cefoxitin
Brand: Mefoxin
Prototype: cefuroxime
Drug Class: second-generation cephalosporin (cephamycin)
Drug Family: antibiotic
Subclass: parenteral cephamycin
Organ Systems: infectious-disease
Mechanism of Action
Inhibits cell wall synthesis; as a cephamycin, has enhanced beta-lactamase stability and excellent anaerobic coverage (Bacteroides fragilis), distinguishing it from other second-generation cephalosporins.
penicillin-binding proteins (PBPs)
Indications
- intra-abdominal infections
- pelvic inflammatory disease
- gynecological infections
- surgical prophylaxis (colorectal)
- anaerobic infections
Contraindications
- cephalosporin hypersensitivity
Adverse Effects
Common
- injection site reactions
- diarrhea
- elevated LFTs
Serious
- anaphylaxis
- C. difficile colitis
- disulfiram-like reaction (rare)
Pharmacokinetics (ADME)
| Absorption | IV/IM only |
| Distribution | widely distributed including peritoneal fluid; poor CSF penetration |
| Metabolism | minimal hepatic |
| Excretion | renal (85% unchanged within 6 hours) |
| Half-life | 0.7–1.1 hours |
| Onset | immediate (IV) |
| Peak | 20–30 min (IM) |
| Duration | 6–8 hours |
| Protein Binding | 65–79% |
| Vd | low-moderate |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| probenecid | reduces renal excretion | minor |
| aminoglycosides | potential additive nephrotoxicity | moderate |
Nursing Considerations
- Administer IV over 3–5 minutes (IV push) or 15–30 minutes (IV infusion); reconstitute per manufacturer instructions.
- Monitor renal function and urine output, particularly when used with other nephrotoxic agents.
- For surgical prophylaxis, administer 1–2 g IV within 30–60 minutes before incision; may redose if procedure extends beyond 2 hours.
- Assess for cephalosporin allergy and document cross-reactivity history with penicillin.
Clinical Pearls
- Cefoxitin is one of the few beta-lactams with reliable anaerobic coverage including Bacteroides fragilis, making it valuable for gynecological and intra-abdominal prophylaxis.
- As a cephamycin, it has a 7-alpha-methoxy group that confers enhanced stability against many beta-lactamases.
Safety Profile
Pregnancy generally-safe
Lactation use-with-caution
Renal Adjustment Required
Hepatic Adjustment Not required
TDM Not required
Concordance Terms
Cross-referenced clinical concepts — click any term to see all content where it appears.