Intra-Abdominal Infection
- Community-acquired or early hospital acquired including:
- Cholecystitis/ascending cholangitis
- Diverticulitis
- Gangrenous/perforated appendicitis
- Penetrating abdominal trauma
- Post-op peritonitis
- For cases with foreign body or immunosuppression or perforated GI tract or complex cases, discuss with Micro/ID
Treat for 3-7 days (review iv daily). Typically 3-4 days after adequate source control are sufficient for most indications.
Preferred
amoxicillin 1g iv tds AND gentamicin 5mg/kg iv (Gentamicin is for a maximum of 3 days). Take a gentamicin level at 6-14 hours after first dose to calculate dosing interval, usually 24 hourly, 36 hourly or 48 hourly. See gentamicin monograph for dosing (including renal dosing) and monitoring.
If IV antibiotics still needed after 3 days of treatment please contact Micro/ID.
If adequate source control is not feasible or delayed, or anaerobic organism isolated or colorectal source of infection: ADD metronidazole 400mg po tds (or 500mg iv tds only if NBM)
Alternative
For penicillin allergy (non-severe or severe) OR MRSA positive:
co-trimoxazole 960mg po bd (iv only if NBM)
If adequate source control is not feasible or delayed, or anaerobic organism isolated or colorectal source of infection: ADD metronidazole 400mg po tds (or 500mg iv tds only if NBM)
Alternative for penicillin allergy (non-severe):
cefazolin* 2g iv tds AND gentamicin 5mg/kg iv (Gentamicin is for a maximum of 3 days). Take a gentamicin level at 6-14 hours after first dose to calculate dosing interval, usually 24 hourly, 36 hourly or 48 hourly. See gentamicin monograph for dosing (including renal dosing) and monitoring.
*Caution: Prothrombin time, INR and APTT may increase on cefazolin treatment courses, please monitor. For more information see Cefazolin associated coagulation disorders
If adequate source control is not feasible or delayed, or anaerobic organism isolated or colorectal source of infection: ADD metronidazole 400mg po tds (or 500mg iv tds only if NBM)
IV to Oral Switch
Preferred oral switch:
amoxicillin 500mg - 1g po tds (only if positive microbiology cultures and organism known to be sensitive)
OR
cefalexin 1g po qds (increased to 1.5g po qds in severe infection)
OR
co-trimoxazole 960mg po bd
If adequate source control is not feasible or delayed, or anaerobic organism isolated or colorectal source of infection: ADD metronidazole 400mg po tds