Cefoxitin  (PDF Version)

Antibiotic Class:

Second-Generation Cephalosporin (2nd generation cephamycin)

Antimicrobial Spectrum:

Staphylococcus aureus (methicillin susceptible), Coagulase negative Staphylococci, Streptococcus pneumoniae (penicillin susceptible), Streptococcus spp, Haemophilus influenzae, Moraxella catarrhalis, Neisseria meningitides, Neisseria gonorrhoeae, Enterobacteriaceae, E. coli Bacteroides spp.

Mechanism of Action:

Cephalosporins exert bactericidal activity by interfering with bacterial cell wall synthesis and inhibiting cross-linking of the peptidoglycan. The cephalosporins are also thought to play a role in the activation of bacterical cell autolysins which may contribute to bacterial cell lysis.

Pharmacodynamics

Cephalosporins exhibit time-dependent killing (T > MIC)

Pharmacokinetics:

Dose of 1g: Cmax: 64 mcg/L; Protein binding: 73%; Half-life: 0.7 hours

Table 11

Adverse Effects:

Hypersensitivity: Maculopapular rash, Urticaria, Pruritis, Anaphylaxis/angioedema, eosinophilia

Hematologic: Hypoprothrombinemia, Neutropenia, Leukopenia, Thrombocytopenia

GI: Diarrhea, C. difficile disease

Renal: Interstitial nephritis

Table 14

Dosage:

I.V.: Vials for reconstitution 1g, 2g

Adults:

Susceptible infections: 1-2g I.V. q6-8h. Doses may be given by painful intramuscular injection

Pediatrics:

80-160mg/kg/day divided in q4-q6h intervals

See Table 12

Disease state based dosing:

Renal failure:              CrCl > 50mL/min: Standard dose

                                 CrCl 30-50mL/min: 1-2g q8-12

                                 CrCl 10-29mL/min: 1-2g q12-24h

                                 CrCl < 10mL/min: q24-48h

Hepatic failure:  No dosing changes recommended at this time.

Contraindications/Warnings/Precautions:

Contraindications: Hypersensitivity to cephalosporins

Precautions: hypersensitivity to penicillins, history of gastrointestinal disease, particularly colitis, renal impairment

Drug Interactions:

Aminoglycosides - loss of aminoglycoside efficacy

Live Typhoid Vaccine - decreased immunological response to the typhoid vaccine

Pregnancy:

Category B: No evidence of risk in humans but studies inadequate.

Monitoring Requirements:

Therapeutic:  Culture and sensitivities, signs and symptoms of infection (eg fever), WBC

Toxic:  Urinalysis, BUN, SCr, AST and ALT, skin rash, Neutropenia and leukopenia, Prothrombin time in 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.

Brand names/Manufacturer: 

Mefoxin /Merck, Cefoxitin /ESI Lederle