The third-generation cephalosporin antibiotics ceftriaxone and cefotaxime are widely used for prophylaxis in abdominal surgery. Both are active against a wide range of gram-positive and gram-negative organisms and have few side effects. The agents differ in cost and pharmacologic properties; 1 g of intravenous ceftriaxone has an average wholesale price of $46 compared with $12 for 1 g of intravenous cefotaxime. Woodfield and colleagues compared the prophylactic efficacy of these agents in more than 1,000 patients undergoing abdominal surgery.

They studied 1,013 adult patients admitted to a general surgery unit in New Zealand for acute or elective abdominal surgery. The patients were randomly assigned to prophylaxis with either agent after stratification to ensure that patients with particularly high risk of infection (e.g., colorectal resections) were equally distributed in both treatment groups. All patients received 1 g of the test agent intravenously at the induction of anesthesia, and patients in the highest risk group also were given 500 mg of metronidazole intravenously. Surgeons and staff did not know the patients' treatment allocations. Patients were followed for at least 30 days after surgery. The major outcome measured was wound infection with pus formation or cellulitis, and minor end points were yeast super-infection, deep peritoneal infection, chest infection, urinary tract infection, intravenous line sepsis, and other infections such as septicemia, infection of drain sites, and diarrhea resulting from Clostridium difficile.

Ninety-three patients were excluded from analysis because of death or a need for antibiotic therapy within 30 days of surgery without a wound infection. The 462 patients treated with ceftriaxone were comparable to the 458 patients treated with cefotaxime, except that cefotaxime was used slightly more frequently in urgent surgeries such as appendectomies. The overall wound infection rate was 8 percent for ceftriaxone compared with 12 percent for cefotaxime, but after adjustment for appendectomies performed without metronidazole coverage, the wound infection rates were similar (see accompanying table). The number of patients with chest or urinary tract infections was reduced significantly in the ceftriaxone group (6 percent compared with 11 percent in the cefotaxime group), and the percentage of patients who developed any infection also was reduced significantly with ceftriaxone (20 percent compared with 27 percent).

The authors conclude that ceftriaxone and cefotaxime provide effective prophylaxis for abdominal surgeries, but that cefotaxime does not provide adequate coverage for appendectomy without the addition of metronidazole. Overall, ceftriaxone was more effective, particularly againstStaphylococcus aureus, and has a longer half-life and no active metabolites. Despite being more expensive, this agent may be a more versatile choice for antibiotic prophylaxis in abdominal surgery.