From the Guidelines
The best prophylaxis for spontaneous bacterial peritonitis (SBP) is norfloxacin 400 mg orally once daily, as recommended by the most recent guidelines 1. Alternative options include ciprofloxacin 500 mg orally once daily or trimethoprim-sulfamethoxazole (TMP-SMX) one double-strength tablet orally daily.
Key Points
- SBP prophylaxis should be given to cirrhotic patients with a prior history of SBP, those with ascitic fluid protein less than 1.5 g/dL, or patients with acute gastrointestinal bleeding.
- For patients with gastrointestinal bleeding, a short course of prophylaxis (7 days) with ceftriaxone 1 g IV daily is preferred.
- SBP prophylaxis works by suppressing gut bacterial flora, particularly gram-negative organisms, which are the most common causative pathogens.
- Prophylaxis significantly reduces SBP recurrence rates from approximately 70% to 20% within one year and improves survival in high-risk patients, as shown in a study published in 2021 1.
- Antibiotic resistance should be monitored, and prophylaxis should be continued indefinitely in patients with ongoing risk factors, particularly those awaiting liver transplantation.
Rationale
The rationale for choosing norfloxacin as the best prophylaxis for SBP is based on its effectiveness in reducing SBP recurrence rates and improving survival in high-risk patients, as demonstrated in several studies, including a randomized, double-blind, placebo-controlled trial published in 2021 1. Additionally, norfloxacin has been shown to be effective in preventing SBP in patients with low ascitic fluid protein concentration and advanced liver failure 1.
Considerations
When considering SBP prophylaxis, it is essential to weigh the potential benefits and risks, including the development of antibiotic resistance, as noted in a study published in 2010 1. Furthermore, the choice of antibiotic should be guided by local resistance patterns and protocols, as recommended by the guidelines 1.
Summary of Evidence
The evidence supporting the use of norfloxacin as the best prophylaxis for SBP includes:
- A randomized, double-blind, placebo-controlled trial published in 2021 1 demonstrating the effectiveness of norfloxacin in reducing SBP recurrence rates and improving survival in high-risk patients.
- A study published in 2010 1 showing the effectiveness of norfloxacin in preventing SBP in patients with low ascitic fluid protein concentration and advanced liver failure.
- Guidelines published in 2021 1 recommending norfloxacin as the first-line prophylaxis for SBP in high-risk patients.
From the Research
Prophylaxis for Spontaneous Bacterial Peritonitis (SBP)
The best prophylaxis for SBP is a topic of ongoing research, with various studies investigating the efficacy of different antibiotics.
- Norfloxacin is a commonly used prophylactic antibiotic for the prevention of SBP in patients with cirrhosis and ascites 2, 3.
- Rifaximin has been shown to be effective in the secondary prophylaxis of SBP, with a significant decrease in adverse events and mortality rate compared to norfloxacin 2, 4.
- A network meta-analysis found that rifaximin ranked first in terms of preventing SBP and mortality in patients with cirrhosis and ascites, compared to norfloxacin, ciprofloxacin, and trimethoprim-sulfamethoxazole 5.
- The choice of prophylactic antibiotic may depend on various factors, including the patient's underlying condition, the presence of risk factors, and the potential for antibiotic resistance 3, 6.
Comparison of Prophylactic Antibiotics
The following antibiotics have been studied as potential prophylactic options for SBP:
- Norfloxacin: effective in primary and secondary prophylaxis, but may be associated with an increased risk of adverse events 2, 3.
- Rifaximin: effective in secondary prophylaxis, with a significant decrease in adverse events and mortality rate compared to norfloxacin 2, 4.
- Ciprofloxacin: may be effective in primary prophylaxis, but its efficacy in secondary prophylaxis is unclear 2, 5.
- Trimethoprim-sulfamethoxazole: may be effective in primary and secondary prophylaxis, but its use is limited by the potential for adverse events and antibiotic resistance 2, 5.