Complicated intra-abdominal infection

The infection breaks out of a hollow organ: gut contents reach the peritoneal cavity through perforation, anastomotic leak, gangrenous appendicitis or cholecystitis. The flora is mixed, with enteric gram-negative rods and anaerobes. Treatment rests on two pillars: source control (surgery or drainage) and a broad-spectrum antibiotic. Antibacterial therapy alone, with the source left in place, does not work.

ICD-10 K65.01 drug

Also known as: Secondary peritonitis, Intra-abdominal abscess

Drugs used for this condition

AMeropenemFirst line · Carbapenem antibiotic for intravenous useComplicated intra-abdominal infection is listed outright among the indications in the AEMPS Archifar label. The reasoning sits in the spectrum: with perforation or an anastomotic leak the peritoneal cavity receives mixed flora, and meropenem covers enteric gram-negative rods together with anaerobes in a single drug, with no metronidazole added. This is not first-line for every appendicitis: the carbapenem is chosen for hospital-acquired infection, recent antibacterial therapy, severe illness or known carriage of resistant flora. The antibiotic does not replace source control – without surgery or drainage it does not rescue. Course length is counted from the day of adequate drainage, not from the first dose.

How to read tiers A–F

Evidence tiers belong to the drug-indication pair, not to the drug as a whole: the same substance can be A for one condition and F for another.

AStrong evidence – first or second line in international guidelines
BRecommended in selected cases
CStudy data contradict each other
DBenefit not proven, no documented harm
FDocumented harm, or risk without benefit