Penetration of sulbactam and ampicillin into peritoneal fluid.

Twenty-five patients undergoing elective intraabdominal surgery received either 1 or 2 g of ampicillin together with 1 g of sulbactam intravenously before surgery. The peritoneal levels of the agent were measured. Both compounds penetrated peritoneal fluid readily; the mean percentage of penetration by ampicillin was 92%; that of sulbactam was 96%. After 1 g of each agent, the peritoneal levels of sulbactam were 47% greater than those of ampicillin. Our results suggest that 2 g of ampicillin plus 1 g of sulbactam should provide peritoneal levels that would inhibit most susceptible beta-lactamase-producing pathogens encountered in intraabdominal sepsis.