[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Beta-lactams](https://durgical.com/en/pharmacology/classes/beta-lactams/) › Cefoxitin [Pharmacology](https://durgical.com/en/pharmacology/) · [Beta-lactams](https://durgical.com/en/pharmacology/classes/beta-lactams/) # Cefoxitin A second-generation intravenous cephamycin active against anaerobes such as Bacteroides fragilis; used in mixed abdominal and pelvic infections. Updated 2026-11-01 - Class: [Beta-lactams](https://durgical.com/en/pharmacology/classes/beta-lactams/) - Enzyme: Penicillin-binding proteins (bacterial transpeptidases) - ATC code: J01DC01 ✂**Penicillin-binding proteins (bacterial transpeptidases)**Cefoxitin ⓘ The figure shows E. coli PBP5 (a DD-carboxypeptidase) in an acyl-enzyme complex with cefoxitin. **Target in 3D:** Penicillin-binding proteins (bacterial transpeptidases). PDB structure 3MZE (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/3MZE) · Drag to rotate · pinch to zoom ## Mechanism of action Cefoxitin is a cephamycin, with a methoxy group at position 7 of the core; it is stable to many β-lactamases, including those of Bacteroides fragilis, and more stable than other cephalosporins to ESBLs. It acylates the PBPs and stops wall synthesis. It covers susceptible gram-positive cocci, enteric bacteria and anaerobes, but is less active against H. influenzae and does not cover enterococci or Pseudomonas. - Resists anaerobe β-lactamases - Acylates the PBPs of Bacteroides and enteric bacteria - Peptidoglycan cross-linking stops - The bacterium lyses ## Pharmacokinetics **Absorption** Intravenous only. **Elimination** By the kidney, unchanged; adjusted in kidney failure. **Half-life** Short, 41 to 59 minutes. ## Indications - Intra-abdominal infections such as peritonitis and abscesses due to gram-negatives and anaerobes. [Peritonitis →](https://durgical.com/en/conditions/peritonitis/) - Gynaecological infections, including pelvic inflammatory disease. [Pelvic inflammatory disease →](https://durgical.com/en/conditions/pelvic-inflammatory-disease/) - Mixed anaerobic infections such as diverticulitis. [Diverticular disease and diverticulitis →](https://durgical.com/en/conditions/diverticular-disease-and-diverticulitis/) - Prophylaxis in gastrointestinal surgery, hysterectomy and caesarean section. ## Adverse effects ### Common - Thrombophlebitis at the infusion site - Rash, eosinophilia - Diarrhoea ### Serious (rare, important) - Anaphylaxis - Clostridioides difficile diarrhoea, from mild to severe colitis - Kidney toxicity when combined with aminoglycosides ## Contraindications - Hypersensitivity to cefoxitin or other cephalosporins ## Key interactions **Aminoglycosides** More kidney toxicity; kidney function is monitored. **Probenecid** Reduces tubular secretion: higher and longer-lasting β-lactam levels. **Creatinine measured by the Jaffé method** High cefoxitin levels give falsely raised creatinine; do not draw the sample right after a dose. ## What is monitored - Kidney function (with an unaffected creatinine method) - Infusion site ## Administration and safety - Intravenous, by slow injection or infusion. - For creatinine, time the sample against the dose (false increases). - Do not confuse cefoxitin with cefotaxime or ceftriaxone. ## Nursing care - Before the first dose: ask about allergy to penicillins, cephalosporins and other β-lactams, and what the reaction was. - Rotate and watch the infusion site for thrombophlebitis. - Watch urine output and creatinine, more so with aminoglycosides. - Teach the patient to report watery or bloody diarrhoea, even weeks after the course ends. ## Pregnancy and breastfeeding Animal studies showed no fetal harm and there are no controlled studies in pregnant women; used if clearly needed. ## Memory aid 'Cefoxitin = eXcellent on anaerobes': the cephamycin that reaches Bacteroides fragilis in the abdomen and pelvis. ## Test yourself Think of the answer, then tap the question to see it. ## Which important anaerobe does cefoxitin cover and cefuroxime does not? Bacteroides fragilis; that is why cefoxitin is used for mixed abdominal and pelvic infections. ## Why can cefoxitin distort a creatinine result? At high concentrations it interferes with the Jaffé method and gives false increases. ## In which infections is cefoxitin used because of its spectrum? Mixed aerobic–anaerobic infections such as intra-abdominal and pelvic ones, and prophylaxis for gastrointestinal and gynaecological surgery. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/cefoxitin/) ## Related drugs - [Cefuroxime](https://durgical.com/en/pharmacology/cefuroxime/) - [Cefazolin](https://durgical.com/en/pharmacology/cefazolin/) - [Ampicillin + sulbactam](https://durgical.com/en/pharmacology/ampicillin-sulbactam/) ## Related conditions - [Peritonitis](https://durgical.com/en/conditions/peritonitis/) - [Pelvic inflammatory disease](https://durgical.com/en/conditions/pelvic-inflammatory-disease/) - [Diverticular disease and diverticulitis](https://durgical.com/en/conditions/diverticular-disease-and-diverticulitis/) [← Back to the class: Beta-lactams](https://durgical.com/en/pharmacology/classes/beta-lactams/) Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given. Sources: [Cefoxitin Injection: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a682737.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [DailyMed - CEFOXITIN injection, powder, for solution](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=658a0dc6-6da5-44dc-94f2-1211619297f7) (DailyMed (U.S. National Library of Medicine), 2026); [RCSB PDB - 3MZE: Structure of penicillin-binding protein 5 from E.coli: cefoxitin acyl-enzyme complex](https://www.rcsb.org/structure/3MZE) (RCSB Protein Data Bank, 2026); Farmacología básica y clínica (Katzung), cap. 43 (McGraw Hill, 2025). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/pharmacology/cefoxitin/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/cefoxitin/