[Pharmacokinetics of ampicillin in peritonitis in children].

Ampicillin levels in the blood serum and abdominal cavity biosubstrates of children with appendicular peritonitis were studied. The antibiotic was administered as intravenous jet infusion in single doses of 12--15 and 25--30 mg/kg and drop infusion continuously for 24 hour in doses of 150 and 250--300 mg/kg. Administration of the drug as intravenous jet infusion provided therapeutical ampicillin levels in the appendix tissue and abdominal cavity exudate. Administration of increased doses of the drug resulted in its higher biosubstrate levels. It was found that the level of the appendix destruction had a significant effect on the antibiotic level in this organ. In cases with gangrenous appendititis the ampicillin levels were 1.5--2.2 times lower than those in cases with catarrhal appendititis. The studies on the effect of the infusion therapy on ampicillin pharmacokinetics showed that the volume of the liquids administered intravenously had no significant influence on the antibiotic circulation in the blood. A continuous drop infusion provided high and stable ampicillin levels in the blood serum which significantly exceeded the antibiotic MIC. During the post-operative period the antibiotic levels in the blood serum after intraperitoneal administration were determined. The data showed that ampicillin administered intravenously 2--3 days after the operation was absorbed into the blood in insignificant amounts.