[Risk factor for antibiotic-associated diarrhea. A review of the literature]

Antibiotic associated diarrhea (AAD) is a common adverse reaction to most types of antibiotics with frequencies ranging from 5-39%, depending upon the specific type of antibiotic and the presence of other risk factors. The pathogenesis of antibiotic associated diarrhea is mediated through the disruption of the normal flora and overgrowth of pathogens or through metabolic imbalances. Beside risk factors associated with the type and duration of antibiotic therapy, host factors include the extremes of age (< 6 years or > 65 years), severe underlying disease, presence of other chronic intestinal conditions, immunosuppression, prior history of AAD and exposures during recent hospitalizations (surgery, nasogastric tube feeding). Factors which have not been significantly associated with antibiotic associated diarrhea include gender, dose or route of the inciting antibiotic and inflammatory bowel disease. The clinical impact of AAD is reflected by potential severity of the illness (PMC), possible consequences of the disruption in the treatment of the primary infection, higher medical costs, increased hospital stays and increased rates of morbidity and mortality. The key to decreasing these consequences is prompt diagnosis followed by effective treatment and institution of control measures and preventive treatments in patients at risk.