What are the prophylaxis drugs for Spontaneous Bacterial Peritonitis (SBP)?

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Last updated: May 14, 2025View editorial policy

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From the Guidelines

Norfloxacin 400 mg once a day is the recommended medication for secondary prophylaxis of spontaneous bacterial peritonitis (SBP) in patients with cirrhosis who have had a previous episode of SBP, as it reduces the probability of recurrence of SBP from 68% to 20% 1. The choice of antibiotic for SBP prophylaxis is crucial in preventing recurrence and improving survival in patients with cirrhosis.

  • The cumulative recurrence rate of SBP at 1 year is approximately 70% in patients who survive an episode of SBP 1.
  • The probability of survival at 1 year after an episode of SBP is 30–50% and falls to 25–30% at 2 years 1.
  • Norfloxacin has been shown to be effective in reducing the probability of recurrence of SBP, with a significant reduction in the probability of SBP due to Gram-negative bacteria (GNB) from 60% to 3% 1.
  • Ciprofloxacin 500 mg once a day can be used as an alternative to norfloxacin, especially in areas where norfloxacin is not readily available 1.
  • Regular monitoring for side effects and development of bacterial resistance is recommended during long-term prophylaxis.
  • The use of proton pump inhibitors may increase the risk for the development of SBP, and indications for long-term use should be carefully assessed 1.

From the FDA Drug Label

For the prophylaxis in adults is 1 sulfamethoxazole and trimethoprim DS (double strength) tablet daily For children, the recommended dose is 750 mg/m2/day sulfamethoxazole with 150 mg/m2/day trimethoprim given orally in equally divided doses twice a day, on 3 consecutive days per week.

The recommended SBP prophylaxis drug is trimethoprim-sulfamethoxazole.

  • For adults, the dosage is 1 DS tablet daily.
  • For children, the dosage is 750 mg/m2/day sulfamethoxazole with 150 mg/m2/day trimethoprim, given orally in equally divided doses twice a day, on 3 consecutive days per week 2.

From the Research

Spontaneous Bacterial Peritonitis Prophylaxis Drugs

The following drugs are used for the prophylaxis of spontaneous bacterial peritonitis (SBP):

  • Norfloxacin: a fluoroquinolone antibiotic that has been widely used for the prevention of SBP in patients with cirrhosis and ascites 3, 4, 5, 6, 7
  • Ciprofloxacin: another fluoroquinolone antibiotic that has been shown to be effective in the prevention of SBP 3, 7
  • Trimethoprim-sulfamethoxazole: a combination antibiotic that has been used as an alternative to norfloxacin for the prevention of SBP 3, 5, 7
  • Rifaximin: a rifamycin antibiotic that has been shown to be effective in the prevention of SBP, particularly in patients with a history of SBP 3, 4, 7

Comparison of Prophylaxis Drugs

Studies have compared the efficacy of these drugs in the prevention of SBP:

  • Norfloxacin and ciprofloxacin have been shown to be effective in the prevention of SBP, with similar efficacy 3
  • Trimethoprim-sulfamethoxazole has been shown to be equally effective as norfloxacin in the prevention of SBP, but with a higher risk of adverse events 5
  • Rifaximin has been shown to be more effective than norfloxacin in the prevention of SBP, particularly in patients with a history of SBP 4, 7

Recommendations

Based on the available evidence, the following recommendations can be made:

  • Norfloxacin is a commonly used drug for the prevention of SBP, but rifaximin may be a better option for patients with a history of SBP 4, 7
  • Ciprofloxacin and trimethoprim-sulfamethoxazole are alternative options for the prevention of SBP, but may have different efficacy and safety profiles compared to norfloxacin and rifaximin 3, 5, 7

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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