What is the recommended pre‑operative medication regimen for a standard, uncomplicated appendectomy?

Preoperative Antibiotic Prophylaxis for Uncomplicated Appendectomy

Administer a single dose of broad-spectrum antibiotics 0-60 minutes before surgical incision, with no postoperative antibiotics needed for uncomplicated appendicitis. 1

Recommended Antibiotic Regimens

For standard uncomplicated appendicitis, use one of the following single preoperative doses:

• Cefazolin 1-2 grams IV (first-line choice for most patients) 2
• Cefoxitin 2 grams IV (alternative first-generation option) 3
• Piperacillin-tazobactam 3.375 grams IV (broader spectrum, though narrower agents are equally effective) 3

For patients with beta-lactam allergy:

• Moxifloxacin 400 mg IV combined with metronidazole 4
• Ciprofloxacin plus metronidazole 3

Critical Timing Window

Administer antibiotics within 0-60 minutes before the surgical skin incision to ensure adequate tissue levels at the moment of bacterial exposure. 1 This timing window is supported by high-quality evidence from Cochrane meta-analyses including over 9,000 patients, demonstrating significant reductions in both wound infections and intra-abdominal abscesses. 1

What NOT to Do: Common Pitfalls

Do not continue antibiotics postoperatively for uncomplicated appendicitis. 1, 5 This is a strong recommendation (Grade 1A) based on high-quality evidence. Recent studies actually show an association between postoperative antibiotic use and increased wound infection rates in uncomplicated cases (odds ratio 6.53). 6

Avoid ampicillin-sulbactam due to E. coli resistance rates exceeding 20%. 3

Do not use extended-spectrum agents routinely when narrower-spectrum antibiotics are adequate—a quality improvement study successfully reduced piperacillin-tazobactam use from 51% to 20% without increasing surgical site infection rates. 7

Evidence Supporting Single-Dose Approach

The World Journal of Emergency Surgery guidelines (2020) provide the strongest evidence base, synthesizing multiple Cochrane reviews and randomized trials. 1 The key finding: a single preoperative dose is as effective as prolonged courses for preventing surgical site infections in uncomplicated appendicitis, with no benefit from postoperative continuation. 1, 5

Even when patients receive broad-spectrum antibiotics in the emergency department before surgery, additional pre-incisional cefazolin does not further reduce infection rates. 8 However, the emergency department antibiotics themselves do provide benefit when given before surgery. 8

Special Considerations

For patients already receiving treatment antibiotics in the emergency department: The broad-spectrum coverage already administered provides adequate prophylaxis, and additional pre-incisional cefazolin offers no incremental benefit. 8 However, ensure the emergency department antibiotics were given within the appropriate timeframe relative to incision.

Pediatric dosing: Use 25-50 mg/kg/day of cefazolin for most infections, with a single preoperative dose of cefoxitin or cefotetan being appropriate for non-perforated appendicitis. 5, 2

When Postoperative Antibiotics ARE Indicated

Only continue antibiotics postoperatively if:

• Complicated appendicitis (perforation, abscess, or gangrenous with established peritonitis) is found at surgery 1, 5
• Inadequate source control was achieved during the operation 1

For complicated cases with adequate source control, limit postoperative antibiotics to 24 hours or maximum 3-5 days. 5, 3 Prolonged courses beyond 5 days provide no additional benefit and increase antibiotic resistance. 1