[Antibiotic-associated diarrhea]

The incidence of antibiotic-associated diarrhea (AAD) differs with the antibiotic and varies from 15 - 25 %. Most cases of AAD are directly or indirectly caused by alterations of gut microflora by the antibiotics resulting in clinically mild AAD cases due to functional disturbances of intestinal carbohydrate or bile acid metabolism. Alternatively, changes in the gut flora allow pathogens to proliferate. Clostridium difficile is responsible for 10 - 15 % of all cases of AAD and almost of all cases of antibiotic-associated pseudomembraneous colitis. There is also a growing body of evidence which supports the responsibility of Klebsiella oxytoca for the development of antibiotic-associated hemorrhagic colitis. Diagnosing Clostridium difficile-associated diarrhea should be based both on fecal-cytotoxin detection and culture. With respect to specific therapy, metronidazol has become the first choice whereas treatment with oral vancomycin should be reserved for patients who have contraindications or intolerance to or who have failed to respond to metronidazole. Probiotics such as Sacharomyces boulardii can reduce the risk of development. Restrictive antibiotic policies (e. g. restricting clindamycin and cephalosporins) and the implementation of a comprehensive hospital infection control have also been shown to be effective in reducing the incidence of AAD.