rifaximin + norfloxacin

The combination of rifaximin and norfloxacin is primarily used for the prevention of spontaneous bacterial peritonitis (SBP) in patients with liver cirrhosis and ascites. Clinical studies have shown that this combination therapy offers promising results compared to monotherapy with either drug alone. Rifaximin is a non-systemic antibiotic targeting the gastrointestinal tract. Its mechanism involves inhibiting bacterial RNA synthesis by binding to the beta-subunit of bacterial DNA-dependent RNA polymerase enzyme, thereby blocking translocation and stopping transcription. Norfloxacin is a fluoroquinolone antibiotic traditionally used for SBP prophylaxis. Studies have investigated an alternating regimen where patients receive rifaximin (1100-1200 mg/day, typically divided) for one month, followed by norfloxacin (400 mg/day) for one month. This alternating approach demonstrated a superior efficacy rate of 74.7% in preventing SBP compared to 56.4% for norfloxacin alone and 68.3% for rifaximin alone in intention-to-treat analysis. The combination therapy has shown a safety profile similar to monotherapy, despite known interaction profiles for each drug individually. Recent clinical studies continue to evaluate the efficacy of this combination for the primary prevention of SBP.