Spontaneous Bacterial Peritonitis (SBP) (Antimicrobial)
TAM (Treatments and Medicines) NHS Highland
For glossary of terms see Glossary.
The diagnosis of SPB is based on ascitic fluid neutrophil count >250 cells/mm3 or >0.25 x109/L. Ascitic fluid should be sent for culture and blood cultures performed at the same time, before starting antibiotics, in patients admitted to hospital.
Avoid nephrotoxic antibiotics such as aminoglycosides as empiric therapy.
If no improvement is seen within 48 hours, consider contacting Microbiology for escalation advice.
In all patients with suspected SBP, proton pump inhibitors should only be prescribed for a clear indication.
Patients currently prescribed rifaximin do not require a second antibiotic for primary prophylaxis of SBP in the absence of a GI bleed.
Before prescribing ciprofloxacin, see warnings in the BNF and MHRA Drug Safety Alert (updated 22 January 2024) and which details new and previously published risks with all fluoroquinolones.
Drug details
Community-acquired infection, suitable for out-patient treatment
Oral co-amoxiclav 625mg three times daily
5 to 7 days
If penicillin allergy
Oral ciprofloxacin 750mg twice daily (see BNF warnings and MHRA Drug Safety Alert (updated 22 January 2024))
5 to 7 days
Community-acquired infection requiring hospital admission
IV ceftriaxone 2g once daily
5 to 7 days
Contact Microbiology if known beta-lactam anaphylaxis
If more than 2 courses of antibiotic treatment have been prescribed in the last 2 months (for any indication)
IV piperacillin/tazobactam 4·5g every 6 hours (3 hour infusion time per dose if in critical care)
5 to 7 days
In penicillin allergy
IV aztreonam 2g every 6 hours
PLUS IV Vancomycin as per NHS Highland vancomycin policy
5 to 7 days
If known previous ESBL infection (check SCI Store)
IV meropenem 1g every 8 hours
5 to 7 days
In patients with previous multiple courses of antibiotics, consider fungal pathogens. Contact Microbiology for advice
Switch to targeted therapy based on positive cultures. Review IV therapy daily and consider IV to oral switch with clinical improvement.
For primary prophylaxis in patients with cirrhosis and low ascitic protein content of less than 10g/l
Oral co-trimoxazole 480mg once daily
12 months
If hyperkalaemia develops or on concurrent spirololactone
Oral ciprofloxacin 500mg once daily (see BNF warnings and MHRA Drug Safety Alert (updated 22 January 2024))
12 months
Additional antibiotic prophylaxis is not required for patients on rifaximin.
Prophylaxis should be stopped in patients with lasting clinical improvement and disappearance of ascites.
For primary prophylaxis following upper GI bleed in presence of cirrhosis
Switch from IV to oral once oral route established
If Nil by Mouth
IV ciprofloxacin 400mg every 8 hours (see BNF warnings and MHRA Drug Safety Alert (updated 22 January 2024))
OR oral ciprofloxacin 750mg twice daily (see BNF warnings and MHRA Drug Safety Alert (updated 22 January 2024))
5 days total (IV + oral)
For secondary prophylaxis after episode of SBP
Oral ciprofloxacin 500mg once daily (see BNF warnings and MHRA Drug Safety Alert (updated 22 January 2024))
Lifelong or until resolution of ascites or successful liver transplant