Cefoxitin (PDF Version)

Antibiotic Class:

Second-Generation Cephalosporin (2^nd generation cephamycin)

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 Ò/Merck, Cefoxitin Ò/ESI Lederle