Address of Corresponding Author

Chemotherapy 2005;51 (Suppl. 1):36-66 (DOI: 10.1159/000081990)

  Key Words

• Rifaximin
• Rifamycin
• Antibiotic
• Gut bacteria
• Enteric infection
• Diarrhea, infectious
• Hepatic encephalopathy
• Small intestine bacterial overgrowth
• Inflammatory bowel disease
• Colonic diverticular disease
• Irritable bowel syndrome
• Constipation
• Clostridium difficile infection
• Helicobacter pylori infection
• Colorectal surgery
• Bowel decontamination, selective
• Pancreatitis, acute
• Bacterial peritonitis, spontaneous
• Nonsteroidal anti-inflammatory drug enteropathy

  Abstract

Rifaximin (4-deoxy-4'-methylpyrido[1',2'-1,2]imidazo- [5,4-c]-rifamycin SV) is a synthetic antibiotic designed to modify the parent compound, rifamycin, in order to achieve low gastrointestinal (GI) absorption while retaining good antibacterial activity. Both experimental and clinical pharmacology clearly show that this compound is a nonsystemic antibiotic with a broad spectrum of antibacterial action covering Gram-positive and Gram-negative organisms, both aerobes and anaerobes. Being virtually nonabsorbed, its bioavailability within the GI tract is rather high with intraluminal and fecal drug concentrations that largely exceed the minimal inhibitory concentration values observed in vitro against a wide range of pathogenic organisms. The GI tract represents, therefore, the primary therapeutic target and GI infections the main indication. The appreciation of the pathogenic role of gut bacteria in several organic and functional GI diseases has increasingly broadened its clinical use, which is now extended to hepatic encephalopathy, small intestine bacterial overgrowth, inflammatory bowel disease and colonic diverticular disease. Potential indications include the irritable bowel syndrome and chronic constipation, Clostridium difficile infection and bowel preparation before colorectal surgery. Because of its antibacterial activity against the microorganism and the lack of strains with primary resistance, some preliminary studies have explored the rifaximin potential for Helicobacter pylori eradication. Oral administration of this drug, by getting rid of enteric bacteria, could also be employed to achieve selective bowel decontamination in acute pancreatitis, liver cirrhosis (thus preventing spontaneous bacterial peritonitis) and nonsteroidal anti-inflammatory drug (NSAID) use (lessening in that way NSAID enteropathy). This antibiotic has, therefore, little value outside the enteric area and this will minimize both antimicrobial resistance and systemic adverse events. Indeed, the drug proved to be safe in all patient populations, including young children. Although rifaximin has stood the test of time, it still attracts the attention of both basic scientists and clinicians. As a matter of fact, with the advancement of the knowledge on microbial-gut interactions in health and disease novel indications and new drug regimens are being explored. Besides widening the clinical use, the research on rifaximin is also focused on the synthesis of new derivatives and on the development of original formulations designed to expand the spectrum of its clinical use.

Copyright © 2005 S. Karger AG, Basel

  Author Contacts

Prof. Carmelo Scarpignato, MD, DSc, PharmD, FCP, FACG
Laboratory of Clinical Pharmacology, School of Medicine and Dentistry
University of Parma, Via Volturno, 39
IT-43100 Parma (Italy)
Tel. +39 0521 903863, eFax +1 603 8435621, E-Mail scarpi@tin.it

  Article Information

Number of Print Pages : 31
Number of Figures : 10, Number of Tables : 14, Number of References : 278