Summary: A group of ANTI-BACTERIAL AGENTS characterized by a chromophoric naphthohydroquinone group spanned by an aliphatic bridge not previously found in other known ANTI-BACTERIAL AGENTS. They have been isolated from fermentation broths of Streptomyces mediterranei.

Top Publications

  1. Adachi J, DuPont H. Rifaximin: a novel nonabsorbed rifamycin for gastrointestinal disorders. Clin Infect Dis. 2006;42:541-7 pubmed
    ..Additional studies should be performed to further define the role of rifaximin in the treatment of gastrointestinal diseases in adults and children. ..
  2. Feklistov A, Mekler V, Jiang Q, Westblade L, Irschik H, Jansen R, et al. Rifamycins do not function by allosteric modulation of binding of Mg2+ to the RNA polymerase active center. Proc Natl Acad Sci U S A. 2008;105:14820-5 pubmed publisher
    ..Recently, Artsimovitch et al. [(2005) Cell 122:351-363] proposed that rifamycins function by allosteric modulation of binding of Mg(2+) to the RNAP active center and presented three lines of ..
  3. Gasbarrini A, Lauritano E, Nista E, Candelli M, Gabrielli M, Santoro M, et al. Rifaximin-based regimens for eradication of Helicobacter pylori: a pilot study. Dig Dis. 2006;24:195-200 pubmed
    ..Rifaximin-based therapy showed optimal compliance but a limited eradication rate compared to standard first-line treatment. Further investigations are needed to evaluate different dosages and combinations. ..
  4. Gerard L, Garey K, DuPont H. Rifaximin: a nonabsorbable rifamycin antibiotic for use in nonsystemic gastrointestinal infections. Expert Rev Anti Infect Ther. 2005;3:201-11 pubmed
    ..Importantly, rifaximin does not appear to lead to bacterial resistance. Rifaximin has an excellent safety profile and adverse drug reactions have been comparable to those associated with the placebo control agent. ..
  5. Cheng J, Shah Y, Ma X, Pang X, Tanaka T, Kodama T, et al. Therapeutic role of rifaximin in inflammatory bowel disease: clinical implication of human pregnane X receptor activation. J Pharmacol Exp Ther. 2010;335:32-41 pubmed publisher
  6. Isaacs K, Sandler R, Abreu M, Picco M, Hanauer S, Bickston S, et al. Rifaximin for the treatment of active pouchitis: a randomized, double-blind, placebo-controlled pilot study. Inflamm Bowel Dis. 2007;13:1250-5 pubmed
    ..A larger trial would be required to determine if rifaximin is effective for the treatment of active pouchitis. Rifaximin was well tolerated. ..
  7. Leevy C, Phillips J. Hospitalizations during the use of rifaximin versus lactulose for the treatment of hepatic encephalopathy. Dig Dis Sci. 2007;52:737-41 pubmed
    ..001). Treatment of hepatic encephalopathy with rifaximin was associated with lower hospitalization frequency and duration, lower hospital charges, better clinical status, and fewer adverse events. ..
  8. Scarpignato C, Pelosini I. Experimental and clinical pharmacology of rifaximin, a gastrointestinal selective antibiotic. Digestion. 2006;73 Suppl 1:13-27 pubmed
  9. Jiang Z, DuPont H. Rifaximin: in vitro and in vivo antibacterial activity--a review. Chemotherapy. 2005;51 Suppl 1:67-72 pubmed
    ..The available data suggest that rifaximin is active in vitro and in vivo in the treatment of bacterial infection of adults and children...

More Information


  1. Molodtsov V, Nawarathne I, Scharf N, Kirchhoff P, Showalter H, Garcia G, et al. X-ray crystal structures of the Escherichia coli RNA polymerase in complex with benzoxazinorifamycins. J Med Chem. 2013;56:4758-63 pubmed publisher
    ..Among many semisynthetic rifamycins, benzoxazinorifamycins have great potential for TB treatment due to their superior affinity for wild-type and ..
  2. DuPont H, Jiang Z, Okhuysen P, Ericsson C, de la Cabada F, Ke S, et al. A randomized, double-blind, placebo-controlled trial of rifaximin to prevent travelers' diarrhea. Ann Intern Med. 2005;142:805-12 pubmed
    ..Future studies should evaluate whether rifaximin is effective in preventing postinfectious irritable bowel syndrome. ..
  3. Abdelrazeq A, Kelly S, Lund J, Leveson S. Rifaximin-ciprofloxacin combination therapy is effective in chronic active refractory pouchitis. Colorectal Dis. 2005;7:182-6 pubmed
    ..Rifaximin-ciprofloxacin combination therapy is safe and objectively effective in chronic active refractory pouchitis and may salvage a significant percentage of 'at risk pouches'. ..
  4. Flores J, DuPont H, Jiang Z, Okhuysen P, Melendez Romero J, Gonzalez Estrada A, et al. A randomized, double-blind, pilot study of rifaximin 550 mg versus placebo in the prevention of travelers' diarrhea in Mexico during the dry season. J Travel Med. 2011;18:333-6 pubmed publisher
    ..03). No clinically significant or serious adverse events were reported. Antibiotic prophylaxis of TD in Mexico during the dry season needs to be further studied and its benefits weighed against the benefits of self-treatment. ..
  5. Bajaj J, Ridlon J, Hylemon P, Thacker L, Heuman D, Smith S, et al. Linkage of gut microbiome with cognition in hepatic encephalopathy. Am J Physiol Gastrointest Liver Physiol. 2012;302:G168-75 pubmed publisher
    ..Specific bacterial families (Alcaligeneceae, Porphyromonadaceae, Enterobacteriaceae) are strongly associated with cognition and inflammation in HE. ..
  6. Martinez Sandoval F, Ericsson C, Jiang Z, Okhuysen P, Romero J, Hernandez N, et al. Prevention of travelers' diarrhea with rifaximin in US travelers to Mexico. J Travel Med. 2010;17:111-7 pubmed publisher
    ..Rifaximin chemoprevention should be considered for TD in appropriate individuals traveling to high-risk regions. ..
  7. Gorbach S. How to hit the runs for fifty million travelers at risk. Ann Intern Med. 2005;142:861-2 pubmed
  8. Koo H, DuPont H. Rifaximin: a unique gastrointestinal-selective antibiotic for enteric diseases. Curr Opin Gastroenterol. 2010;26:17-25 pubmed publisher
    ..Future studies will determine whether the development of significant bacterial resistance will limit rifaximin use. ..
  9. Sidhu S, Goyal O, Mishra B, Sood A, Chhina R, Soni R. Rifaximin improves psychometric performance and health-related quality of life in patients with minimal hepatic encephalopathy (the RIME Trial). Am J Gastroenterol. 2011;106:307-16 pubmed publisher
    ..66-11.06); 8 weeks, 8.51 (95% CI, 7.35-9.67); P=0.82). Improvement in HRQOL correlated with improvement in NP tests. Rifaximin was well tolerated. Rifaximin significantly improves both cognitive functions and HRQOL in patients with MHE. ..
  10. Lauritano E, Gabrielli M, Scarpellini E, Ojetti V, Roccarina D, Villita A, et al. Antibiotic therapy in small intestinal bacterial overgrowth: rifaximin versus metronidazole. Eur Rev Med Pharmacol Sci. 2009;13:111-6 pubmed
    ..Either the present study or recent evidencies suggest that rifaximin represents a good choice for the management of patients affected by SIBO. ..
  11. Brown E, Xue Q, Jiang Z, Xu Y, DuPont H. Pretreatment of epithelial cells with rifaximin alters bacterial attachment and internalization profiles. Antimicrob Agents Chemother. 2010;54:388-96 pubmed publisher
    ..The study provides evidence that rifaximin-mediated changes in epithelial cell physiology are associated with changes in bacterial attachment/internalization and reduced inflammatory cytokine release. ..
  12. Taylor D, McKenzie R, Durbin A, Carpenter C, Atzinger C, Haake R, et al. Rifaximin, a nonabsorbed oral antibiotic, prevents shigellosis after experimental challenge. Clin Infect Dis. 2006;42:1283-8 pubmed
    ..001). Rifaximin was effective and well tolerated, compared with placebo, in preventing shigellosis in this double-blind study of volunteers challenged with S. flexneri 2a. ..
  13. Prantera C, Lochs H, Grimaldi M, Danese S, Scribano M, Gionchetti P. Rifaximin-extended intestinal release induces remission in patients with moderately active Crohn's disease. Gastroenterology. 2012;142:473-481.e4 pubmed publisher
    ..Administration of 800 mg rifaximin-EIR twice daily for 12 weeks induced remission with few adverse events in patients with moderately active CD. ..
  14. Jiang Z, Ke S, DuPont H. Rifaximin-induced alteration of virulence of diarrhoea-producing Escherichia coli and Shigella sonnei. Int J Antimicrob Agents. 2010;35:278-81 pubmed publisher
    ..At subinhibitory concentrations, rifaximin alters the virulence of ETEC, EAEC and S. sonnei isolates. These findings help explain the efficacy of rifaximin despite minimal alteration of colonic flora. ..
  15. Quesada M, Sanfeliu I, Junquera F, Segura F, Calvet X. [Evaluation of Helicobacter pylori susceptibility to rifaximin]. Gastroenterol Hepatol. 2004;27:393-6 pubmed
    ..pylori infection. Because rifaximin is active against H. pylori strains resistant to clarithromycin, it could be useful in combination with this drug or in the treatment of therapeutic failure. ..
  16. DuPont H. Travellers' diarrhoea: contemporary approaches to therapy and prevention. Drugs. 2006;66:303-14 pubmed
    ..Vaccines and immunoprophylactic products may be beneficial for prevention of a subset of individuals otherwise developing diarrhoea. ..
  17. Artsimovitch I, Vassylyeva M, Svetlov D, Svetlov V, Perederina A, Igarashi N, et al. Allosteric modulation of the RNA polymerase catalytic reaction is an essential component of transcription control by rifamycins. Cell. 2005;122:351-63 pubmed publisher
    b>Rifamycins, the clinically important antibiotics, target bacterial RNA polymerase (RNAP)...
  18. Infante R, Ericsson C, Jiang Z, Ke S, Steffen R, Riopel L, et al. Enteroaggregative Escherichia coli diarrhea in travelers: response to rifaximin therapy. Clin Gastroenterol Hepatol. 2004;2:135-8 pubmed
    ..The study provides information on the value of the poorly absorbed drug rifaximin in therapy of travelers' diarrhea. ..
  19. Koo H, DuPont H. Current and future developments in travelers' diarrhea therapy. Expert Rev Anti Infect Ther. 2006;4:417-27 pubmed
  20. Jiang Z, DuPont H, La Rocco M, Garey K. In vitro susceptibility of Clostridium difficile to rifaximin and rifampin in 359 consecutive isolates at a university hospital in Houston, Texas. J Clin Pathol. 2010;63:355-8 pubmed publisher
    ..The study demonstrates that rifaximin has high-level activity against C difficile in vitro. Determination of resistance to rifampin by E strip did not predict rifaximin resistance. ..
  21. Wilson M, Gulder T, Mahmud T, Moore B. Shared biosynthesis of the saliniketals and rifamycins in Salinispora arenicola is controlled by the sare1259-encoded cytochrome P450. J Am Chem Soc. 2010;132:12757-65 pubmed publisher
    ..Our results suggest that a single enzyme, the cytochrome P450 monooxygenase encoded by sare1259, catalyzes multiple oxidative rearrangement reactions on 34a-deoxyrifamyin W to yield both the saliniketal and rifamycin structural classes. ..
  22. Huang D, DuPont H. Rifaximin--a novel antimicrobial for enteric infections. J Infect. 2005;50:97-106 pubmed
  23. Johnson S, Schriever C, Galang M, Kelly C, Gerding D. Interruption of recurrent Clostridium difficile-associated diarrhea episodes by serial therapy with vancomycin and rifaximin. Clin Infect Dis. 2007;44:846-8 pubmed
    ..difficile was recovered after treatment. A controlled trial for treating recurrent Clostridium difficile-associated diarrhea appears to be warranted. ..
  24. DuPont H. Biologic properties and clinical uses of rifaximin. Expert Opin Pharmacother. 2011;12:293-302 pubmed publisher
    ..The different mechanisms of action of rifaximin potentially explain the use of the drug in widely varied diseases and syndromes. ..
  25. Maccaferri S, Vitali B, Klinder A, Kolida S, Ndagijimana M, Laghi L, et al. Rifaximin modulates the colonic microbiota of patients with Crohn's disease: an in vitro approach using a continuous culture colonic model system. J Antimicrob Chemother. 2010;65:2556-65 pubmed publisher
    ..We demonstrated that rifaximin, while not altering the overall structure of the human colonic microbiota, increased bifidobacteria and led to variation of metabolic profiles associated with potential beneficial effects on the host. ..
  26. Fumi A, Trexler K. Rifaximin treatment for symptoms of irritable bowel syndrome. Ann Pharmacother. 2008;42:408-12 pubmed publisher
    ..Rifaximin offers a potential new therapeutic option for patients with refractory IBS. Larger, well-designed trials are necessary to elucidate the role of rifaximin in the treatment of this disorder. ..
  27. DuPont H, Haake R, Taylor D, Ericsson C, Jiang Z, Okhuysen P, et al. Rifaximin treatment of pathogen-negative travelers' diarrhea. J Travel Med. 2007;14:16-9 pubmed
    ..These results are consistent with the hypothesis that undetected bacterial pathogens are the most likely cause of travelers' diarrhea without definable cause. ..
  28. Bass N, Mullen K, Sanyal A, Poordad F, Neff G, Leevy C, et al. Rifaximin treatment in hepatic encephalopathy. N Engl J Med. 2010;362:1071-81 pubmed publisher
    ..Rifaximin treatment also significantly reduced the risk of hospitalization involving hepatic encephalopathy. (ClinicalTrials.gov number, NCT00298038.) ..
  29. Khan K, Ullman T, Ford A, Abreu M, Abadir A, Abadir A, et al. Antibiotic therapy in inflammatory bowel disease: a systematic review and meta-analysis. Am J Gastroenterol. 2011;106:661-73 pubmed publisher
    ..This systematic review is a mandate for further trials of antibiotic therapy in IBD. ..
  30. O Connor J, Galang M, Sambol S, Hecht D, Vedantam G, Gerding D, et al. Rifampin and rifaximin resistance in clinical isolates of Clostridium difficile. Antimicrob Agents Chemother. 2008;52:2813-7 pubmed publisher
    ..was investigated by sequence analysis of rpoB, which encodes the beta subunit of RNA polymerase, the target of rifamycins. Resistance-associated rpoB sequence differences that resulted in specific amino acid substitutions in an ..
  31. DuPont H, Jiang Z. Influence of rifaximin treatment on the susceptibility of intestinal Gram-negative flora and enterococci. Clin Microbiol Infect. 2004;10:1009-11 pubmed
    ..Enterococci recovered pre- and post-treatment showed similar susceptibilities. Rifaximin did not select for significant resistance in the Gram-negative and Gram-positive intestinal flora during therapy. ..
  32. Gionchetti P, Rizzello F, Venturi A, Ugolini F, Rossi M, Brigidi P, et al. Antibiotic combination therapy in patients with chronic, treatment-resistant pouchitis. Aliment Pharmacol Ther. 1999;13:713-8 pubmed
  33. Mas A, Rodes J, Sunyer L, Rodrigo L, Planas R, Vargas V, et al. Comparison of rifaximin and lactitol in the treatment of acute hepatic encephalopathy: results of a randomized, double-blind, double-dummy, controlled clinical trial. J Hepatol. 2003;38:51-8 pubmed
    ..No serious adverse events related to either treatment were found during the study. Rifaximin may be considered a useful and safe alternative therapy to lactitol in the treatment of acute hepatic encephalopathy in cirrhosis. ..
  34. Jiang Z, Ke S, Palazzini E, Riopel L, Dupont H. In vitro activity and fecal concentration of rifaximin after oral administration. Antimicrob Agents Chemother. 2000;44:2205-6 pubmed
    ..Rifaximin concentrations in stool the day after oral administration (800 mg daily for 3 days) were high (average, 7,961 microg/g), proving the value of the drug. ..
  35. Steffen R, Sack D, Riopel L, Jiang Z, Stürchler M, Ericsson C, et al. Therapy of travelers' diarrhea with rifaximin on various continents. Am J Gastroenterol. 2003;98:1073-8 pubmed
    ..Also, secondary clinical outcome measures were favorably influenced by the active agent. No relevant side effects were reported. Rifaximin is efficacious and safe for treatment of travelers' diarrhea at daily doses of 600 mg or higher. ..
  36. Williams R, James O, Warnes T, Morgan M. Evaluation of the efficacy and safety of rifaximin in the treatment of hepatic encephalopathy: a double-blind, randomized, dose-finding multi-centre study. Eur J Gastroenterol Hepatol. 2000;12:203-8 pubmed
    ..Rifaximin may be useful as alternative or adjuvant therapy for grade I-III hepatic encephalopathy in patients with cirrhosis at a dose of 1200 mg/day. ..
  37. Hartung I, Rude M, Schnarr N, Hunziker D, Khosla C. Stereochemical assignment of intermediates in the rifamycin biosynthetic pathway by precursor-directed biosynthesis. J Am Chem Soc. 2005;127:11202-3 pubmed
    Natural and semisynthetic rifamycins are clinically important inhibitors of bacterial DNA-dependent RNA polymerase...
  38. Zanger P, Nurjadi D, Gabor J, Gaile M, Kremsner P. Effectiveness of rifaximin in prevention of diarrhoea in individuals travelling to south and southeast Asia: a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet Infect Dis. 2013;13:946-54 pubmed publisher
    ..Similar studies are needed to inform travellers and practitioners about the effectiveness of this drug at other popular destinations. ..
  39. Fornai M, Antonioli L, Pellegrini C, Colucci R, Sacco D, Tirotta E, et al. Small bowel protection against NSAID-injury in rats: Effect of rifaximin, a poorly absorbed, GI targeted, antibiotic. Pharmacol Res. 2016;104:186-96 pubmed publisher
  40. Alonso Lomillo M, Domínguez Renedo O, Arcos Martínez M. Resolution of binary mixtures of rifamycin SV and rifampicin by UV/VIS spectroscopy and partial least-squares method (PLS). Chem Biodivers. 2004;1:1336-43 pubmed
    ..Finally, the methods were applied to the determination of these drugs in biological samples. ..
  41. Sharara A, Aoun E, Abdul Baki H, Mounzer R, Sidani S, Elhajj I. A randomized double-blind placebo-controlled trial of rifaximin in patients with abdominal bloating and flatulence. Am J Gastroenterol. 2006;101:326-33 pubmed
    ..To study the efficacy of rifaximin, a nonabsorbable antibiotic, in relieving chronic functional symptoms of bloating and flatulence...
  42. Di Stefano A, Rusca A, Loprete L, Dröge M, Moro L, Assandri A. Systemic absorption of rifamycin SV MMX administered as modified-release tablets in healthy volunteers. Antimicrob Agents Chemother. 2011;55:2122-8 pubmed publisher
    ..0410±0.0617. The total elimination of the unchanged rifamycin SV with feces was 87% of the administered oral dose. No significant effect of rifamycin SV on vital signs, electrocardiograms, or laboratory parameters was observed. ..
  43. Ono K, Hasegawa K, Naiki H, Yamada M. Anti-amyloidogenic activity of tannic acid and its activity to destabilize Alzheimer's beta-amyloid fibrils in vitro. Biochim Biophys Acta. 2004;1690:193-202 pubmed
    ..1 microM. Although the mechanism by which TA inhibits fAbeta formation from Abeta as well as destabilizes preformed fAbeta in vitro is still unclear, it could be a key molecule for the development of therapeutics for AD. ..
  44. Leise M, Poterucha J, Kamath P, Kim W. Management of hepatic encephalopathy in the hospital. Mayo Clin Proc. 2014;89:241-53 pubmed publisher
    ..Last, patients and their families should be counseled about the risk of motor vehicle accidents, which require mandatory reporting to the Department of Motor Vehicles in some states. ..
  45. Tursi A. Mesalazine for diverticular disease of the colon--a new role for an old drug. Expert Opin Pharmacother. 2005;6:69-74 pubmed
    ..More-over, in light of some preliminary results, it is probable that the association of mesalazine with probiotics may in the future be the first-choice treatment for mild-to-moderate uncomplicated attacks of acute diverticulitis. ..
  46. Turks M, Huang X, Vogel P. Expeditious asymmetric synthesis of a stereoheptad corresponding to the C(19)-C(27)-ansa chain of rifamycins: formal total synthesis of Rifamycin S. Chemistry. 2005;11:465-76 pubmed
    ..reaction with (2S)-2-methyl-3-[(tert-butyldimethylsilyl)oxy]propanal giving an aldol that is reduced into a stereoheptad corresponding to the C(19)-C(27)-segment of Rifamycins with high diastereoselectivity and enantiomeric excess.
  47. Neff G, Jones M, Jonas M, Ravinuthala R, Novick D, Kaiser T, et al. Lack of Clostridium difficile infection in patients treated with rifaximin for hepatic encephalopathy: a retrospective analysis. J Clin Gastroenterol. 2013;47:188-92 pubmed publisher
    ..None of these patients tested positive for C. difficile. This study demonstrates that treatment of HE with the safe, nonsystemic, gut-selective antibiotic rifaximin was not associated with the development of C. difficile infection. ..
  48. Kale Pradhan P, Zhao J, Palmer J, Wilhelm S. The role of antimicrobials in Crohn's disease. Expert Rev Gastroenterol Hepatol. 2013;7:281-8 pubmed publisher
    ..Antimicrobials, especially metronidazole, are promising for inducing remission in patients with colonic CD and preventing recurrence in postileocolonic resection. ..
  49. Pupov D, Kuzin I, Bass I, Kulbachinskiy A. Distinct functions of the RNA polymerase ? subunit region 3.2 in RNA priming and promoter escape. Nucleic Acids Res. 2014;42:4494-504 pubmed publisher
    ..2 contributes to allosteric inhibition of the initiating NTP binding by rifamycins. Thus, region ?3.2 performs distinct functions in transcription initiation and its inhibition by antibiotics...
  50. Bond T, Sorenson A, Schaeffer P. Functional characterisation of Burkholderia pseudomallei biotin protein ligase: A toolkit for anti-melioidosis drug development. Microbiol Res. 2017;199:40-48 pubmed publisher
    ..sepsis-related mortalities in northeast Thailand, and is intrinsically resistant to aminoglycosides, macrolides, rifamycins, cephalosporins, and nonureidopenicillins. There is no vaccine and its diagnosis is problematic...
  51. Kang Q, Shen Y, Bai L. Biosynthesis of 3,5-AHBA-derived natural products. Nat Prod Rep. 2012;29:243-63 pubmed publisher
    ..This review covers the biosynthesis of AHBA-derived natural products from a molecular genetics, chemical, and biochemical perspectives, and 174 references are cited. ..
  52. D Inca R, Pomerri F, Vettorato M, Dal Pont E, Di Leo V, Ferronato A, et al. Interaction between rifaximin and dietary fibre in patients with diverticular disease. Aliment Pharmacol Ther. 2007;25:771-9 pubmed
    ..0 h in placebo and from 54.4 +/- 31.9 to 45.1 +/- 32.4 h (P < 0.05) in rifaximin-treated patients. The administration of rifamixin improves the benefits of dietary fibre in uncomplicated DD by preventing its bacterial degradation. ..
  53. Pelosini I, Scarpignato C. Rifaximin, a peculiar rifamycin derivative: established and potential clinical use outside the gastrointestinal tract. Chemotherapy. 2005;51 Suppl 1:122-30 pubmed
    ..e. chlortetracycline or oxytetracycline), the usefulness of rifaximin in BV and periodontal disease needs to be further studied in well-designed clinical trials. ..