From the Guidelines

Yes, oral antibiotics can be used to treat Spontaneous Bacterial Peritonitis (SBP) in certain cases.

Oral ofloxacin has been shown to have similar results to intravenous cefotaxime in uncomplicated SBP, without renal failure, hepatic encephalopathy, gastrointestinal bleeding, ileus, or shock 1.
Amoxicillin/clavulanic acid, first given intravenously then orally, has similar results with respect to SBP resolution and mortality as cefotaxime, but with a much lower cost 1.
However, the use of oral antibiotics should be cautious, especially in areas with high prevalence of quinolone-resistant bacteria or in nosocomial SBP 1.
The choice of antibiotics should be made taking into account the possibility of infection by quinolone-resistant strains, especially in patients who have previously recovered from SBP and in those who have been exposed to quinolone 1.

Third-generation cephalosporins, such as cefotaxime, are recommended as first-line antibiotic treatment for SBP 1.
Alternative options include amoxycillin/clavulanic acid and quinolones such as ciprofloxacin or ofloxacin 1.
The standard treatment duration is 5 to 10 days, but should vary according to the symptoms and/or results of antimicrobial susceptibility testing 1.

From the Research

The treatment of SBP typically involves the use of non-nephrotoxic broad-spectrum antibiotics expected to cover the typical bacterial flora associated with SBP 2.
Third-generation, broad-spectrum cephalosporins remain a good initial choice for SBP treatment, with cefotaxime being a commonly used option 2, 3.
Oral antibiotics, such as norfloxacin, can be used as prophylaxis to prevent SBP in high-risk patients, including those with low-protein ascites or a history of SBP 2, 4.
For uncomplicated SBP, early oral switch therapy is reasonable, with options including levofloxacin or other oral fluoroquinolones 3.
The efficacy of empirical antibiotics, such as cefotaxime, ceftriaxone, and ciprofloxacin, against SBP was not significantly different in a randomized trial 5.

Oral antibiotic prophylaxis has been shown to reduce the occurrence of SBP and improve short-term survival in cirrhotic patients with ascites 4.
A meta-analysis found that oral antibiotic therapy provides a survival benefit for patients with advanced cirrhosis and ascites, with a reduced risk of all infections, including SBP 4.
However, the optimal dose and duration of oral antibiotic therapy for SBP treatment are not well established, and more research is needed to determine the best approach 6.

The increasing rate of antibiotic resistance is a concern in the treatment of SBP, and alternative antibiotic regimens may be necessary for patients with nosocomial SBP or those who fail to improve on traditional antibiotic regimens 3, 5.
The use of oral antibiotics, such as norfloxacin, as prophylaxis may contribute to the development of antibiotic resistance, and their use should be carefully considered and monitored 2, 4.