Absorption of intraperitoneally administered ampicillin (Pentrexyl [Belgium]; Penbritin, comparable US product) was studied in six patients with diffuse peritonitis, treated postoperatively with continuous peritoneal lavage. One liter of lavage solution containing 100mg/100 ml of ampicillin was exchanged each hour. Ten exchanges were performed daily for two days. During the whole exchange period high concentrations of ampicillin were present in the peritoneal cavity. Since the average absorption rate was as much as 74%, serum concentrations were well within the therapeutic range.
Normann E, Aune S. Absorption of Ampicillin From the Peritoneal CavityIn Patients With Diffuse Peritonitis. Arch Surg. 1971;102(5):469-470. doi:10.1001/archsurg.1971.01350050035011