Cefizox (Page 3 of 6)

Anaerobic Techniques:

For anaerobic bacteria, the susceptibility to ceftizoxime as MICs can be determined by standardized test methods. Agar dilution results can vary widely when using ceftizoxime. It is recommended that broth microdilution method be used when possible.3 The MIC values obtained should be interpreted according to following criteria:

Broth dilution Agar dilution Interpretation
≤ 16 ≤ 32 Susceptible (S)
32 64 Intermediate (I)
≥ 64 ≥ 128 Resistant (R)

Interpretation is identical to that described in Susceptibility Testing: Dilution Techniques.

As with other susceptibility techniques, the use of laboratory control microorganisms is required to control the technical aspects of the laboratory standardized procedures. Standardized ceftizoxime powder should provide the following MIC values:


Broth dilution Agar dilution
Eubacterium lentum ATCC 43055 16-64 16-64
Bacteriodes thetaiotaomicron ATCC 29741 4-16

Susceptibility Testing for Pseudomonas in Urinary Tract Infections

Most strains of Pseudomonas aeruginosa are moderately susceptible to ceftizoxime.

Ceftizoxime achieves high levels in the urine (greater than 6000 μg/mL at 2 hours with

1 gram IV) and, therefore, the following zone sizes should be used when testing

ceftizoxime for treatment of urinary tract infections caused by Pseudomonas


Susceptible organisms produce zones of 20 mm or greater, indicating that the

test organism is likely to respond to therapy.

Organisms that produce zones of 11 to 19 mm are expected to be susceptible

when the infection is confined to the urinary tract (in which high antibiotic levels

are attained).

Resistant organisms produce zones of 10 mm or less, indicating that other

therapy should be selected.

Indications and Usage

Cefizox (ceftizoxime for injection, USP) is indicated in the treatment of infections due to susceptible strains of the microorganisms listed below.

Lower Respiratory Tract Infections caused by Klebsiella spp.; Proteus mirabilis ; Escherichia coli; Haemophilus influenzae including ampicillin­resistant strains; Staphylococcus aureus (penicillinase­ and nonpenicillinase­producing); Serratia spp.; Enterobacter spp.; Bacteroides spp.; and Streptococcus spp. including S. pneumoniae , but excluding enterococci.

Urinary Tract Infections caused by Staphylococcus aureus (penicillinase­ and nonpenicillinase­producing); Escherichia coli ; Pseudomonas spp. including P. aeruginosa ; Proteus mirabilis ; P. vulgaris ; Providencia rettgeri (formerly Proteus rettgeri) and Morganella morganii (formerly Proteus morganii); Klebsiella spp.; Serratia spp. including S. marcescens ; and Enterobacter spp.

Gonorrhea including uncomplicated cervical and urethral gonorrhea caused by Neisseria gonorrhoeae.

Pelvic Inflammatory Disease caused by Neisseria gonorrhoeae, Escherichia coli or Streptococcus agalactiae. NOTE: Ceftizoxime, like other cephalosporins, has no activity against Chlamydia trachomatis. Therefore, when cephalosporins are used in the treatment of patients with pelvic inflammatory disease and C. trachomatis is one of the suspected pathogens, appropriate anti­chlamydial coverage should be added.

Intra­Abdominal Infections caused by Escherichia coli; Staphylococcus epidermidis; Streptococcus spp. (excluding enterococci); Enterobacter spp.; Klebsiella spp.; Bacteroides spp. including B. fragilis ; and anaerobic cocci, including Peptococcus spp. and Peptostreptococcus spp.

Septicemia caused by Streptococcus spp. including S. pneumoniae (but excluding enterococci); Staphylococcus aureus (penicillinase­ and nonpenicillinase­producing); Escherichia coli; Bacteroides spp. including B. fragilis ; Klebsiella spp.; and Serratia spp.

Skin and Skin Structure Infections caused by Staphylococcus aureus (penicillinase­ and nonpenicillinase­producing); Staphylococcus epidermidis ; Escherichia coli; Klebsiella spp.; Streptococcus spp. including Streptococcus pyogenes (but excluding enterococci); Proteus mirabilis ; Serratia spp.; Enterobacter spp.; Bacteroides spp. including B. fragilis ; and anaerobic cocci, including Peptococcus spp. and Peptostreptococcus spp.

Bone and Joint Infections caused by Staphylococcus aureus (penicillinase­ and nonpenicillinase­producing); Streptococcus spp. (excluding enterococci); Proteus mirabilis ; Bacteroides spp.; and anaerobic cocci, including Peptococcus spp. and Peptostreptococcus spp.

Meningitis caused by Haemophilus influenzae. Cefizox has also been used successfully in the treatment of a limited number of pediatric and adult cases of meningitis caused by Streptococcus pneumoniae.

Cefizox has been effective in the treatment of seriously ill, compromised patients, including those who were debilitated, immunosuppressed, or neutropenic.

Infections caused by aerobic gram­negative and by mixtures of organisms resistant to other cephalosporins, aminoglycosides, or penicillins have responded to treatment with Cefizox.

Because of the serious nature of some urinary tract infections due to P. aeruginosa and because many strains of Pseudomonas species are only moderately susceptible to Cefizox, higher dosage is recommended. Other therapy should be instituted if the response is not prompt.

Susceptibility studies on specimens obtained prior to therapy should be used to determine the response of causative organisms to Cefizox. Therapy with Cefizox may be initiated pending results of the studies; however, treatment should be adjusted according to study findings. In serious infections, Cefizox has been used

concomitantly with aminoglycosides (see PRECAUTIONS). Before using Cefizox

concomitantly with other antibiotics, the prescribing information for those agents

should be reviewed for contraindications, warnings, precautions, and adverse reactions. Renal function should be carefully monitored.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of Cefizox and other antibacterial drugs, Cefizox 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.


Cefizox (ceftizoxime for injection, USP) is contraindicated in patients who have known allergy to the drug.

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