Appendicitis Empiric Therapy 

Updated: Jan 14, 2015
Author: Kara E Hennelly, MD; Chief Editor: Thomas E Herchline, MD 

Empiric Therapy Regimens

Preoperative antibiotic prophylaxis should be given in conjunction with surgery for suspected appendicitis. Antibiotics should be stopped after surgery in patients without perforation. In patients with suspected appendicitis who do not undergo surgery, antimicrobial therapy should be administered for at least 3 days, until clinical symptoms and signs of infection resolve.[1, 2, 3, 4, 5] For pediatric ruptured appendicitis, subcutaneous antibiotic powder and intravenous antibiotics can be effective prophylaxis for postoperative intra-abdominal abscess after open appendectomy.[6]

See Appendicitis: Avoiding Pitfalls in Diagnosis, a Critical Images slideshow, to help make an accurate diagnosis.

Acute appendicitis

See the list below:

  • Ampicillin-sulbactam 3 g IV q6h or

  • Piperacillin-tazobactam 3.375-4.5 g IV q6-8h or

  • Ticarcillin-clavulanate 3.1 g q4-6h or

  • Ceftriaxone 1 g IV q24h plusmetronidazole 500 mg IV q8h or

  • Cefuroxime 1.5 g IV q8h plus metronidazole 500 mg IV q8h or

  • Cefazolin 1-2 g IV q8h plus metronidazole 500 mg IV q8h or

  • Ciprofloxacin 400 mg IV q12h plus metronidazole 500 mg IV q8h or

  • Levofloxacin 500 mg IV daily plus metronidazole 500 mg IV q8h or

  • Ertapenem 1 g IV daily

Complicated appendicitis

See the list below:

  • Moxifloxacin 400 mg IV daily or

  • Piperacillin-tazobactam 4.5 g IV q8h or

  • Meropenem 1 g IV q8h or

  • Doripenem 500 mg IV q8h or

  • Levofloxacin 750 mg IV daily plus metronidazole 500 mg IV q8h or

  • Ciprofloxacin 400 mg IV q12h plus metronidazole 500 mg IV q8h or

  • Cefepime 2 g IV q8-12h plus metronidazole 500 mg IV q8h or

  • Ceftolozane/tazobactam 1.5 g IV q8h plus metronidazole 500 mg IV q8h or

  • Aztreonam 1-2 g IV q8h plus metronidazole 500 mg IV q8h or

  • Imipenem/cilastatin 500 mg IV q6h