What is the appropriate dosing for Cefoxitin (Cephamycin antibiotic)?

From the Guidelines

Cefoxitin should be dosed at 2 g every 6 hours for adults with normal renal function, as recommended by the most recent and highest quality study 1. This dosing regimen is specifically outlined in the guidelines for the diagnosis and management of complicated intra-abdominal infection in adults and children, published in the Clinical Infectious Diseases journal 1.

Key Considerations

• The dosage is based on normal renal and hepatic function, and adjustments may be necessary for patients with renal impairment.
• Cefoxitin is a second-generation cephalosporin with enhanced activity against anaerobes and beta-lactamase producing organisms, making it particularly useful for intra-abdominal, pelvic, and mixed aerobic/anaerobic infections.
• Common side effects include diarrhea, nausea, and potential for hypersensitivity reactions, especially in patients with penicillin allergies.

Dosing Adjustments

• For patients with renal impairment, the following adjustments can be made:
  • Creatinine clearance 30-50 mL/min: 1-2 grams every 8-12 hours
  • Creatinine clearance 10-29 mL/min: 1-2 grams every 12-24 hours
  • Creatinine clearance <10 mL/min: 1-2 grams every 24-48 hours

Pediatric Dosing

• The recommended pediatric dosing is 80-160 mg/kg/day divided every 4-6 hours, not exceeding adult doses. It's worth noting that while other studies 1 also recommend cefoxitin dosing, the most recent and highest quality study 1 provides the most up-to-date and reliable guidance on this topic.

From the FDA Drug Label

An initial loading dose of 1 gram to 2 grams may be given. After a loading dose, the recommendations for maintenance dosage (Table 2) may be used as a guide The recommended dosage in pediatric patients three months of age and older is 80 to 160 mg/kg of body weight per day divided into four to six equal doses. Table 1. Guidelines for Dosage of Cefoxitin for Injection Type of InfectionDaily DosageFrequency and Route Uncomplicated forms* of infections such as pneumonia, urinary tract infection, cutaneous infection3 to 4 grams1 gram every 6 to 8 hours I.V. Moderately severe or severe infections6 to 8 grams1 gram every 4 hours or 2 grams every 6 to 8 hours I. V. Infections commonly needing antibiotics in higher dosage (e.g., gas gangrene)12 grams2 grams every 4 hours or 3 grams every 6 hours I. V. Table 2 Maintenance Dosage of Cefoxitin for Injection in Adults with Reduced Renal Function Renal FunctionCreatinineClearance(mL/min)Dose(grams)Frequency Mild impairment50 to 301 to 2Every 8 to 12 hours Moderate impairment29 to 109 to 5Every 12 to 24 hours Severe impairment9 to 5<51 to 2Every 12 to 24 hours Essentially no function<51 to 1Every 24 to 48 hours

The dosing of Cefoxitin depends on the type of infection and the patient's renal function.

• For uncomplicated infections, the recommended dose is 3 to 4 grams per day, divided into 1 gram every 6 to 8 hours intravenously.
• For moderately severe or severe infections, the recommended dose is 6 to 8 grams per day, divided into 1 gram every 4 hours or 2 grams every 6 to 8 hours intravenously.
• For infections needing higher dosage, the recommended dose is 12 grams per day, divided into 2 grams every 4 hours or 3 grams every 6 hours intravenously.
• For pediatric patients, the recommended dose is 80 to 160 mg/kg of body weight per day, divided into four to six equal doses.
• For patients with renal impairment, the dose and frequency should be adjusted according to Table 2. 2

From the Research

Cefoxitin Dosing

• Cefoxitin is a beta-lactam antibiotic with a broad spectrum of antibacterial activity, including anaerobic and Gram-positive and Gram-negative aerobic bacteria 3.
• The dose of cefoxitin should be reduced in patients with renal functional impairment 4.
• Cefoxitin can be administered by intravenous or intramuscular injection, and is effective against a wide variety of infections caused by Gram-positive or Gram-negative aerobes as well as by anaerobic bacteria 3.
• In the treatment of intra-abdominal infections, cefoxitin can be administered at a dose of 1 to 2 grams every 6 hours 5.
• Cefoxitin should be used with caution in combination with aminoglycoside antibiotics, as it may increase the risk of renal failure 4.

Pharmacokinetics and Elimination

• Cefoxitin is well absorbed after intramuscular injection and produces serum concentrations adequate to treat most infections 6.
• The primary route of elimination is renal, and each agent requires dosage adjustments in patients with renal impairment 6.
• The elimination half-life of cefoxitin is not specified in the provided studies, but it is noted that major differences exist among the elimination half-lives of cephalosporins with enhanced antianaerobic activity in patients with normal renal function 6.

Clinical Efficacy

• Cefoxitin has been shown to be effective in the treatment of intra-abdominal infections, with a clinical response rate of 95% in one study 5.
• Cefoxitin is also effective in the treatment of female genital tract infections and soft-tissue infections, and can be used for prophylactic use in surgical procedures that may involve enteric anaerobes 6.
• Cefoxitin has been compared to other cephalosporins, such as cefotetan, and has been shown to be equally effective in the treatment of intra-abdominal infections 5.