volunteers, receiving 1 gram 4 times a day for 10 days, monitoring CBC, SGOT, SGPT, bilirubin, alkaline phosphatase, BUN, creatinine and urinalysis, indicated no clinically significant changes attributed to cefazolin. Microbiology Mechanism of Action Cefazolin is a bactericidal agent that acts by inhibition of bacterial cell wall synthesis. Resistance Predominant mechanisms of bacterial resistance to cephalosporins include the presence of extended-spectrum beta-lactamases and enzymatic hydrolysis. Antimicrobial Activity Cefazolin has been shown to be active against most isolates of the following microorganisms, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE (1) section. Gram-Positive Bacteria Staphylococcus aureus Staphylococcus epidermidis Streptococcus agalactiae Streptococcus pneumoniae Streptococcus pyogenes Methicillin-resistant staphylococci are uniformly resistant to cefazolin. Gram-Negative Bacteria Escherichia coli Proteus mirabilis Most isolates of indole positive Proteus ( Proteus vulgaris ), Enterobacter spp., Morganella morganii , Providencia rettgeri , Serratia spp., and Pseudomonas spp. are resistant to cefazolin. Susceptibility Testing For specific information regarding susceptibility test interpretive criteria and associated test methods and quality control standards recognized by FDA for this drug, please see: https://www.fda.gov/STIC.

Microbiology Mechanism of Action Cefazolin is a bactericidal agent that acts by inhibition of bacterial cell wall synthesis. Resistance Predominant mechanisms of bacterial resistance to cephalosporins include the presence of extended-spectrum beta-lactamases and enzymatic hydrolysis. Antimicrobial Activity Cefazolin has been shown to be active against most isolates of the following microorganisms, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE (1) section. Gram-Positive Bacteria Staphylococcus aureus Staphylococcus epidermidis Streptococcus agalactiae Streptococcus pneumoniae Streptococcus pyogenes Methicillin-resistant staphylococci are uniformly resistant to cefazolin. Gram-Negative Bacteria Escherichia coli Proteus mirabilis Most isolates of indole positive Proteus ( Proteus vulgaris ), Enterobacter spp., Morganella morganii , Providencia rettgeri , Serratia spp., and Pseudomonas spp. are resistant to cefazolin. Susceptibility Testing For specific information regarding susceptibility test interpretive criteria and associated test methods and quality control standards recognized by FDA for this drug, please see: https://www.fda.gov/STIC.

INDICATIONS AND USAGE Cefazolin for injection is indicated in the treatment of the following serious infections due to susceptible organisms: Respiratory Tract Infections: Due to S. pneumoniae, Klebsiella species, H. influenzae, S. aureus (penicillin-sensitive and penicillin-resistant), and group A beta-hemolytic streptococci . Injectable benzathine penicillin is considered to be the drug of choice in treatment and prevention of streptococcal infections, including the prophylaxis of rheumatic fever. Cefazolin for injection is effective in the eradication of streptococci from the nasopharynx; however, data establishing the efficacy of cefazolin in the subsequent prevention of rheumatic fever are not available at present. Urinary Tract Infections: Due to E. coli, P. mirabilis, Klebsiella species, and some strains of enterobacter and enterococci . Skin and Skin Structure Infections: Due to S. aureus (penicillin-sensitive and penicillin-resistant), group A beta-hemolytic streptococci , and other strains of streptococci . Biliary Tract Infections: Due to E. coli, various strains of streptococci , P. mirabilis, Klebsiella species, and S. aureus. Bone and Joint Infections: Due to S. aureus. Genital Infections: (i.e., prostatitis, epididymitis) due to E. coli, P. mirabilis, Klebsiella species, and some strains of enterococci . Septicemia: Due to S. pneumoniae, S. aureus (penicillin-sensitive and penicillin-resistant), P. mirabilis, E. coli, and Klebsiella species. Endocarditis: Due to S. aureus (penicillin-sensitive and penicillin-resistant) and group A beta-hemolytic streptococci . Perioperative Prophylaxis: The prophylactic administration of cefazolin for injection preoperatively, intraoperatively, and postoperatively may reduce the incidence of certain postoperative infections in patients undergoing surgical procedures which are classified as contaminated or potentially contaminated (e.g., vaginal hysterectomy, and cholecystectomy in high-risk patients such as those older than 70 years, with acute cholecystitis, obstructive jaundice, or common duct bile stones). The perioperative use of cefazolin for injection may also be effective in surgical patients in whom infection at the operative site would present a serious risk (e.g., during open-heart surgery and prosthetic arthroplasty). 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 for injection 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 (see DOSAGE AND ADMINISTRATION ). To reduce the development of drug-resistant bacteria and maintain the effectiveness of cefazolin for injection and other antibacterial drugs, cefazolin for injection should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

WARNINGS BEFORE THERAPY WITH CEFAZOLIN FOR INJECTION IS INSTITUTED, CAREFUL INQUIRY SHOULD BE MADE TO DETERMINE WHETHER THE PATIENT HAS HAD PREVIOUS HYPERSENSITIVITY REACTIONS TO CEFAZOLIN, CEPHALOSPORINS, PENICILLINS, OR OTHER DRUGS. IF THIS PRODUCT IS GIVEN TO PENICILLIN-SENSITIVE PATIENTS, CAUTION SHOULD BE EXERCISED BECAUSE CROSS-HYPERSENSITIVITY AMONG BETA-LACTAM ANTIBIOTICS HAS BEEN CLEARLY DOCUMENTED AND MAY OCCUR IN UP TO 10% OF PATIENTS WITH A HISTORY OF PENICILLIN ALLERGY. IF AN ALLERGIC REACTION TO CEFAZOLIN FOR INJECTION OCCURS, DISCONTINUE TREATMENT WITH THE DRUG. SERIOUS ACUTE HYPERSENSITIVITY REACTIONS MAY REQUIRE TREATMENT WITH EPINEPHRINE AND OTHER EMERGENCY MEASURES, INCLUDING OXYGEN, IV FLUIDS, IV ANTIHISTAMINES, CORTICOSTEROIDS, PRESSOR AMINES, AND AIRWAY MANAGEMENT, AS CLINICALLY INDICATED. Pseudomembranous colitis has been reported with nearly all antibacterial agents, including cefazolin, and may range in severity from mild to life-threatening. Therefore, it is important to consider this diagnosis in patients who present with diarrhea subsequent to the administration of antibacterial agents. Treatment with antibacterial agents alters the normal flora of the colon and may permit overgrowth of clostridia. Studies indicate that a toxin produced by Clostridium difficile is a primary cause of “antibiotic-associated colitis.” After the diagnosis of pseudomembranous colitis has been established, therapeutic measures should be initiated. Mild cases of pseudomembranous colitis usually respond to drug discontinuation alone. In moderate to severe cases, consideration should be given to management with fluids and electrolytes, protein supplementation, and treatment with an oral antibacterial drug clinically effective against C. difficile colitis.

PRECAUTIONS General Prolonged use of cefazolin may result in the overgrowth of nonsusceptible organisms. Careful clinical observation of the patient is essential. When cefazolin is administered to patients with low urinary output because of impaired renal function, lower daily dosage is required (see DOSAGE AND ADMINISTRATION ). As with other beta-lactam antibiotics, seizures may occur if inappropriately high doses are administered to patients with impaired renal function (see DOSAGE AND ADMINISTRATION ). Cefazolin as with all cephalosporins, should be prescribed with caution in individuals with a history of gastrointestinal disease, particularly colitis. Cephalosporins may be associated with a fall in prothrombin activity. Those at risk include patients with renal or hepatic impairment or poor nutritional state, as well as patients receiving a protracted course of antimicrobial therapy, and patients previously stabilized on anticoagulant therapy. Prothrombin time should be monitored in patients at risk and exogenous vitamin K administered as indicated. Prescribing cefazolin in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria. Drug Interactions Probenecid may decrease renal tubular secretion of cephalosporins when used concurrently, resulting in increased and more prolonged cephalosporin blood levels. Drug/Laboratory Test Interactions A false positive reaction for glucose in the urine may occur with Benedict’s solution, Fehling’s solution or with CLINITEST ® tablets, but not with enzyme-based tests such as CLINISTIX ® . Positive direct and indirect antiglobulin (Coombs) tests have occurred; these may also occur in neonates whose mothers received cephalosporins before delivery. Information for Patients Patients should be counseled that antibacterial drugs including cefazolin, should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When cefazolin is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may: (1) decrease the effectiveness of the immediate treatment, and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by cefazolin or other antibacterial drugs in the future. Carcinogenesis/Mutagenesis Mutagenicity studies and long-term studies in animals to determine the carcinogenic potential of cefazolin have not been performed. Pregnancy Teratogenic Effects Reproduction studies have been performed in rats, mice, and rabbits at doses up to 25 times the human dose and have revealed no evidence of impaired fertility or harm to the fetus due to cefazolin. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed. Labor and Delivery When cefazolin has been administered prior to caesarean section, drug levels in cord blood have been approximately one quarter to one third of maternal drug levels. The drug appears to have no adverse effect on the fetus.

man response, this drug should be used during pregnancy only if clearly needed. Labor and Delivery When cefazolin has been administered prior to caesarean section, drug levels in cord blood have been approximately one quarter to one third of maternal drug levels. The drug appears to have no adverse effect on the fetus. Nursing Mothers Cefazolin is present in very low concentrations in the milk of nursing mothers. Caution should be exercised when cefazolin is administered to a nursing woman. Pediatric Use Safety and effectiveness for use in premature infants and neonates have not been established. See DOSAGE AND ADMINISTRATION for recommended dosage in pediatric patients older than 1 month. Geriatric Use Of the 920 subjects who received cefazolin in clinical studies, 313 (34%) were 65 years and over, while 138 (15%) were 75 years and over. No overall differences in safety or effectiveness were observed between these subjects and younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out. This drug is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function (see PRECAUTIONS, General and DOSAGE AND ADMINISTRATION ).

General Prolonged use of cefazolin may result in the overgrowth of nonsusceptible organisms. Careful clinical observation of the patient is essential. When cefazolin is administered to patients with low urinary output because of impaired renal function, lower daily dosage is required (see DOSAGE AND ADMINISTRATION ). As with other beta-lactam antibiotics, seizures may occur if inappropriately high doses are administered to patients with impaired renal function (see DOSAGE AND ADMINISTRATION ). Cefazolin as with all cephalosporins, should be prescribed with caution in individuals with a history of gastrointestinal disease, particularly colitis. Cephalosporins may be associated with a fall in prothrombin activity. Those at risk include patients with renal or hepatic impairment or poor nutritional state, as well as patients receiving a protracted course of antimicrobial therapy, and patients previously stabilized on anticoagulant therapy. Prothrombin time should be monitored in patients at risk and exogenous vitamin K administered as indicated. Prescribing cefazolin in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.

Drug/Laboratory Test Interactions A false positive reaction for glucose in the urine may occur with Benedict’s solution, Fehling’s solution or with CLINITEST ® tablets, but not with enzyme-based tests such as CLINISTIX ® . Positive direct and indirect antiglobulin (Coombs) tests have occurred; these may also occur in neonates whose mothers received cephalosporins before delivery.

Information for Patients Patients should be counseled that antibacterial drugs including cefazolin, should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When cefazolin is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may: (1) decrease the effectiveness of the immediate treatment, and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by cefazolin or other antibacterial drugs in the future.

Pregnancy Teratogenic Effects Reproduction studies have been performed in rats, mice, and rabbits at doses up to 25 times the human dose and have revealed no evidence of impaired fertility or harm to the fetus due to cefazolin. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Teratogenic Effects Reproduction studies have been performed in rats, mice, and rabbits at doses up to 25 times the human dose and have revealed no evidence of impaired fertility or harm to the fetus due to cefazolin. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Labor and Delivery When cefazolin has been administered prior to caesarean section, drug levels in cord blood have been approximately one quarter to one third of maternal drug levels. The drug appears to have no adverse effect on the fetus.

Pediatric Use Safety and effectiveness for use in premature infants and neonates have not been established. See DOSAGE AND ADMINISTRATION for recommended dosage in pediatric patients older than 1 month.

Geriatric Use Of the 920 subjects who received cefazolin in clinical studies, 313 (34%) were 65 years and over, while 138 (15%) were 75 years and over. No overall differences in safety or effectiveness were observed between these subjects and younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out. This drug is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function (see PRECAUTIONS, General and DOSAGE AND ADMINISTRATION ).

ADVERSE REACTIONS The following reactions have been reported: Gastrointestinal: Diarrhea, oral candidiasis (oral thrush), vomiting, nausea, stomach cramps, anorexia, and pseudomembranous colitis. Onset of pseudomembranous colitis symptoms may occur during or after antibiotic treatment (see WARNINGS ). Nausea and vomiting have been reported rarely. Allergic: Anaphylaxis, eosinophilia, itching, drug fever, skin rash, Stevens-Johnson syndrome. Hematologic: Neutropenia, leukopenia, thrombocytopenia, thrombocythemia. Hepatic: Transient rise in SGOT, SGPT, and alkaline phosphatase levels has been observed. As with other cephalosporins, reports of hepatitis have been received. Renal: As with other cephalosporins, reports of increased BUN and creatinine levels, as well as renal failure, have been received. Local Reactions: Rare instances of phlebitis have been reported at site of injection. Other Reactions: Genital and anal pruritus (including vulvar pruritus, genital moniliasis, and vaginitis). To report SUSPECTED ADVERSE REACTIONS, contact Hospira, Inc. at 1-800-441-4100 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

DOSAGE AND ADMINISTRATION Note: Cefazolin for Injection in the ADD-Vantage® Vial is intended for intravenous infusion. Usual Adult Dosage 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) In rare instances, doses of up to 12 grams of cefazolin for injection per day have been used. 1 gram to 1.5 grams every 6 hours Perioperative Prophylactic Use To prevent postoperative infection in contaminated or potentially contaminated surgery, recommended doses are: a. 1 gram intravenous 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 intravenous during surgery (administration modified depending on the duration of the operative procedure). c. 500 mg to 1 gram intravenous 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 for injection 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. In surgery where the occurrence of infection may be particularly devastating (e.g., open-heart surgery and prosthetic arthroplasty), the prophylactic administration of cefazolin for injection may be continued for 3 to 5 days following the completion of surgery. Dosage Adjustment for Patients with Reduced Renal Function Cefazolin for injection may be used in patients with reduced renal function with the following dosage adjustments: Patients with a creatinine clearance of 55 mL/min. or greater or a serum creatinine of 1.5 mg% or less can be given full doses. Patients with creatinine clearance rates of 35 to 54 mL/min. or serum creatinine of 1.6 to 3 mg% can also be given full doses but dosage should be restricted to at least 8 hour intervals. Patients with creatinine clearance rates of 11 to 34 mL/min. or serum creatinine of 3.1 to 4.5 mg% should be given 1/2 the usual dose every 12 hours. Patients with creatinine clearance rates of 10 mL/min. or less or serum creatinine of 4.6 mg% or greater should be given 1/2 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 CLINICAL PHARMACOLOGY . 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. 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/every 8 hours Vol.

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. 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/every 8 hours Vol. (mL) needed with dilution of 125 mg/mL Approximate Single Dose mg/every 6 hours Vol. (mL) needed with dilution of 125 mg/mL 10 4.5 40 mg 0.35 mL 30 mg 0.25 mL 20 9 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 Divided into 3 Doses 50 mg/kg/day Divided into 4 Doses Lbs Kg Approximate Single Dose mg/every 8 hours Vol. (mL) needed with dilution of 225 mg/mL Approximate Single Dose mg/every 6 hours Vol. (mL) needed with dilution of 225 mg/mL 10 4.5 75 mg 0.35 mL 55 mg 0.25 mL 20 9 150 mg 0.70 mL 110 mg 0.50 mL 30 13.6 225 mg 1 mL 170 mg 0.75 mL 40 18.1 300 mg 1.35 mL 225 mg 1 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.

HOW SUPPLIED Each Cefazolin for Injection, USP ADD-Vantage ® vial contains, cefazolin sodium equivalent to 1 gram of cefazolin. It is supplied in packages of 25 (NDC 0409-2585-01). As with other cephalosporins, Cefazolin for Injection, USP tends to darken depending on storage conditions; within the stated recommendations, however, product potency is not adversely affected. Before reconstitution, protect from light and store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. CLINITEST ® is a registered trademark of Miles, Inc. CLINISTIX ® is a registered trademark of Bayer Corporation. Revised: September 2020 46276359 Manufactured by Sandoz GmbH for Hospira, Inc., Lake Forest, IL 60045, USA

Rx only To reduce the development of drug-resistant bacteria and maintain the effectiveness of Cefazolin for Injection and other antibacterial drugs, Cefazolin for Injection should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria. CLINITEST is a registered trademark of Miles, Inc. CLINISTIX is a registered trademark of Bayer Corporation. Manufactured by: HIKMA FARMACÊUTICA (PORTUGAL) S.A. Estrada do Rio da Mó, 8, 8A e 8B – Fervença 2705-906 Terrugem SNT PORTUGAL Distributed by: Hikma Pharmaceuticals USA Inc. Berkeley Heights, NJ 07922 Revised: June 2020 PIN001-WES/8

DESCRIPTION Cefazolin for Injection, USP is a semi-synthetic cephalosporin for parenteral administration. It is the sodium salt of 3-{[(5-methyl-1,3,4-­thiadiazol-2-yl)thio]-methyl}-8-oxo-7-[2-(1H-tetrazol-1-yl) acetamido]-5-thia-1-azabicyclo [4.2.0]oct-2-ene-2-carboxylic acid. The molecular formula is C 14 H 13 N 8 NaO 4 S 3 and molecular weight is 476.49. Structural Formula: Each vial contains 48 mg of sodium/1 gram of cefazolin sodium. Cefazolin for Injection, USP is white to off-white crystalline powder, supplied in vials equivalent to 500 mg or 1 gram of cefazolin. Formula1.jpg

CLINICAL PHARMACOLOGY After intramuscular administration of Cefazolin for Injection to normal volunteers, the mean serum concentrations were 37 mcg/mL at 1 hour and 3 mcg/mL at 8 hours following a 500 mg dose, and 64 mcg/mL at 1 hour and 7 mcg/mL at 8 hours following a 1 gram dose. Studies have shown that following intravenous administration of Cefazolin for Injection to normal volunteers, mean serum concentrations peaked at approximately 185 mcg/mL and were approximately 4 mcg/mL at 8 hours for a 1 gram dose. The serum half-life for Cefazolin for Injection is approximately 1.8 hours following IV administration and approximately 2 hours following IM administration. In a study (using normal volunteers) of constant intravenous infusion with dosages of 3.5 mg/kg for 1 hour (approximately 250 mg) and 1.5 mg/kg the next 2 hours (approximately 100 mg), Cefazolin for Injection produced a steady serum level at the third hour of approximately 28 mcg/mL. Studies in patients hospitalized with infections indicate that Cefazolin for Injection produces mean peak serum levels approximately equivalent to those seen in normal volunteers. Bile levels in patients without obstructive biliary disease can reach or exceed serum levels by up to five times; however, in patients with obstructive biliary disease, bile levels of Cefazolin for Injection are considerably lower than serum levels (< 1 mcg/mL). In synovial fluid, the level of Cefazolin for Injection becomes comparable to that reached in serum at about 4 hours after drug administration. Studies of cord blood show prompt transfer of Cefazolin for Injection across the placenta. Cefazolin for Injection is present in very low concentrations in the milk of nursing mothers. Cefazolin for Injection is excreted unchanged in the urine. In the first 6 hours approximately 60% of the drug is excreted in the urine and this increases to 70% to 80% within 24 hours. Cefazolin for Injection achieves peak urine concentrations of approximately 2,400 mcg/mL and 4,000 mcg/mL respectively following 500 mg and 1 gram intramuscular doses. In patients undergoing peritoneal dialysis (2 L/hr.), Cefazolin for Injection produced mean serum levels of approximately 10 and 30 mcg/mL after 24 hours’ instillation of a dialyzing solution containing 50 mg/L and 150 mg/L, respectively. Mean peak levels were 29 mcg/mL (range 13 to 44 mcg/mL) with 50 mg/L (3 patients), and 72 mcg/mL (range 26 to 142 mcg/mL) with 150 mg/L (6 patients). Intraperitoneal administration of Cefazolin for Injection is usually well tolerated. Controlled studies on adult normal volunteers, receiving 1 gram 4 times a day for 10 days, monitoring CBC, SGOT, SGPT, bilirubin, alkaline phosphatase, BUN, creatinine and urinalysis, indicated no clinically significant changes attributed to Cefazolin for Injection. Microbiology Mechanism of Action Cefazolin is a bactericidal agent that acts by inhibition of bacterial cell wall synthesis. Resistance Predominant mechanisms of bacterial resistance to cephalosporins include the presence of extended-spectrum beta-lactamases and enzymatic hydrolysis.

ributed to Cefazolin for Injection. Microbiology Mechanism of Action Cefazolin is a bactericidal agent that acts by inhibition of bacterial cell wall synthesis. Resistance Predominant mechanisms of bacterial resistance to cephalosporins include the presence of extended-spectrum beta-lactamases and enzymatic hydrolysis. Antimicrobial Activity Cefazolin has been shown to be active against most isolates of the following microorganisms, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE (1) section: Gram-Positive Bacteria: Staphylococcus aureus Staphylococcus epidermidis Streptococcus agalactiae Streptococcus pneumoniae Streptococcus pyogenes Methicillin-resistant staphylococci are uniformly resistant to cefazolin. Gram-Negative Bacteria: Escherichia coli Proteus mirabilis Most isolates of indole positive Proteus ( Proteus vulgaris ), Enterobacter spp., Morganella morganii , Providencia rettgeri , Serratia spp., and Pseudomonas spp. are resistant to cefazolin. Susceptibility Test Methods For specific information regarding susceptibility test interpretive criteria and associated test methods and quality control standards recognized by FDA for this drug, please see: HTTPS://WWW.FDA.GOV/STIC.

INDICATIONS AND USAGE Cefazolin for Injection, USP is indicated in the treatment of the following serious infections due to susceptible organisms: Respiratory Tract Infections : Due to S. pneumoniae , Klebsiella species, H. influenzae , S. aureus (penicillin-sensitive and penicillin-resistant), and group A beta-hemolytic streptococci. Injectable benzathine penicillin is considered to be the drug of choice in treatment and prevention of streptococcal infections, including the prophylaxis of rheumatic fever. Cefazolin for Injection is effective in the eradication of streptococci from the nasopharynx; however, data establishing the efficacy of Cefazolin for Injection in the subsequent prevention of rheumatic fever are not available at present. Urinary Tract Infections : Due to E. coli, P. mirabilis, Klebsiella species, and some strains of enterobacter and enterococci. Skin and Skin Structure Infections : Due to S. aureus (penicillin-sensitive and penicillin-resistant), group A beta-hemolytic streptococci, and other strains of streptococci. Biliary Tract Infections : Due to E. coli , various strains of streptococci, P. mirabilis, Klebsiella species, and S. aureus . Bone and Joint Infections : Due to S. aureus . Genital Infections : (i.e., prostatitis, epididymitis) due to E. coli, P. mirabilis, Klebsiella species, and some strains of enterococci. Septicemia : Due to S. pneumoniae, S. aureus (penicillin-sensitive and penicillin-resistant), P. mirabilis, E. coli and Klebsiella species. Endocarditis : Due to S. aureus (penicillin-sensitive and penicillin-resistant) and group A beta-hemolytic streptococci. Perioperative Prophylaxis : The prophylactic administration of Cefazolin for Injection preoperatively, intraoperatively and postoperatively may reduce the incidence of certain postoperative infections in patients undergoing surgical procedures which are classified as contaminated or potentially contaminated (e.g., vaginal hysterectomy, and cholecystectomy in high-risk patients such as those older than 70 years, with acute cholecystitis, obstructive jaundice, or common duct bile stones). The perioperative use of Cefazolin for Injection may also be effective in surgical patients in whom infection at the operative site would present a serious risk (e.g., during open-heart surgery and prosthetic arthroplasty). 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 for Injection 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 (see DOSAGE AND ADMINISTRATION ). To reduce the development of drug-resistant bacteria and maintain the effectiveness of Cefazolin for Injection, USP and other antibacterial drugs, Cefazolin for Injection, USP should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy.

and other antibacterial drugs, Cefazolin for Injection, USP should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

WARNINGS BEFORE THERAPY WITH CEFAZOLIN FOR INJECTION IS INSTITUTED, CAREFUL INQUIRY SHOULD BE MADE TO DETERMINE WHETHER THE PATIENT HAS HAD PREVIOUS HYPERSENSITIVITY REACTIONS TO CEFAZOLIN, CEPHALOSPORINS, PENICILLINS, OR OTHER DRUGS. IF THIS PRODUCT IS GIVEN TO PENICILLIN-SENSITIVE PATIENTS, CAUTION SHOULD BE EXERCISED BECAUSE CROSS-HYPERSENSITIVITY AMONG BETA-LACTAM ANTIBIOTICS HAS BEEN CLEARLY DOCUMENTED AND MAY OCCUR IN UP TO 10% OF PATIENTS WITH A HISTORY OF PENICILLIN ALLERGY. IF AN ALLERGIC REACTION TO CEFAZOLIN FOR INJECTION OCCURS, DISCONTINUE TREATMENT WITH THE DRUG. SERIOUS ACUTE HYPERSENSITIVITY REACTIONS MAY REQUIRE TREATMENT WITH EPINEPHRINE AND OTHER EMERGENCY MEASURES, INCLUDING OXYGEN, IV FLUIDS, IV ANTIHISTAMINES, CORTICOSTEROIDS, PRESSOR AMINES, AND AIRWAY MANAGEMENT, AS CLINICALLY INDICATED. Pseudomembranous colitis has been reported with nearly all antibacterial agents, including cefazolin, and may range in severity from mild to life-threatening. Therefore, it is important to consider this diagnosis in patients who present with diarrhea subsequent to the administration of antibacterial agents. Treatment with antibacterial agents alters the normal flora of the colon and may permit overgrowth of clostridia. Studies indicate that a toxin produced by Clostridium difficile is a primary cause of “antibiotic-associated colitis”. After the diagnosis of pseudomembranous colitis has been established, therapeutic measures should be initiated. Mild cases of pseudomembranous colitis usually respond to drug discontinuation alone. In moderate to severe cases, consideration should be given to management with fluids and electrolytes, protein supplementation, and treatment with an oral antibacterial drug clinically effective against C. difficile colitis.

PRECAUTIONS General Prolonged use of Cefazolin for Injection may result in the overgrowth of nonsusceptible organisms. Careful clinical observation of the patient is essential. When Cefazolin for Injection is administered to patients with low urinary output because of impaired renal function, lower daily dosage is required (see DOSAGE AND ADMINISTRATION ). As with other β-lactam antibiotics, seizures may occur if inappropriately high doses are administered to patients with impaired renal function (see DOSAGE AND ADMINISTRATION ). Cefazolin for Injection, as with all cephalosporins, should be prescribed with caution in individuals with a history of gastrointestinal disease, particularly colitis. Cephalosporins may be associated with a fall in prothrombin activity. Those at risk include patients with renal or hepatic impairment or poor nutritional state, as well as patients receiving a protracted course of antimicrobial therapy, and patients previously stabilized on anticoagulant therapy. Prothrombin time should be monitored in patients at risk and exogenous vitamin K administered as indicated. Prescribing Cefazolin for Injection in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria. Drug Interactions Probenecid may decrease renal tubular secretion of cephalosporins when used concurrently, resulting in increased and more prolonged cephalosporin blood levels. Drug/Laboratory Test Interactions A false positive reaction for glucose in the urine may occur with Benedict's solution, Fehling’s solution or with CLINITEST® tablets, but not with enzyme-based tests such as CLINISTIX®. Positive direct and indirect antiglobulin (Coombs) tests have occurred; these may also occur in neonates whose mothers received cephalosporins before delivery. Information for Patients Patients should be counseled that antibacterial drugs including Cefazolin for Injection, should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When Cefazolin for Injection is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may: (1) decrease the effectiveness of the immediate treatment, and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by Cefazolin for Injection or other antibacterial drugs in the future. Carcinogenesis/Mutagenesis Mutagenicity studies and long-term studies in animals to determine the carcinogenic potential of Cefazolin for Injection have not been performed. Pregnancy Teratogenic Effects Pregnancy Category B Reproduction studies have been performed in rats, mice and rabbits at doses up to 25 times the human dose and have revealed no evidence of impaired fertility or harm to the fetus due to Cefazolin for Injection. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

evealed no evidence of impaired fertility or harm to the fetus due to Cefazolin for Injection. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed. Labor and Delivery When cefazolin has been administered prior to caesarean section, drug levels in cord blood have been approximately one quarter to one third of maternal drug levels. The drug appears to have no adverse effect on the fetus. Nursing Mothers Cefazolin for Injection is present in very low concentrations in the milk of nursing mothers. Caution should be exercised when Cefazolin for Injection is administered to a nursing woman. Pediatric Use Safety and effectiveness for use in premature infants and neonates have not been established. See DOSAGE AND ADMINISTRATION for recommended dosage in pediatric patients older than 1 month. Geriatric Use Of the 920 subjects who received Cefazolin for Injection in clinical studies, 313 (34%) were 65 years and over, while 138 (15%) were 75 years and over. No overall differences in safety or effectiveness were observed between these subjects and younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out. This drug is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function (see PRECAUTIONS, General and DOSAGE AND ADMINISTRATION ).

ADVERSE REACTIONS The following reactions have been reported: Gastrointestinal Diarrhea, oral candidiasis (oral thrush), vomiting, nausea, stomach cramps, anorexia, and pseudomembranous colitis. Onset of pseudomembranous colitis symptoms may occur during or after antibiotic treatment (see WARNINGS ). Nausea and vomiting have been reported rarely. Allergic Anaphylaxis, eosinophilia, itching, drug fever, skin rash, Stevens-Johnson syndrome. Hematologic Neutropenia, leukopenia, thrombocytopenia, thrombocythemia. Hepatic Transient rise in SGOT, SGPT, and alkaline phosphatase levels has been observed. As with other cephalosporins, reports of hepatitis have been received. Renal As with other cephalosporins, reports of increased BUN and creatinine levels, as well as renal failure, have been received. Local Reactions Rare instances of phlebitis have been reported at site of injection. Pain at the site of injection after intramuscular administration has occurred infrequently. Some induration has occurred. Other Reactions Genital and anal pruritus (including vulvar pruritus, genital moniliasis, and vaginitis). To report SUSPECTED ADVERSE REACTIONS, contact West-Ward Pharmaceuticals Corp. at 1-877-233-2001, or the FDA at 1-800-FDA-1088 or WWW.FDA.GOV/MEDWATCH.

DOSAGE AND ADMINISTRATION Usual Adult Dosage 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 for Injection 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. In surgery where the occurrence of infection may be particularly devastating (e.g., open-heart surgery and prosthetic arthroplasty), the prophylactic administration of Cefazolin for Injection may be continued for 3 to 5 days following the completion of surgery. Dosage Adjustment for Patients with Reduced Renal Function Cefazolin for Injection may be used in patients with reduced renal function with the following dosage adjustments: Patients with a creatinine clearance of 55 mL/min. or greater or a serum creatinine of 1.5 mg % or less can be given full doses. Patients with creatinine clearance rates of 35 to 54 mL/min. or serum creatinine of 1.6 to 3 mg % can also be given full doses but dosage should be restricted to at least 8 hour intervals. Patients with creatinine clearance rates of 11 to 34 mL/min. or serum creatinine of 3.1 to 4.5 mg % should be given 1/2 the usual dose every 12 hours. Patients with creatinine clearance rates of 10 mL/min. or less or serum creatinine of 4.6 mg % or greater should be given 1/2 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 CLINICAL PHARMACOLOGY . 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. 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.

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. 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. 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 1 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 Image1.jpg Image2.jpg Image3.jpg

How Supplied Cefazolin for Injection, USP is supplied in vials containing cefazolin sodium equivalent to 500 mg or 1 gram cefazolin. Also available as Pharmacy Bulk Package, as follows: As with other cephalosporins, Cefazolin for Injection, USP tends to darken depending on storage conditions; within the stated recommendations, however, product potency is not adversely affected. Before reconstitution protect from light and store at 20° to 25°C (68° to 77°F) [See USP Controlled Room Temperature]. Product repackaged by: Henry Schein, Inc., Bastian, VA 24314 From Original Manufacturer/Distributor's NDC and Unit of Sale To Henry Schein Repackaged Product NDC and Unit of Sale Total Strength/Total Volume (Concentration) per unit NDC 0143-9923-90 Carton of 25 vials NDC 0404-9835-99 1 10 mL vial in a bag (Vial bears NDC 0143-9923-90) 500 mg NDC 0143-9924-90 Carton of 25 vials NDC 0404-9834-99 1 10 mL vial in a bag (Vial bears NDC 0143-9924-90) 1 gram Image4.jpg Image5.jpg

<table width="100%"><caption>Product repackaged by: Henry Schein, Inc., Bastian, VA 24314 </caption><tbody><tr><td>From Original Manufacturer/Distributor&apos;s NDC and Unit of Sale</td><td>To Henry Schein Repackaged Product NDC and Unit of Sale</td><td>Total Strength/Total Volume (Concentration) per unit</td></tr><tr><td>NDC 0143-9923-90 Carton of 25 vials</td><td>NDC 0404-9835-99 1 10 mL vial in a bag (Vial bears NDC 0143-9923-90)</td><td>500 mg</td></tr><tr><td>NDC 0143-9924-90 Carton of 25 vials</td><td>NDC 0404-9834-99 1 10 mL vial in a bag (Vial bears NDC 0143-9924-90)</td><td>1 gram</td></tr></tbody></table>

1 INDICATIONS AND USAGE Cefazolin for Injection is a cephalosporin antibacterial indicated for perioperative prophylaxis in adult patients (1.1). To reduce the development of drug-resistant bacteria and maintain the effectiveness of Cefazolin for Injection and other antibacterial drugs, Cefazolin for Injection should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria (1.2). 1.1 Perioperative Prophylaxis Cefazolin for Injection is indicated for perioperative prophylaxis in adult patients [see Dosage and Administration (2.1, 2.2, 2.3) . The perioperative use of Cefazolin for Injection is indicated in adult surgical patients in whom infection at the operative site would present a serious risk (e.g., during open-heart surgery and prosthetic arthroplasty). The prophylactic administration of Cefazolin for Injection preoperatively, intraoperatively and postoperatively may reduce the incidence of certain postoperative infections in patients undergoing surgical procedures which are classified as contaminated or potentially contaminated (e.g., vaginal hysterectomy, and cholecystectomy in high-risk patients such as those older than 70 years, with acute cholecystitis, obstructive jaundice or common duct bile stones). 1.2 Usage To reduce the development of drug-resistant bacteria and maintain the effectiveness of Cefazolin for Injection and other antibacterial drugs, Cefazolin for Injection should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

2 DOSAGE AND ADMINISTRATION Cefazolin for Injection, 2 grams/vial: • For intravenous infusion (2.1) • For intravenous bolus injection (2.1) • Not for intramuscular administration (2.1) Cefazolin for Injection, 3 grams/vial: • For intravenous infusion only (2.1) • Not for intravenous bolus injection administration or intramuscular administration (2.1) Table 1: Recommended Dosage for Perioperative Prophylaxis in Adults with CLcr Equal to 55 mL/min or Greater (2.2) Dose administered ½ hour to 1 hour prior to the start of surgery Additional dose during lengthy operative procedures (e.g., 2 hours or more) Dose for 24 hours postoperatively 1 gram (g) to 2 g 500 mg to 1 g 500 mg to 1 g every 6 hours to 8 hours • See full prescribing information for preparation and administration instructions. (2.3) 2.1 Important Administration Instructions • Cefazolin for Injection, 2 grams/vial: Cefazolin for Injection, 2 grams/vial, is for intravenous infusion or intravenous bolus injection in adult patients [see Dosage and Administration (2.2 and 2.3)]. Not for intramuscular administration. • Cefazolin for Injection, 3 grams/vial: Cefazolin for Injection, 3 grams/vial, is for intravenous infusion only in adult patients [see Dosage and Administration (2.2 and 2.3)] . Cefazolin for Injection, 3 grams/vial is not for intravenous bolus injection or intramuscular administration [see Dosage and Administration (2.3)] . 2.2 Recommended Dosage for Perioperative Prophylaxis Use in Adults Recommended Dosage for Perioperative Prophylaxis in Adults with Creatinine Clearance (CLcr) Equal to 55 mL/min or Greater To prevent postoperative infection in contaminated or potentially contaminated surgery, recommended dosages are described in Table 1 below. Administration instructions are as follows: • Cefazolin for Injection, 2 grams/vial is for intravenous infusion or intravenous bolus injection in adult patients [see Dosage and Administration (2.3)] . • Cefazolin for Injection, 3 grams/vial is only for intravenous infusion in adult patients. • Cefazolin for Injection, 3 grams/vial is not for intravenous bolus injection in adult patients [see Dosage and Administration (2.3)] . • Cefazolin for Injection 2 grams/vial and 3 grams/vial are not for intramuscular injection. Table 1: Recommended Dosage for Perioperative Prophylaxis in Adults with CLcr Equal to 55 mL/min or Greater Dose administered ½ hour to 1 hour prior to the start of surgery Additional dose during lengthy operative procedures (e.g., 2 hours or more) Dose for 24 hours postoperatively 1 gram (g) to 2 g 500 mg to 1 g 500 mg to 1 g every 6 hours to 8 hours 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 perioperative prophylactic administration of Cefazolin for Injection should usually be discontinued within a 24-hour period after the surgical procedure.

te intervals during surgery to provide sufficient concentrations of the antibacterial drug at the anticipated moments of greatest exposure to infective organisms. The perioperative 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 for Injection may be continued for 3 to 5 days following the completion of surgery. 2.3 Preparation of Cefazolin for Injection Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. If particulate matter is evident in reconstituted fluids, the drug solutions should be discarded. Reconstituted solutions may range in color from pale yellow to yellow. Reconstitution and Dilution Intravenous Bolus Injection Administration (2 g vial only) For preparation of intravenous bolus injection (2 grams/vial only) use the following steps: • Reconstitute Cefazolin for Injection, 2 grams/vial single-dose vials with Sterile Water for Injection according to Table 2 below. Shake well until dissolved. • Further dilute vials with an additional 11 mL Sterile Water for Injection and shake well. • Inject the solution intravenously slowly, directly, or through tubing for patients receiving parenteral fluids as follows: a For 1 g dose, inject the solution intravenously slowly over 3 to 5 minutes and b For 2 g dose, inject the solution intravenously slowly over 7 to 11 minutes Table 2: Volume and Concentration for Intravenous Bolus Injection Reconstitution (2 g vial only) Cefazolin for Injection Vial Contents Amount of Sterile Water for Injection for Reconstitution Approximate Reconstituted Concentration Approximate Available Volume 2 grams 5.5 mL 333 mg/mL 6.6 mL Pain associated with intravenous bolus administration has been reported with Cefazolin for Injection. Intermittent or Continuous Intravenous Infusion For intermittent or continuous intravenous infusion, reconstitute Cefazolin for Injection single-dose vials with Sterile Water for Injection according to Table 3 below and shake well . After reconstitution further dilute according to Table 3 using the following diluents: For intermittent or continuous infusion: Dilute reconstituted Cefazolin for Injection in one of the following solutions: • 0.9% Sodium Chloride Injection, USP • 5% Dextrose Injection, USP Discard unused portion. Table 3: Volumes for Reconstitution and Dilution and Final Concentrations for Intermittent or Continuous Intravenous Infusion Cefazolin for Injection Vial Contents Amount of Sterile Water for Injection for Reconstitution Approximate Reconstituted Concentrations Recommended Diluent Volume Approximate Final Concentrations 2 grams 5 mL 317 mg/mL 50 mL 40 mg/mL 100 mL 20 mg/mL 3 grams 7.5 mL 319 mg/mL 100 mL 30 mg/mL Storage of Reconstituted and Diluted Solutions When reconstituted or diluted according to the instructions above, Cefazolin for Injection is stable for 4 hours at room temperature or for 3 days if stored under refrigeration at 2°C to 8°C (36°F to 46°F).

3 DOSAGE FORMS AND STRENGTHS Cefazolin for Injection, USP: Supplied as 2 grams or 3 grams of cefazolin as a white to cream colored powder in a single-dose vial for reconstitution. For Injection: 2 grams or 3 grams of cefazolin as a powder in a single-dose vial for reconstitution. (3)

4 CONTRAINDICATIONS Hypersensitivity to cefazolin or other cephalosporin class antibacterial drugs, penicillins, or other beta-lactams (4.1) 4.1 Hypersensitivity to Cefazolin or the Cephalosporin Class of Antibacterial Drugs, Penicillins, or Other Beta-lactams Cefazolin for Injection is contraindicated in patients who have a history of immediate hypersensitivity reactions (e.g., anaphylaxis, serious skin reactions) to cefazolin or the cephalosporin class of antibacterial drugs, penicillins, or other beta-lactams [see Warnings and Precautions (5.1)] .

5 WARNINGS AND PRECAUTIONS • Hypersensitivity Reactions: Cross-hypersensitivity may occur in up to 10% of patients with a history of penicillin allergy. If an allergic reaction occurs, discontinue the drug. (5.1) • Clostridioides difficile -Associated Diarrhea (CDAD) : May range from mild diarrhea to fatal colitis. Evaluate if diarrhea occurs. (5.3) • Prothrombin Activity : May be associated with a fall in prothrombin activity. Prothrombin time should be monitored in patients at risk and exogenous vitamin K administered as indicated (5.5) 5.1 Hypersensitivity Reactions to Cefazolin, Cephalosporins, Penicillins, or Other Beta-lactams Serious and occasionally fatal hypersensitivity (anaphylactic) reactions have been reported in patients receiving beta-lactam antibacterial drugs. Before therapy with Cefazolin for Injection is instituted, careful inquiry should be made to determine whether the patient has had previous immediate hypersensitivity reactions to cefazolin, cephalosporins, penicillins, or carbapenems. Exercise caution if this product is to be given to penicillin-sensitive patients because cross-hypersensitivity among beta-lactam antibacterial drugs has been clearly documented and may occur in up to 10% of patients with a history of penicillin allergy. If an allergic reaction to Cefazolin for Injection occurs, discontinue the drug. 5.2 Seizures in Patients with Renal Impairment Seizures may occur with the administration of Cefazolin for Injection, particularly in patients with renal impairment [see Use in Specific Populations (8.6)] . Discontinue Cefazolin for Injection if seizures occur. Anticonvulsant therapy should be continued in patients with known seizure disorders. 5.3 Clostridioides difficile -Associated Diarrhea Clostridioides difficile -associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including cefazolin for injection, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile . C. difficile produces toxins A and B, which contribute to the development of CDAD. Hypertoxin-producing isolates of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibacterial drug use. Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents. If CDAD is suspected or confirmed, ongoing antibacterial drug use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibacterial drug treatment of C. difficile , and surgical evaluation should be instituted as clinically indicated. 5.4 Risk of Development of Drug-resistant Bacteria Prescribing Cefazolin for Injection in the absence of proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria. As with other antimicrobials, prolonged use of Cefazolin for Injection may result in overgrowth of nonsusceptible microorganisms. Repeated evaluation of the patient's condition is essential. Should superinfection occur during therapy, appropriate measures should be taken.

of the development of drug-resistant bacteria. As with other antimicrobials, prolonged use of Cefazolin for Injection may result in overgrowth of nonsusceptible microorganisms. Repeated evaluation of the patient's condition is essential. Should superinfection occur during therapy, appropriate measures should be taken. 5.5 Prothrombin Activity Cefazolin for Injection may be associated with a fall in prothrombin activity. Those at risk include patients with renal or hepatic impairment or poor nutritional state, as well as patients receiving a protracted course of antimicrobial therapy, and patients previously stabilized on anticoagulant therapy. Prothrombin time should be monitored in patients at risk and exogenous vitamin K administered as indicated. 5.6 Drug/Laboratory Test Interactions Urinary Glucose The administration of cefazolin may result in a false-positive reaction with glucose in the urine when using glucose tests based on Benedict’s copper reduction reaction that determine the amount of reducing substances like glucose in the urine. It is recommended that glucose tests based on enzymatic glucose oxidase reactions be used. Coombs’ Test Positive direct Coombs' tests have been reported during treatment with cefazolin. In hematologic studies or in transfusion cross-matching procedures when antiglobulin tests are performed on the minor side or in Coombs' testing of newborns whose mothers have received cephalosporin antibacterial drugs before parturition, it should be recognized that a positive Coombs' test may be due to the drug.

6 ADVERSE REACTIONS The following serious adverse reactions to cefazolin for injection are described below and elsewhere in the labeling: • Hypersensitivity Reactions to Cefazolin, Cephalosporins, Penicillins, or Other Beta-lactams [see Warnings and Precautions (5.1)] • Seizures in Patients with Renal Impairment [see Warnings and Precautions (5.2)] • Clostridioides difficile -Associated Diarrhea [see Warnings and Precautions (5.3)] Adult Patients : Most common adverse reactions: gastrointestinal (nausea, vomiting, diarrhea), and allergic reactions (anaphylaxis, urticaria, skin rash). (6) To report SUSPECTED ADVERSE REACTIONS, contact WG Critical Care, LLC at 1-866-562-4708 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The following adverse reactions were reported from clinical trials: Gastrointestinal: Diarrhea, oral candidiasis (oral thrush), mouth ulcers, vomiting, nausea, stomach cramps, epigastric pain, heartburn, flatus, anorexia and pseudomembranous colitis. Onset of pseudomembranous colitis symptoms may occur during or after antibacterial treatment [see Warnings and Precautions (5.3)] . Allergic: Anaphylaxis, eosinophilia, urticaria, itching, drug fever, skin rash, Stevens-Johnson syndrome. Hematologic: Neutropenia, leukopenia, thrombocytopenia, thrombocythemia. Hepatic: Transient rise in serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), and alkaline phosphatase levels has been observed. Reports of hepatitis have been received. Renal: Reports of increased BUN and creatinine levels, as well as renal failure, have been received. Local Reactions: Instances of phlebitis have been reported at site of injection. Some induration has occurred. Other Reactions: Pruritus (including genital, vulvar and anal pruritus, genital moniliasis, and vaginitis). Dizziness, fainting, lightheadedness, confusion, weakness, tiredness, hypotension, somnolence and headache. 6.2 Postmarketing Experience The following adverse reactions have been identified during post approval use of cefazolin. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Immune system disorders: Serum sickness-like reaction Renal and urinary disorders: Acute tubulointerstitial nephritis (ATIN) Skin and subcutaneous tissue disorders: Acute generalized exanthematous pustulosis (AGEP) 6.3 Cephalosporin-class Adverse Reactions In addition to the adverse reactions listed above that have been observed in patients treated with cefazolin, the following adverse reactions and altered laboratory tests have been reported for cephalosporin-class antibacterials: Stevens-Johnson syndrome, erythema multiforme, toxic epidermal necrolysis, renal impairment, toxic nephropathy, aplastic anemia, hemolytic anemia, hemorrhage, a fall in prothrombin activity, hepatic impairment including cholestasis, and pancytopenia.

7 DRUG INTERACTIONS The renal excretion of cefazolin is inhibited by probenecid. Co-administration of probenecid with Cefazolin for Injection is not recommended. Probenecid: The renal excretion of cefazolin is inhibited by probenecid. Co-administration of probenecid with Cefazolin for Injection is not recommended. (7)

8 USE IN SPECIFIC POPULATIONS 8.1 Pregnancy Risk Summary Available data from published prospective cohort studies, case series and case reports over several decades with cephalosporin use, including cefazolin, in pregnant women have not established a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. Cefazolin crosses the placenta. Animal reproduction studies with rats, mice and rabbits administered cefazolin during organogenesis at doses 1 to 3 times the maximum recommended human dose (MRHD) did not demonstrate adverse developmental outcomes. In rats subcutaneously administered cefazolin prior to delivery and throughout lactation, there were no adverse effects on offspring at a dose approximately 2 times the MRHD (see Data) . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Human Data While available studies cannot definitively establish the absence of risk, published data from case-control studies and case reports over several decades have not identified an association with cephalosporin use during pregnancy and major birth defects, miscarriage, or other adverse maternal or fetal outcomes. Available studies have methodologic limitations, including small sample size, retrospective data collection, and inconsistent comparator groups. Animal Data Reproduction studies have been performed in rats, mice and rabbits administered cefazolin during organogenesis at doses of 2000, 4000 and 240 mg/kg/day (approximately 1 to 3 times the maximum recommended human dose on a body surface area comparison). There was no evidence of any adverse effects on embryofetal development due to cefazolin. In a peripostnatal study in rats, cefazolin administered subcutaneously up to 1200 mg/kg/day (approximately 2 times the MRHD based on body surface area comparison) to pregnant dams prior to delivery and through lactation caused no adverse effects on offspring. 8.2 Lactation Risk Summary Data from published literature report that cefazolin is present in human milk but is not expected to accumulate in a breastfed infant. There are no data on the effects of cefazolin on the breastfed child or on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for Cefazolin for Injection and any potential adverse effects on the breastfed child from Cefazolin for Injection or from the mother’s underlying condition. 8.4 Pediatric Use Safety and effectiveness of Cefazolin for Injection for perioperative prophylaxis have not been established for pediatric patients. 8.5 Geriatric Use Of the 920 subjects who received cefazolin in clinical studies, 313 (34%) were 65 years and over, while 138 (15%) were 75 years and over. No overall differences in safety or effectiveness were observed between these subjects and younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.

75 years and over. No overall differences in safety or effectiveness were observed between these subjects and younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out. This drug is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, it may be useful to monitor renal function [see Warnings and Precautions (5.2)] . 8.6 Renal Impairment Recommendations for dosage adjustments or intervals for repeat dosing for perioperative prophylaxis in lengthy operative procedures or for postoperative use have not been established for adult patients with impaired renal function (creatinine clearance less than 55 mL/min).

8.1 Pregnancy Risk Summary Available data from published prospective cohort studies, case series and case reports over several decades with cephalosporin use, including cefazolin, in pregnant women have not established a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. Cefazolin crosses the placenta. Animal reproduction studies with rats, mice and rabbits administered cefazolin during organogenesis at doses 1 to 3 times the maximum recommended human dose (MRHD) did not demonstrate adverse developmental outcomes. In rats subcutaneously administered cefazolin prior to delivery and throughout lactation, there were no adverse effects on offspring at a dose approximately 2 times the MRHD (see Data) . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Human Data While available studies cannot definitively establish the absence of risk, published data from case-control studies and case reports over several decades have not identified an association with cephalosporin use during pregnancy and major birth defects, miscarriage, or other adverse maternal or fetal outcomes. Available studies have methodologic limitations, including small sample size, retrospective data collection, and inconsistent comparator groups. Animal Data Reproduction studies have been performed in rats, mice and rabbits administered cefazolin during organogenesis at doses of 2000, 4000 and 240 mg/kg/day (approximately 1 to 3 times the maximum recommended human dose on a body surface area comparison). There was no evidence of any adverse effects on embryofetal development due to cefazolin. In a peripostnatal study in rats, cefazolin administered subcutaneously up to 1200 mg/kg/day (approximately 2 times the MRHD based on body surface area comparison) to pregnant dams prior to delivery and through lactation caused no adverse effects on offspring.

8.5 Geriatric Use Of the 920 subjects who received cefazolin in clinical studies, 313 (34%) were 65 years and over, while 138 (15%) were 75 years and over. No overall differences in safety or effectiveness were observed between these subjects and younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out. This drug is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, it may be useful to monitor renal function [see Warnings and Precautions (5.2)] .

10 OVERDOSAGE Accidental overdosage resulting in seizures may occur in patients with renal impairment [see Warnings and Precautions (5.2)]. If seizures associated with accidental overdosage occur, discontinue Cefazolin for Injection and give supportive treatment.

11 DESCRIPTION Cefazolin for Injection USP is a semi-synthetic cephalosporin for parenteral administration. It is the sodium salt of 3-{[(5-methyl-1,3,4-thiadiazol-2-yl)thio]-methyl}-8-oxo-7-[2-(1 H -tetrazol-1-yl)acetamido]-5-thia-1-azabicyclo [4.2.0]oct‑2-ene-2-carboxylic acid. Structural Formula: C 14 H 13 N 8 NaO 4 S 3 M.W. 476.5 Cefazolin for Injection is supplied as a sterile powder in single-dose vials. The 2 g/vial Cefazolin for Injection contains 2 grams of cefazolin (equivalent to 2.097 g of cefazolin sodium). The 3 g/vial Cefazolin for Injection contains 3 grams of cefazolin (equivalent to 3.144 grams of cefazolin sodium). Each vial contains 48 mg of sodium per gram of cefazolin sodium. After reconstitution with sterile water for injection, the drug product solution has a pH of 4.0 to 6.0. Cefazolin for Injection, 2 grams/vial, is intended for intravenous infusion or intravenous bolus injection. Cefazolin for Injection, 2 grams/vial is not for intramuscular administration. Cefazolin for Injection, 3 grams/vial, is intended for intravenous infusion only. Cefazolin for Injection, 3 grams/vial is not for intravenous bolus injection or intramuscular administration [see Dosage and Administration (2.1, 2.2, 2.3)] . structural formula cefazolin

12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Cefazolin is an antibacterial drug [see Microbiology (12.4)] . 12.2 Pharmacodynamics The pharmacokinetic/pharmacodynamic relationship for cefazolin has not been evaluated in patients. 12.3 Pharmacokinetics Studies have shown that following intravenous administration of cefazolin to normal volunteers, mean serum concentrations peaked at approximately 185 mcg/mL and were approximately 4 mcg/mL at 8 hours for a 1 gram dose. In a study of constant intravenous infusion with dosages of 3.5 mg/kg for 1 hour (approximately 250 mg) and 1.5 mg/kg the next 2 hours (approximately 100 mg) in healthy volunteers, cefazolin serum concentrations at the third hour were approximately 28 mcg/mL. Plasma pharmacokinetic parameters of cefazolin in healthy volunteers (N=12) following a single 15-minute IV infusion of 2 grams of Cefazolin for Injection are summarized in Table 4. Table 4: Mean (Standard Deviation) Plasma Pharmacokinetic Parameters of Cefazolin in Healthy Volunteers N Cmax (mcg/mL) Tmax* (h) AUC0-inf (mcg*h/mL) t1/2 (h) CL (L/h) Vz (L) Single 2 grams Dose as a 15-Minute IV Infusion 12 280.9 (45.9) 0.25 (0.25-0.33) 509.9 (89.3) 2.01 (0.28) 4.03 (0.68) 11.50 (1.53) *Tmax reported as median (range) N= number of subjects observed; Cmax = maximum plasma concentration; Tmax = time to maximum plasma concentration; AUC0-inf = area under the plasma concentration-time curve extrapolated to infinity; t1/2 = apparent plasma terminal elimination half-life; CL = total clearance; Vz = volume of distribution Studies in patients hospitalized with infections indicate that cefazolin produces mean peak serum concentrations approximately equivalent to those seen in normal volunteers. Distribution Bile concentrations in patients without obstructive biliary disease can reach or exceed serum concentrations by up to five times; however, in patients with obstructive biliary disease, bile concentrations of cefazolin are considerably lower than serum concentrations (less than 1 mcg/mL). In synovial fluid, the cefazolin concentration becomes comparable to that reached in serum at about 4 hours after drug administration. Studies of cord blood show prompt transfer of cefazolin across the placenta. Cefazolin is present in very low concentrations in the milk of nursing mothers. Elimination The serum half-life for cefazolin is approximately 1.8 hours following IV administration. Excretion Cefazolin is excreted unchanged in the urine. In the first 6 hours approximately 60% of the drug is excreted in the urine and this increases to 70% to 80% within 24 hours. 12.4 Microbiology Mechanism of Action Cefazolin is a bactericidal agent that acts by inhibition of bacterial cell wall synthesis. Resistance Predominant mechanisms of bacterial resistance to cephalosporins include the presence of extended-spectrum beta-lactamases and enzymatic hydrolysis. Antimicrobial Activity Cefazolin has been shown to be active against most isolates of the following microorganisms, both in vitro and in clinical infections [ see Indications and Usage (1) ]: Aerobic bacteria Gram-Positive Bacteria Staphylococcus aureus Staphylococcus epidermidis Streptococcus agalactiae Streptococcus pneumoniae Streptococcus pyogenes Methicillin-resistant staphylococci are uniformly resistant to cefazolin.

ganisms, both in vitro and in clinical infections [ see Indications and Usage (1) ]: Aerobic bacteria Gram-Positive Bacteria Staphylococcus aureus Staphylococcus epidermidis Streptococcus agalactiae Streptococcus pneumoniae Streptococcus pyogenes Methicillin-resistant staphylococci are uniformly resistant to cefazolin. Gram-Negative Bacteria Escherichia coli Proteus mirabilis Most isolates of indole positive Proteus ( Proteus vulgaris ), Enterobacter spp., Morganella morganii, Providencia rettgeri, Serratia spp., and Pseudomonas spp. are resistant to cefazolin. Susceptibility Testing For specific information regarding susceptibility test interpretive criteria and associated test methods and quality control standards recognized by FDA for this drug, please see: https://www.fda.gov/STIC .

12.3 Pharmacokinetics Studies have shown that following intravenous administration of cefazolin to normal volunteers, mean serum concentrations peaked at approximately 185 mcg/mL and were approximately 4 mcg/mL at 8 hours for a 1 gram dose. In a study of constant intravenous infusion with dosages of 3.5 mg/kg for 1 hour (approximately 250 mg) and 1.5 mg/kg the next 2 hours (approximately 100 mg) in healthy volunteers, cefazolin serum concentrations at the third hour were approximately 28 mcg/mL. Plasma pharmacokinetic parameters of cefazolin in healthy volunteers (N=12) following a single 15-minute IV infusion of 2 grams of Cefazolin for Injection are summarized in Table 4. Table 4: Mean (Standard Deviation) Plasma Pharmacokinetic Parameters of Cefazolin in Healthy Volunteers N Cmax (mcg/mL) Tmax* (h) AUC0-inf (mcg*h/mL) t1/2 (h) CL (L/h) Vz (L) Single 2 grams Dose as a 15-Minute IV Infusion 12 280.9 (45.9) 0.25 (0.25-0.33) 509.9 (89.3) 2.01 (0.28) 4.03 (0.68) 11.50 (1.53) *Tmax reported as median (range) N= number of subjects observed; Cmax = maximum plasma concentration; Tmax = time to maximum plasma concentration; AUC0-inf = area under the plasma concentration-time curve extrapolated to infinity; t1/2 = apparent plasma terminal elimination half-life; CL = total clearance; Vz = volume of distribution Studies in patients hospitalized with infections indicate that cefazolin produces mean peak serum concentrations approximately equivalent to those seen in normal volunteers. Distribution Bile concentrations in patients without obstructive biliary disease can reach or exceed serum concentrations by up to five times; however, in patients with obstructive biliary disease, bile concentrations of cefazolin are considerably lower than serum concentrations (less than 1 mcg/mL). In synovial fluid, the cefazolin concentration becomes comparable to that reached in serum at about 4 hours after drug administration. Studies of cord blood show prompt transfer of cefazolin across the placenta. Cefazolin is present in very low concentrations in the milk of nursing mothers. Elimination The serum half-life for cefazolin is approximately 1.8 hours following IV administration. Excretion Cefazolin is excreted unchanged in the urine. In the first 6 hours approximately 60% of the drug is excreted in the urine and this increases to 70% to 80% within 24 hours.

<table width="549.9pt"><col width="21%"/><col width="8%"/><col width="12%"/><col width="12%"/><col width="13%"/><col width="11%"/><col width="11%"/><col width="11%"/><tbody><tr styleCode="Toprule"><td colspan="8" styleCode="Rrule Botrule Lrule Toprule " valign="top"><paragraph><content styleCode="bold">Table 4: Mean (Standard Deviation) Plasma Pharmacokinetic Parameters of Cefazolin in Healthy Volunteers </content></paragraph></td></tr><tr><td styleCode="Rrule Lrule Toprule Botrule " valign="top"/><td align="center" styleCode="Rrule Lrule Toprule Botrule " valign="middle"><paragraph><content styleCode="bold">N </content></paragraph></td><td styleCode="Rrule Lrule Toprule Botrule " valign="middle"><paragraph><content styleCode="bold">Cmax (mcg/mL) </content></paragraph></td><td styleCode="Rrule Lrule Toprule Botrule " valign="middle"><paragraph><content styleCode="bold">Tmax*</content></paragraph><paragraph><content styleCode="bold">(h) </content></paragraph></td><td styleCode="Rrule Lrule Toprule Botrule " valign="middle"><paragraph><content styleCode="bold">AUC0-inf (mcg*h/mL) </content></paragraph></td><td styleCode="Rrule Lrule Toprule Botrule " valign="middle"><paragraph><content styleCode="bold">t1/2 </content></paragraph><paragraph><content styleCode="bold">(h) </content></paragraph></td><td styleCode="Rrule Lrule Toprule Botrule " valign="middle"><paragraph><content styleCode="bold">CL (L/h) </content></paragraph></td><td styleCode="Rrule Lrule Toprule Botrule " valign="middle"><paragraph><content styleCode="bold">Vz (L) </content></paragraph></td></tr><tr styleCode="Botrule"><td styleCode="Rrule Botrule Lrule Toprule " valign="top"><paragraph>Single 2 grams Dose as a 15-Minute IV Infusion </paragraph></td><td align="center" styleCode="Rrule Botrule Lrule Toprule " valign="middle"><paragraph>12 </paragraph></td><td styleCode="Rrule Botrule Lrule Toprule " valign="middle"><paragraph>280.9 (45.9) </paragraph></td><td styleCode="Rrule Botrule Lrule Toprule " valign="middle"><paragraph>0.25</paragraph><paragraph>(0.25-0.33) </paragraph></td><td styleCode="Rrule Botrule Lrule Toprule " valign="middle"><paragraph>509.9 (89.3) </paragraph></td><td styleCode="Rrule Botrule Lrule Toprule " valign="middle"><paragraph>2.01 (0.28) </paragraph></td><td styleCode="Rrule Botrule Lrule Toprule " valign="middle"><paragraph>4.03 (0.68) </paragraph></td><td styleCode="Rrule Botrule Lrule Toprule " valign="middle"><paragraph>11.50 (1.53) </paragraph></td></tr></tbody></table>

13 NONCLINICAL TOXICOLOGY 13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility Carcinogenesis and Mutagenesis Mutagenicity studies and long-term studies in animals to determine the carcinogenic potential of Cefazolin for Injection have not been performed. Impairment of Fertility Fertility studies conducted in rats subcutaneously administered cefazolin at doses of 2000 mg/kg/day (approximately 3 times the maximum recommended human dose based on body surface area comparison) showed no impairment of mating and fertility.

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility Carcinogenesis and Mutagenesis Mutagenicity studies and long-term studies in animals to determine the carcinogenic potential of Cefazolin for Injection have not been performed. Impairment of Fertility Fertility studies conducted in rats subcutaneously administered cefazolin at doses of 2000 mg/kg/day (approximately 3 times the maximum recommended human dose based on body surface area comparison) showed no impairment of mating and fertility.

16 HOW SUPPLIED/STORAGE AND HANDLING Cefazolin for Injection, USP is available in a single-dose vial containing 2 grams or 3 grams of cefazolin as a white to cream colored powder for reconstitution. Each vial contains cefazolin sodium equivalent to 2 grams or 3 grams of cefazolin, and is supplied as follows: 2 grams per Single-Dose Vial: NDC 44567-840-01 Carton of 25: NDC 44567-840-25 3 grams per Single-Dose Vial: NDC 44567-845-01 Carton of 25: NDC 44567-845-25 Store Cefazolin for Injection vials at 20°C to 25°C (68°F to 77°F) [see USP Controlled Room Temperature]. Protect from Light. Storage conditions for the reconstituted and diluted solutions are described elsewhere in labeling [see Dosage and Administration (2.3)].

17 PATIENT COUNSELING INFORMATION Serious Allergic Reactions Advise patients that allergic reactions, including serious allergic reactions could occur and that serious reactions require immediate treatment and discontinuation of Cefazolin for Injection. Patients should report to their health care provider any previous allergic reactions to cefazolin, cephalosporins, penicillins, or other similar antibacterials [see Warnings and Precautions (5.1)] . Seizures Advise patients that seizures could occur with Cefazolin for Injection. Instruct patients to inform a healthcare provider at once of any signs and symptoms of seizures, for immediate treatment or discontinuation of Cefazolin for Injection [see Warnings and Precautions (5.2)] . Diarrhea Advise patients that diarrhea is a common problem caused by antibacterials including cefazolin for injection, which usually ends when the antibacterial is discontinued. Sometimes after starting treatment with antibacterials, including Cefazolin for Injection, patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as two or more months after having taken the last dose of the antibacterials. If this occurs, patients should contact a physician as soon as possible [see Warnings and Precautions (5.3)] . Antibacterial Resistance Patients should be counseled that antibacterial drugs, including Cefazolin for Injection should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When Cefazolin for Injection is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by Cefazolin for Injection or other antibacterial drugs in the future [see Warnings and Precautions (5.4)] . Manufactured for: WG Critical Care, LLC Paramus, NJ 07652 Made in Italy