3rd-generation cephalosporin:
Cefotaxime 2g IV q8hr or Ceftriaxone 1-2g IV q12-24hr
If beta-lactam allergy, ciprofloxacin 400mg IV q12hr
If peritoneal dialysis: vancomycin and cefepime 
Cefotaxime 2g IV q8hr or Ceftriaxone 1-2g IV q12-24hr
Reduces renal failure and hospital mortality if given within 6 hours
Give for all or (larger effect) if creatinine >1mg/dL, BUN >30mg/dL, or T Bili >4mg/dL
1.5gm/kg at within 6 hrs of diagnosis; 1gm/kg on day 3
Spontaneous bacterial peritonitis
Abdominal aortic aneurysm
Peritoneal dialysis-associated peritonitis
Aortocaval fistula
Large bowel obstruction
Acute gastroenteritis
Malignant bowel obstruction
Aortoenteric fisulta