Cefoxitin

Cefoxitin is a cephamycin antibiotic in the cephalosporin class. It is a beta-lactam antimicrobial with activity against many Gram-negative and anaerobic bacteria. Administered by intramuscular or intravenous injection, cefoxitin is often used for surgical prophylaxis and for the treatment of certain intra-abdominal and gynecologic infections.

Mechanism and spectrum: Like other beta-lactams, cefoxitin inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins, leading to bacterial lysis. It has relatively broad activity against Enterobacteriaceae (eg, E. coli, Klebsiella, Proteus) and anaerobes such as Bacteroides fragilis, while showing limited activity against streptococci and staphylococci and generally poor activity against Enterococcus and Pseudomonas aeruginosa.

Clinical use: Cefoxitin is commonly used for colorectal surgery prophylaxis and for treatment of intra-abdominal and gynecologic infections caused by susceptible organisms. It is not reliable for MRSA or Pseudomonas infections. Dosing is typically 1-2 g IV every 6-8 hours, with a higher single preoperative dose for surgical prophylaxis.

Pharmacokinetics and cautions: Cefoxitin is administered parenterally and is largely excreted by the kidneys, requiring dose adjustment in renal impairment. The drug distributes into body fluids and tissues; the half-life is relatively short in patients with normal renal function.

Adverse effects and safety: Common adverse effects include hypersensitivity reactions, rash, diarrhea, and colitis. As with other beta-lactams, severe allergic reactions are possible. Caution is advised in patients with a history of beta-lactam allergy and in those taking nephrotoxic drugs.