New trends in non-absorbable antibiotics in gastrointestinal disease.

Numerous antibiotics have been used for several years in the treatment of intestinal diseases, the majority belonging to the class of aminoglycosides. These are effective against gram-positive and some gram-negative bacteria, above all aerobes, and do not therefore cover the entire range of microorganisms responsible for intestinal infections. With these antibiotics, moreover, it is not possible to exclude intestinal absorption which can lead to serious side effects. Other intestinal antibiotics, however, such as Vancomycin, have a restricted spectrum of action which limits their use. This study analyzes the pharmacological characteristics of a new non-absorbable antibiotics with particularly interesting properties from a clinical pharmacokinetic and pharmacodynamic point of view: Rifaximin. This drug has an extremely broad spectrum of action covering all intestinal germs, and its absorption is practically zero. The results of some controlled clinical studies in gastrointestinal diseases are examined, such as the treatment of infectious diarrhoea, of acute or chronic portal-caval encephalopathy and of diverticular disease of the colon. The possible role of Rifaximin in some intestinal diseases, such as small bowel bacterial overgrowth and Crohn's disease and ulcerative colitis, is also analyzed.