Treatment of intra-abdominal infections.

Intra-abdominal infections are caused by a mixture of aerobic, anaerobic and facultatively anaerobic bacteria. Experimental studies in animals and clinical trials indicate that antimicrobial therapy should provide adequate coverage for the whole range of isolates. Penicillins and cephalosporins with relatively limited activity against anaerobes have been associated with clinical failures in treating various types of mixed infections. Aminoglycosides are often used in combination with other drugs in the treatment of intra-abdominal infections. Recent studies have cast doubt on this practice because of increased resistance of Gram-negative bacilli to aminoglycosides and high rates of renal toxicity. Regimens that do not include an aminoglycoside have given good results in treatment of appendicitis, penetrating abdominal trauma, and peritonitis. Enterococci are frequently isolated from intra-abdominal infections, but evidence suggests that it is not necessary to direct treatment at this organism initially.