• Type: Second generation cephalosporin
  • Dosage Forms: powder for injection
  • Dosage Strengths: 1g, 2g, 10g
  • Route of Administration: IV
  • Common Trade Names: Mefoxin

Adult Dosing

  • 1-2g IV q6-8h

Pediatric Dosing

  • <3 months old: Safety & efficacy not established
  • >3 months old: 80-160 mg/kg/day IV divided q4-6hr; higher dosages should be used for more severe or serious infections

Special Populations

  • Pregnancy: Category B
  • Lactation: Minimal excretion in breast milk, limited data on affect to infant
  • Renal Dosing
    • CrCl 30-50 mL/min: 1-2 g q8-12hr
    • CrCl 10-30 mL/min: 1-2 g q12-24hr
    • CrCl 5-9 mL/min: 500 mg-1 g q24-28hr
    • CrCl <5 mL/min: 500 mg-1 g q24-48hr
  • Hepatic Dosing: not defined


  • Allergy to class/drug
  • Neonates

Adverse Reactions



  • Diarrhea
  • Anemia, thrombocytopenia, transient leukopenia
  • Elevated Cr/BUN
  • Elevated LFTs


  • Half-life: 45-60 min
  • Metabolism:
  • Excretion: Unchanged in urine (85%)
  • Mechanism of Action: Inhibits bacterial cell wall synthesis

Antibiotic Sensitivities[1]

Group Organism Sensitivity
Gram Positive Strep. Group A, B, C, G S
Strep. Pneumoniae S
Viridans strep S
Strep. anginosus gp X1
Enterococcus faecalis R
Enterococcus faecium X1
Staph. Epidermidis I
C. jeikeium R
L. monocytogenes R
Gram Negatives N. gonorrhoeae I
N. meningitidis I
Moraxella catarrhalis S
H. influenzae S
E. coli S
Klebsiella sp S
E. coli/Klebsiella ESBL+ R
E coli/Klebsiella KPC+ R
Enterobacter sp, AmpC neg R
Enterobacter sp, AmpC pos R
Serratia sp R
Serratia marcescens X1
Salmonella sp X1
Shigella sp X1
Proteus mirabilis S
Proteus vulgaris S
Providencia sp. S
Morganella sp. S
Citrobacter freundii R
Citrobacter diversus I
Citrobacter sp. I
Aeromonas sp I
Acinetobacter sp. R
Pseudomonas aeruginosa R
Burkholderia cepacia R
Stenotrophomonas maltophilia R
Yersinia enterocolitica I
Francisella tularensis X1
Brucella sp. X1
Legionella sp. R
Pasteurella multocida X1
Haemophilus ducreyi S
Vibrio vulnificus X1
Misc Chlamydophila sp X1
Mycoplasm pneumoniae X1
Rickettsia sp X1
Mycobacterium avium X1
Anaerobes Actinomyces X1
Bacteroides fragilis S
Prevotella melaninogenica S
Clostridium difficile R
Clostridium (not difficile) S
Fusobacterium necrophorum S
Peptostreptococcus sp. S


  • S susceptible/sensitive (usually)
  • I intermediate (variably susceptible/resistant)
  • R resistant (or not effective clinically)
  • S+ synergistic with cell wall antibiotics
  • U sensitive for UTI only (non systemic infection)
  • X1 no data
  • X2 active in vitro, but not used clinically
  • X3 active in vitro, but not clinically effective for Group A strep pharyngitis or infections due to E. faecalis
  • X4 active in vitro, but not clinically effective for strep pneumonia

See Also


  1. Sanford Guide to Antimicrobial Therapy 2014