1. Efficacy of a Nitazoxanide Based Regimen for Helicobacter pylori (HP) Eradication Campitelli E 1, Paszkiewich A 1, Ibarra D 1, Zanotti B 1, Peré F 1, Ronchetti R 1, Lago N 1, Corti R 2, Améndola R 2, Doweck J 2, Chaar E 3, Perissé E 3, Di Risio C 3, Barcia T 4, Pignataro S 4, Rubio H 4, Díaz M 5 BACKGROUND: Claritromycin and metronidazole are widely utilized as the basis of HP therapy. Unfortunately, increasing drug resistance to these drugs is one of the most prevalent reasons for HP treatment failures. Nitazoxanide is an anti-infective drug with demonstrated activity against protozoa and anaerobic bacteria including HP. Nitazoxanide exerts its clinical efficacy on HP by interfering with anaerobic energy metabolism at the PFOR enzyme. In vitro data indicates nitazoxanide and tizoxanide (an active metabolite) are highly active against HP including metronidazole resistant strains. Other studies have demonstrated that nitazoxanide does not possess mutagenic activity, cause DNA fragmentation, or promote cross-resistance with metronidazole. AIM: This study evaluates the efficacy and safety of nitazoxanide in conjunction with lansoprazole and amoxicillin in a 7-day regimen for the eradication of HP in previously untreated patients. METHODS:  An open label study to evaluate the safety and efficacy of a one- week triple drug regimen of nitazoxanide, lansoprazole and amoxicillin in adult patients with treatment naïve HP.  All patients had Active Superficial Gastritis (ASG) and active HP infection.  The diagnosis of HP was confirmed by both 14 C-Urea Breath Test ( 14 C-UBT) and endoscopic biopsy, overall 100 patients were enrolled in the study.  Patients received nitazoxanide 500 mg BID, lansoprazole 30 mg BID and amoxicillin 1000 mg BID for 7 days. Proton pump inhibitors were discontinued post treatment and therapeutic efficacy was assessed by 14 C-UBT performed between the 6 th and 8 th week after the completion of therapy.  Eradication was defined as a negative 14 C-UBT, and failure as a positive 14 C-UBT at the 6 to 8 week follow-up assessment.  Evaluations for safety and tolerability of the regimen were made via interview and physical examination. Table 1: Scheme of Treatment RESULTS: Figure 1: Patients flowchart Figure 2: Endoscopic biopsy Figure 3: Treatment outcome CONCLUSIONS  A 7-day regimen of nitazoxanide, lansooprazole, and amoxicillin twice daily is effective for the eradication of HP infection in treatment naïve patients  In addition, the regimen was well-tolerated and associated with good patient compliance  Due to increasing patterns observed with claritromycin and metronidazole, nitazoxanide may offer a valuable alternative to these medications as a foundation for HP therapy. REFERENCES 1. Hemphill A, Mueller J, Esposito thiazolide anti-infective agent for the treatment of gastrointestinal infections. Exp Opinion. Pharmacotherapy 2006 May; 7: 953-6 2. Megraud F., Occhialini A., Rossignol J.F. 1998. Nitazoxanide, a Potential Drug for Eradication of Helicobacter pylori with No Cross-Resistance to Metronidazole. 42: 2836-2840. 3. Sisson G, Goodwing A, Raudonikiene A, Birks N, Mukhopadhayay A.K, Berg D, & Hoffman, P. 2002. Identification of Enzymes Associated with Reductive Activation and Action of Nitazoxanide, Nitrofurans, and Metronidazole in Helicobacter pylori. 46: 2116-2123 4. Hoffman P., Sisson G., Croxen M., Welch K., Harman W., Cremades N., Morash M. 2007. Antiparasitic Drug Nitazoxanide Inhibits the Pyruvate Oxidoreductases of Helicobacter pylori, Selected Anaerobic Bacteria and Parasites, and Campylobacter jejuni. 51;3: 868-876 AKNOWLEDGEMENT: This study was supported by a grant from Roemmers-Argentina 1 Hospital Aeronáutico, Buenos Aires, Argentina; 2 Hospital Udaondo, Buenos Aires, Argentina; 3 Hospital Penna, Buenos Aires, Argentina; 4 CEED, Buenos Aires, Argentina; 5 Hospital Británico, Buenos Aires, Argentina Pathology Active Superficial Gastritis (ASG) HP infection. Diagnostic Method 14C- Urea Breath Test Endoscopic biopsy Treatment Nitazoxanide 500 mg BID x 7 days Lansoprazole 30 mg BID x 7 days Amoxicillin 1000 mg BID x 7 days 100 patients enrolled 9 patients withdrawn (6 were 14C-UBT negative) 91 evaluable Histology of endoscopic biopsy samples by three different methods. A. Warting Starring specific Stain for HP B. Giemsa stain to improve SP vision. C. Hematoxilin-eosin stain from antrum mucosae. Failure 14C- Urea Breath Test positive 9/91 9% Cure 14C- Urea Breath Test negative 82/91 90% Presented at American College of Gastroenterology Annual Scientific Meeting October 3-8, 2008; Orlando, Florida ABC