Clinical definition:
Intramural inflammation of the gastrointestinal tract extending into the peritoneal space.
| Preferred antibiotic choice(s) | |||
| Drug | Formulation | Dosage | Duration |
| If mild to moderate: | 4 days if source control has been achieved and clinical condition is improving. If not, duration will depend on clinical and radiological progress, jointly managed with surgeons. | ||
| Amoxicillin + clavulanic acid (IV/PO) | Powder for injection: 500 mg (as sodium) + 100 mg (as potassium salt); 1000 mg (as sodium) + 200 mg (as potassium salt) in vial; Oral liquid: 125 mg amoxicillin + 31.25 mg clavulanic acid/5 mL AND 250 mg amoxicillin + 62.5 mg clavulanic acid/5 mL; Tablet: 500 mg (as trihydrate) + 125 mg (as potassium salt) | 875 mg of amoxicillin component 8 hourly | |
| If severe: | |||
| Combination therapy with: Cefotaxime (IV) PLUS Metronidazole (IV) | Cefotaxime- Powder for injection: 250 mg per vial (as sodium salt | 2 g 8 hourly | |
| Metronidazole- Injection: 500 mg in 100- mL vial | 500 mg 6 hourly | ||
| Combination therapy with: Ampicillin (IV) PLUS Gentamicin (IV) PLUS Metronidazole (IV) | Ampicillin- Powder for injection: 500 mg; 1 g (as sodium salt) in vial | 200 mg/kg 4 hourly | |
| Gentamicin- Injection: 10 mg; 40 mg (as sulfate)/ mL in 2- mL vial. | 1 mg/kg 8 hourly | ||
| Metronidazole- Injection: 500 mg in 100- mL vial | 500 mg 6 hourly | ||
| If hospital-acquired in a facility where resistance has been documented, consider: | |||
| Piperacillin-tazobactam | Powder for injection: 2 g (as sodium salt) + 250 mg (as sodium salt); 4 g (as sodium salt) + 500 mg (as sodium salt) in vial | 4.5 g 6 hourly | 4 days if source control has been achieved and clinical condition is improving. If not, duration will depend on clinical and radiological progress, jointly managed with surgeons. |
| Alternative antibiotic choice | |||
| Meropenem | Powder for injection: 500 mg (as trihydrate); 1 g (as trihydrate) in vial | 1 g 8 hourly | 4 days if source control has been achieved and clinical condition is improving. If not, duration will depend on clinical and radiological progress, jointly managed with surgeons. |
| In case of confirmed penicillin allergy or medical contraindication | |||
| Combination therapy with: Clindamycin (IV) PLUS Gentamicin (IV) OR Ciprofloxacin (IV) | Clindamycin- Injection: 150 mg (as phosphate)/mL | 20 mg/kg/day divided every 6 to 8 hours | 4 days if source control has been achieved and clinical condition is improving. If not, duration will depend on clinical and radiological progress, jointly managed with surgeons. |
| Gentamicin- Injection: 10 mg; 40 mg (as sulfate)/ mL in 2- mL vial. | 1 mg/kg 8 hourly | ||
| Ciprofloxacin- Solution for IV infusion: 2 mg/ mL (as hyclate) | 500 mg 12 hourly | ||
Principles of Stewardship:
- Obtain a blood culture prior to starting any new antibiotic therapy.
- Breach of the gastrointestinal tract mucosa is a risk factor for candida infection, which should be considered if source control and antibiotic treatment are not inducing a response.
- Investigate for TB in endemic areas.
Notes:
- cIAI is often a difficult infection to treat and requires close collaboration with surgical colleagues to manage, as source control is a key aspect of management.