Norfloxacin Versus Ciprofloxacin for Spontaneous Bacterial Peritonitis (SBP) Prevention

* For the prevention of spontaneous bacterial peritonitis (SBP) in patients with liver cirrhosis, norfloxacin 400mg per day is a standard regimen. * Ciprofloxacin 750 mg per week is also known to be effective for prevention of SBP. In addition, ciprofloxacin once weekly administration is more convenient and less costly. * Therefore ciprofloxacin once weekly could be more useful if the the efficacy is comparable to norfloxacin once daily. * This study aims to prove ciprofloxacin once weekly administration is as effective as norfloxacin once daily administration for the prevention of SBP in cirrhotic patients with ascites.