Cefazolin sodium is a semisynthetic, first generation cephalosporin antibiotic.
Uses
Cefazolin is used for the treatment of respiratory tract infections, urinary tract infections, skin and skin structure infections, biliary tract infections, bone and joint infections, genital infections, septicemia, and endocarditis caused by susceptible bacteria. The drug also is used for perioperative prophylaxis. In addition, cefazolin is used as an alternative to amoxicillin or ampicillin for prevention of a-hemolytic (viridans group) streptococcal endocarditis in penicillin-allergic individuals considered to be at risk for bacterial endocarditis following certain dental or upper respiratory tract procedures and as an alternative to penicillin G or ampicillin for prevention of perinatal group B streptococcal disease in pregnant women hypersensitive to penicillins.
Gram-positive Aerobic Bacterial Infections
Cefazolin is used in the treatment of respiratory tract infections caused by Streptococcus pneumoniae, Staphylococcus aureus (penicillin-susceptible and penicillin-resistant strains), and S. pyogenes (group A b-hemolytic streptococci); urinary tract or genital infections caused by enterococci; skin and skin structure infections caused by S. aureus (penicillin-susceptible and penicillin-resistant strains), S. pyogenes, and other streptococci; biliary tract or bone and joint infections caused by S. aureus; septicemia caused by S. pneumoniae or S. aureus (penicillin-susceptible and penicillin-resistant strains); and endocarditis caused by S. aureus (penicillin-susceptible and penicillin-resistant strains), and S. pyogenes. Although cefazolin usually is effective in eradicating S. pyogenes from the nasopharynx, efficacy of the drug in the subsequent prevention of rheumatic fever remains to be established.
Gram-negative Aerobic Bacterial Infections
Cefazolin is used in the treatment of respiratory tract infections caused by Klebsiella or Haemophilus influenzae; biliary tract infections caused by Escherichia coli, Proteus mirabilis, or Klebsiella; urinary tract infections caused by E. coli, P. mirabilis, Klebsiella, and some strains of Enterobacter; genital infections (i.e., prostatitis, epididymitis) caused by E. coli, P. mirabilis, or Klebsiella; and septicemia caused by P. mirabilis, E. coli, or Klebsiella.
Prevention of Perinatal Group B Streptococcal Disease
Cefazolin is used as an alternative to penicillin G or ampicillin for prevention of perinatal group B streptococcal (GBS) disease. Pregnant women who are colonized with GBS in the genital or rectal areas can transmit GBS infection to their infants during labor and delivery resulting in invasive neonatal infection that can be associated with substantial morbidity and mortality. Intrapartum anti-infective prophylaxis for prevention of early-onset neonatal GBS disease is administered selectively to women at high risk for transmitting GBS infection to their neonates. The US Centers for Disease Control and Prevention (CDC) recommends routine universal prenatal culture-based screening for GBS colonization in all pregnant women at 35-37 weeks gestation, unless GBS bacteriuria is known to be present during the current pregnancy or the women had a previous infant with invasive GBS disease. The CDC states that prevention of perinatal GBS is indicated in pregnant women identified as GBS carriers during routine prenatal GBS screening (vaginal and rectal cultures) performed at 35-37 weeks during the current pregnancy; in women with GBS bacteriuria during the current pregnancy; in women with a previous infant with invasive GBS disease; and in women with unknown GBS status with delivery at less than 37 weeks gestation, duration of amniotic membrane rupture 18 hours or longer, or intrapartum temperature of 38°C or higher. Such prophylaxis is initiated at the time of labor or rupture of membranes. When intrapartum prophylaxis is indicated in the mother, the CDC and American Academy of Pediatrics (AAP) recommend penicillin G (5 million units IV initially followed by 2.5 million units IV every 4 hours until delivery) as the regimen of choice and ampicillin (2 g IV initially followed by 1 g IV every 4 hours until delivery) as the preferred alternative. When intrapartum prophylaxis to prevent GBS in the neonate is indicated in women who are hypersensitive to penicillins, a regimen of IV clindamycin (900 mg IV every 8 hours until delivery) or IV erythromycin (500 mg IV every 6 hours until delivery) is recommended for those allergic to penicillins who are at high risk for anaphylaxis (e.g., those with a history of immediate penicillin hypersensitivity, such as anaphylaxis, angioedema, or urticaria; those with a history of asthma or other conditions that would make anaphylaxis more dangerous or difficult to treat, including individuals receiving β-adrenergic blocking agents). For those allergic to penicillins who are not at high risk for anaphylaxis, the CDC states that a regimen of IV cefazolin (2 g IV initially followed by 1 g IV every 8 hours until delivery) should be used since this cephalosporin has a narrow spectrum of activity and is associated with high intraamniotic concentrations. The fact that GBS with in vitro resistance to clindamycin and erythromycin have been reported with increasing frequency should be considered when choosing an alternative to penicillins. Vancomycin should be used for intrapartum prophylaxis of perinatal GBS disease only in women with penicillin allergy who are at high risk for anaphylaxis and only when GBS isolates are known or likely to be resistant to clindamycin and erythromycin. For additional information on prevention of perinatal group B streptococcal disease, see Uses: Prevention of Perinatal Group B Streptococcal Disease, in the Natural Penicillins General Statement 8:12..04.
Perioperative Prophylaxis
Cefazolin has been effective when used perioperatively to reduce the incidence of infection in patients undergoing surgical procedures classified as contaminated or potentially contaminated (e.g., vaginal hysterectomy, high-risk cesarean section, cholecystectomy in high-risk patients) and in those undergoing surgical procedures in which the development of infection at the surgical site would represent a serious risk (e.g., cardiac surgery, prosthetic arthroplasty). There is evidence that perioperative prophylaxis with an appropriate anti-infective agent can decrease the incidence of infection, particularly wound infection, after certain procedures; however, such prophylaxis usually is recommended only for procedures with a high rate of infection, procedures involving implantation of prosthetic material, and procedures in which the consequences of infection are especially serious. Because cefazolin has a narrow spectrum of activity that covers the most likely surgical site pathogens, has a moderately long serum half-life, and has been shown to be effective, it is considered by many clinicians to be the drug of choice for perioperative prophylaxis for a variety of procedures, including cardiac, noncardiac thoracic, esophageal, gastroduodenal, biliary tract, gynecologic and obstetric, head and neck, neurologic, orthopedic, and vascular surgeries. However, a drug or regimen with activity against anaerobic bacteria (e.g., cefotetan or cefoxitin with or without gentamicin; cefazolin and metronidazole; clindamycin with or without gentamicin) generally is preferred for surgery involving the distal intestinal tract or ruptured viscus, including colorectal surgery and appendectomy. (See Uses: Perioperative Prophylaxis, in the Cephalosporins General Statement 8:12.06.)
Timing and Number of Doses
When perioperative prophylaxis is indicated in patients undergoing clean-contaminated or potentially contaminated surgery, administration of the anti-infective should be timed to ensure that bactericidal concentrations of the drug are established in serum and tissues by the time the initial surgical incision is made; therapeutic concentrations of the drug should then be maintained in serum and tissues throughout the operation and until, at most, a few hours after the incision is closed. With many anti-infectives (e.g., cefazolin), a single dose given no more than 30 minutes before the incision provides adequate tissue concentrations throughout the procedure. If surgery is prolonged (more than 4 hours) or major blood loss occurs, it may be advisable to administer one or more additional doses during the procedure; for prolonged procedures, some clinicians suggest that intraoperative doses be administered every 4-8 hours for the duration of the procedure. Although anti-infective prophylaxis regimens reported in published studies often include 1 or 2 postoperative doses in addition to the preoperative dose, many clinicians state that postoperative doses generally are unnecessary. Continuation of prophylaxis after surgery appears to be of no additional value and may increase the risk of toxicity and bacterial superinfection. If signs of infection occur following surgery, specimens should be obtained for identification of the causative organism and appropriate therapy instituted.
Contaminated Surgery
Patients undergoing contaminated or dirty surgery, such as that involving a perforated abdominal viscus, a compound fracture, a traumatic wound, or a laceration due to an animal or human bite are at risk for infection. When used in patients undergoing these procedures, anti-infective therapy is considered treatment rather than prophylaxis and is continued postoperatively for about 5 days. Some clinicians recommend use of a regimen of IV cefoxitin or IV cefotetan (with or without IV gentamicin) or, alternatively, a regimen of IV clindamycin and IV gentamicin for patients undergoing surgery involving a ruptured viscus; if ruptured viscus occurs in a postoperative setting (dehiscence), anti-infective coverage of nosocomial pathogens should be included. Cefazolin generally is the preferred anti-infective in patients undergoing surgery involving a traumatic wound; some clinicians state that if a bitewound is involved, an anti-infective against anaerobes (e.g., amoxicillin and clavulanate potassium or ampicillin sodium and sulbactam sodium) should be used. For penetrating intracranial wounds, including gunshot injuries, a broad-spectrum anti-infective such as ampicillin sodium and sulbactam sodium is recommended.
Administration
Reconstitution and Administration
Cefazolin sodium is administered by IV injection or infusion or by deep IM injection. The drug has also been administered intraperitoneally in dialysis solutions.
Intermittent IV Injection
For direct IV injection, vials labeled as containing 500 mg or 1 g of cefazolin should be reconstituted with 2 or 2.5 mL, respectively, of sterile water for injection to provide solutions containing approximately 225 or 330 mg/mL, respectively. These solutions should be further diluted in approximately 5 mL of sterile water for injection, or according to the manufacturers’ directions. The appropriate dose should then be injected over a period of 3-5 minutes directly into a vein or the tubing of a freely flowing compatible IV solution.
Intermittent or Continuous IV Infusion
For intermittent IV infusion, reconstituted solutions of cefazolin containing approximately 225 or 330 mg/mL should be further diluted in 50-100 mL of a compatible IV solution. Alternatively, piggyback units; ADD-Vantage® vials labeled as containing 500 mg or 1 g of cefazolin; and 10- or 20-g pharmacy bulk packages of the drug should be reconstituted and administered according to the manufacturers’ directions. The cefazolin pharmacy bulk packages are not intended for direct IV infusion; doses of the drug from the reconstituted bulk packages must be further diluted in a compatible IV infusion solution prior to administration. Thawed solutions of commercially available frozen cefazolin sodium injections should be administered only by intermittent or continuous IV infusion. The commercially available frozen cefazolin sodium in dextrose injections should not be thawed by warming them in a water bath or by exposure to microwave radiation. A precipitate may form while the commercially available injection in dextrose is frozen; however, this usually will dissolve with little or no agitation upon reaching room temperature, and the potency of cefazolin sodium frozen injection is not affected. After thawing at room temperature or under refrigeration, the containers should be checked for minute leaks by firmly squeezing the bag. The injections should be discarded if the container seal or outlet ports are not intact or leaks are found or if the solutions are cloudy or contain a precipitate. Additives should not be introduced into the injection container. The injections should not be used in series connections with other plastic containers, since such use could result in air embolism from residual air being drawn from the primary container before administration of fluid from the secondary container is complete.
IM Injection
IM injections of cefazolin sodium are prepared by reconstituting vials labeled as containing 500 mg or 1 g of cefazolin with 2 or 2.5 mL, respectively, of sterile water for injection to provide solutions containing approximately 225 or 330 mg/mL, respectively. IM injections of cefazolin should be made deeply into a large muscle mass.
Dosage
Dosage of cefazolin sodium is expressed in terms of cefazolin and is identical for IM or IV administration.
Adult Dosage
The usual adult dosage of cefazolin is 250 mg every 8 hours to 1.5 g every 6 hours, depending on the severity of the infection and the susceptibility of the causative organism. In severe, life-threatening infections, up to 12 g daily may be required.
Prevention of Bacterial Endocarditis
If cefazolin is used as an alternative to amoxicillin or ampicillin for prevention of a-hemolytic (viridans group) streptococcal endocarditis in penicillin-allergic individuals considered to be at risk for bacterial endocarditis following certain dental or upper respiratory tract procedures, adults should receive a single 1-g IM or IV dose administered within 30 minutes prior to the procedure. Cefazolin should not be used for such prophylaxis in individuals with a history of immediate-type hypersensitivity reactions to penicillin (e.g., urticaria, angioedema, anaphylaxis). For information regarding indications for prophylaxis against bacterial endocarditis, see Uses: Prevention of Bacterial Endocarditis, in the Aminopenicillins General Statement 8:12..08.
Prevention of Perinatal Group B Streptococcal Disease
If cefazolin is used for intrapartum anti-infective prophylaxis for prevention of perinatal group B streptococcal (GBS) disease in women with penicillin hypersensitivity who are not at risk for anaphylaxis, the US Centers for Disease Control and Prevention (CDC) recommends that an initial 2-g IV dose of cefazolin be given followed by 1 g IV every 8 hours until delivery. When indicated, such prophylaxis is initiated at the time of labor or rupture of membranes. (See Uses: Prevention of Perinatal Group B Streptococcal Disease.) Perioperative
Prophylaxis
For perioperative prophylaxis in contaminated or potentially contaminated surgery, the manufacturers recommend that adults receive 1 g of cefazolin IM or IV 30-60 minutes prior to surgery and 0.5-1 g IM or IV every 6-8 hours for 24 hours postoperatively. In lengthy operations (e.g., 2 hours or longer), additional doses of 0.5-1 g may be given IM or IV during the procedure. When the occurrence of infection may be particularly devastating (e.g., in prosthetic arthroplasty), the manufacturers state that prophylaxis may be continued for 3-5 days postoperatively. For perioperative prophylaxis in patients undergoing cardiac surgery (prosthetic valve, coronary artery bypass, other open-heart surgery, pacemaker or defibrillator implant); noncardiac thoracic surgery; vascular surgery (arterial surgery involving the abdominal aorta, a prosthesis, or a groin incision or lower extremity amputation for ischemia); neurosurgery (craniotomy); orthopedic surgery (total joint replacement, internal fixation of fractures); GI surgery (gastroduodenal, esophageal, biliary tract), or head and neck surgery (involving incisions through oral or pharyngeal mucosa), many clinicians recommend that 1-2 g of cefazolin be given IV just prior to the procedure. For colorectal surgery, some clinicians recommend that 1-2 g of cefazolin be given IV just prior to surgery in conjunction with IV metronidazole (0.5 g). For perioperative prophylaxis in patients undergoing gynecologic and obstetric surgery (i.e., vaginal or abdominal hysterectomy, second trimester abortion), many clinicians recommend that 1-2 g of cefazolin be given IV immediately prior to the procedure; for those undergoing cesarean section, a single 1- or 2-g IV dose of cefazolin should be given immediately after the umbilical cord is clamped. Some clinicians suggest that additional intraoperative doses of cefazolin be given at 4- to 8-hour intervals during prolonged procedures; additional doses also are advisable if substantial blood loss occurs. In patients undergoing open-heart surgery, some clinicians recommend that an additional dose be given when the patient is removed from bypass. Although the manufacturers and some clinicians suggest that perioperative prophylaxis be continued for at least 48 hours after cardiothoracic surgery, most clinicians believe that postoperative doses usually are unnecessary for most procedures. If cefazolin is used following contaminated or dirty surgery that involves a traumatic wound, some clinicians suggest that 1-2 g should be given IV every 8 hours. When used in this situation, the drug should be continued postoperatively for about 5 days and is considered treatment rather than prophylaxis.
Pediatric Dosage
The usual dosage of cefazolin for the treatment of mild to moderately severe infections in pediatric patients older than 1 month of age is 25-50 mg/kg daily given in 3 or 4 equally divided doses. In severe infections, a pediatric dosage of 50-100 mg/kg daily given in 3 or 4 equally divided doses may be required. Safe use of cefazolin in premature infants and in neonates younger than 1 month of age has not been established.
Prevention of Bacterial Endocarditis
If cefazolin is used as an alternative to amoxicillin or ampicillin for prevention of a-hemolytic (viridans group) streptococcal endocarditis in penicillin-allergic individuals considered to be at risk for bacterial endocarditis following certain dental or upper respiratory tract procedures, pediatric patients should receive a single 25-mg/kg IM or IV dose administered within 30 minutes prior to the procedure. Cefazolin should not be used for such prophylaxis in individuals with a history of immediate-type hypersensitivity reactions to penicillin (e.g., urticaria, angioedema, anaphylaxis). For information regarding indications for prophylaxis against bacterial endocarditis, see Uses: Prevention of Bacterial Endocarditis, in the Aminopenicillins General Statement 8:12.16.08.
Dosage in Renal Impairment
In patients with impaired renal function, doses and/or frequency of administration of cefazolin must be modified in response to the degree of impairment, severity of the infection, susceptibility of the causative organism, and serum concentrations of the drug. There is a wide variation in dosage recommendations for these patients. The manufacturers recommend an initial loading dose of cefazolin for adults (usually 500 mg). For subsequent therapy, the manufacturers recommend that adults with steady-state creatinine clearances of 55 mL/minute or greater or serum creatinine of 1.5 mg/dL or less receive full doses; adults with steady-state creatinine clearances of 35-54 mL/minute or serum creatinine of 1.6-3.0 mg/dL receive full doses, but at intervals of at least 8 hours; adults with steady-state creatinine clearances of 11-34 mL/minute or serum creatinine of 3.1-4. mg/dL receive one-half the usual dose every 12 hours; and adults with steady-state creatinine clearances of less than 10 mL/minute or serum creatinine of 4.6 mg/dL or greater receive one-half the usual dose every 18-24 hours. Pediatric patients with mild renal impairment (steady-state creatinine clearances of 40-70 mL/minute) should receive 60% of the usual daily dose, divided equally and administered every 12 hours; those with moderate renal impairment (steady-state creatinine clearances of 20-40 mL/minute) should receive 25% of the usual daily dose, divided equally and administered every 12 hours; and those with severe renal impairment (steady-state creatinine clearances of 5-20 mL/minute) should receive 10% of the usual daily dose every 24 hours. Spectrum Based on its spectrum of activity, cefazolin is classified as a first generation cephalosporin. For information on the classification of cephalosporins and closely related b-lactam antibiotics based on spectra of activity, see Spectrum in the Cephalosporins General Statement 8:12.06. Like other first generation cephalosporins (e.g., cefadroxil, cephalexin, cephradine), cefazolin is active in vitro against many gram-positive aerobic cocci but has limited activity against gram-negative bacteria.
Pharmacokinetics
Absorption
Cefazolin sodium is not appreciably absorbed from the GI tract and must be administered parenterally. Following IM administration of cefazolin sodium in healthy adults with normal renal function, peak serum cefazolin concentrations are attained within 1-2 hours and average 17 mcg/mL following a single 250-mg dose, 30-44 mcg/mL following a single 500-mg dose, and 64-76 mcg/mL following a single 1-g dose. Following a single 1-g IV dose in adults with normal renal function, serum concentrations of cefazolin average 188 mcg/mL at 5 minutes, 74 mcg/mL at 1 hour, and 46 mcg/mL at 2 hours. In one study in adults with normal renal function, steady-state serum concentrations of cefazolin were reached 3 hours after IV infusion of 3.5 mg/kg over 1 hour followed by 1.5 mg/kg over 2 hours. In one study in children, peak serum concentrations of cefazolin occurred at 30 minutes and averaged 28 mcg/mL after a single cefazolin IM dose of 5-6. mg/kg and 42 mcg/mL after a single IM dose of 10-12. mg/kg.
Elimination
The serum half-life of cefazolin is 1.2-2. hours in adults with normal renal function. In one study, half-life was 6.8 hours in 1 adult with a creatinine clearance of 26 mL/minute, 12 hours in 3 adults with creatinine clearances of 12-17 mL/minute, and 57 hours in 3 adults with creatinine clearances less than 5 mL/minute. Cefazolin is excreted unchanged in urine. Approximately 60% of a single IM or IV dose of cefazolin is excreted within 6 hours and 80-100% of the dose is excreted within 24 hours in adults with normal renal function. In adults with normal renal function, peak urinary cefazolin concentrations of about 2 or 4 mg/mL may be attained following a single 500-mg or 1-g IM dose, respectively, of the drug.
Chemistry and Stability
Chemistry
Cefazolin sodium is a semisynthetic cephalosporin antibiotic. Cefazolin sodium occurs as a white to off-white, crystalline powder which may have a faint odor or as a white to off-white lyophilized solid. The drug is freely soluble in water and very slightly soluble in alcohol. Each gram of cefazolin as the sodium salt contains approximately 2 mEq of sodium. When reconstituted as directed, cefazolin sodium solutions are light yellow to yellow and have a pH of 4.5-6. Commercially available frozen cefazolin sodium injections containing 500 mg or 1 g of cefazolin in 50 mL of 5% dextrose injection have osmolalities of 260-320 or 310-380 mOsm/kg, respectively, and have a pH of 4.5-7.
Stability
Cefazolin sodium and solutions of the drug should be protected from light. Cefazolin sodium sterile powder should be stored at a controlled room temperature of 20-25°C, but may be exposed to temperatures ranging from 15-30°C. Cefazolin sodium powder tends to darken, depending on storage conditions; however, such discoloration does not indicate loss of potency. The manufacturer states that the stability of the commercially available frozen cefazolin sodium injections may vary. These injections are stable for at least 90 days from the date of shipment when stored at a temperature not greater than -20°C. Following reconstitution with sterile water for injection, solutions containing approximately 225 or 330 mg of cefazolin per mL are pale yellow to yellow in color and are stable for 24 hours at room temperature or 10 days at 5°C. Reconstituted solutions have a pH of approximately 4.5-6; rapid hydrolysis of the drug occurs when pH exceeds 8.5, and precipitation of the insoluble free acid may occur when pH is below 4.5. Solutions containing 2.25-4. mg of cefazolin per mL are stable for 24 hours at room temperature or 96 hours at 5°C in the following infusion fluids: 0.9% sodium chloride; 5% or 10% dextrose; 5% dextrose and 0.2%, 0.45%, or 0.9% sodium chloride; 5% dextrose and lactated Ringer’s; Ringer’s; lactated Ringer’s; 5% or 10% invert sugar in water; Normosol®-M in D5-W; Ionosol® B with 5% dextrose; Plasma-Lyte® with 5% dextrose; and 5% sodium carbonate. The manufacturer of Ancef® states that these cefazolin sodium solutions are stable for 10 days when refrigerated. Solutions containing approximately 225 or 330 mg of cefazolin per mL may be frozen in their original containers immediately after reconstitution with sterile water for injection and are stable for 12 weeks when stored at -20°C. If the solutions are warmed to facilitate thawing, care should be taken to avoid heating after thawing has been completed. Once thawed, solutions should not be refrozen. C ommercially available frozen cefazolin sodium injections are stable for 24 months when stored at -20°C. The frozen injections should be thawed at room temperature (25°C) or under refrigeration (5°C), and once thawed, should not be refrozen. Thawed solutions of the commercially available frozen injections are stable for 48 hours at room temperature (25°C) or 30 days when refrigerated at 5°C. If the commercially available frozen cefazolin sodium injections are refrigerated immediately after removal from the freezer, the injections are stable for a total of 12 days (i.e., 10 days at 5°C followed by 48 hours at room temperature). Solutions that have been thawed and stored at room temperature for up to 24 hours may then be refrigerated at 5°C for up to 3 days and stored for an additional 24 hours at room temperature; this recycling procedure must be completed within 11 days from the time of thawing. The commercially available frozen injections of the drug are provided in a plastic container fabricated from specially formulated polyvinyl chloride (PVC). Solutions in contact with the plastic can leach out some of its chemical components in very small amounts (e.g., bis(2-ethylhexyl)phthalate [BEHP, DEHP]in up to 5 ppm) within the expiration period of the injections; however, safety of the plastic has been confirmed in tests in animals according to USP biological tests for plastic containers as well as by tissue culture toxicity studies. For further information on chemistry, mechanism of action, spectrum, resistance, pharmacokinetics, uses, cautions, drug interactions, laboratory test interferences, and dosage and administration of cefazolin, see the Cephalosporins General Statement 8:12.06.
Preparations
Cefazolin Sodium Parenteral For injection 500 mg (of cefazolin) Ancef®, GlaxoSmithKline Cefazolin Sodium for Injection , American Pharmaceutical Partners Sandoz 1 g (of cefazolin) Ancef®, GlaxoSmithKline Cefazolin Sodium for Injection , American Pharmaceutical Partners Sandoz 10 g (of cefazolin) pharmacy Ancef®, bulk package GlaxoSmithKline Cefazolin Sodium for Injection , American Pharmaceutical Partners Sandoz 20 g (of cefazolin) pharmacy Cefazolin Sodium for Injection bulk package , American Pharmaceutical Partners For injection, for 1 g (of cefazolin) Ancef® Piggyback, IV infusion Abbott Cefazolin Sodium ADD-Vantage®, (with 0.04% polysorbate 80) Abbott Cefazolin Sodium for Injection Piggyback, American Pharmaceutical Partners Sandoz Cefazolin Sodium in Dextrose Parenteral Injection (frozen) 10 mg (of cefazolin) per mL Cefazolin Sodium in 5% , for IV infusion (500 mg) in 5% Dextrose Dextrose Injection, (Galaxy®) Baxter 20 mg (of cefazolin) per mL Cefazolin Sodium in 5% (1 g) in 5% Dextrose Dextrose Injection, (Galaxy®) Baxter