PHARMACOGENETICS Effects of CYP2C19, MDR1, and interleukin 1-B gene variants on the eradication rate of Helicobacter pylori infection by triple therapy with pantoprazole, amoxicillin, and metronidazole Barbara Gawrońska-Szklarz & Andrzej Siuda & Mateusz Kurzawski & Dariusz Bielicki & Wojciech Marlicz & Marek Droździk Received: 21 January 2010 / Accepted: 21 March 2010 / Published online: 8 April 2010 # Springer-Verlag 2010 Abstract Objective Eradication of H. pylori is an important treatment strategy in peptic ulcer patients. Current regimens of eradication consist of proton pump inhibitor (PPI) and two antibiotics. Effects of PPI may depend on their metabolism, and other factors important for the pathophys- iology of peptic ulcer disease. Aim of the present study was to evaluate an association of CYP2C19, MDR1, and IL-1B polymorphisms with the eradication rate of H. pylori in Polish Caucasian patients treated with a triple therapy of pantoprazole, amoxicillin, and metronidazole. Methods A total of 139 peptic ulcer patients, positive for H. pylori infection, were treated with triple therapy (pantopra- zole + amoxicillin + metronidazole). Subsequently, the patients were divided into two groups (group 1, success, and group 2, failure of eradication after therapy) and genotyped by the PCR-RFLP method for the presence of CYP2C19 variant alleles (*2, *3, and *17), and MDR1 3435C>T and IL-1B +3954C>T polymorphisms. Pantopra- zole serum concentrations were measured using the HPLC method. Results No significant differences in frequency or distribu- tion of CYP2C19 genotypes were found between the two groups of patients (i.e., with successful H. pylori eradica- tion and treatment failure). However, any carrier of defective CYP2C19*2/*2 genotype was found among patients with treatment failure. Similarly, MDR1 and IL- 1B genotypes were found to be significantly associated with the success or failure of H. pylori eradication. Univariate and multivariate analysis of the genotypes did not reveal any significant association between the genotypes and H. pylori eradication. Pantoprazole concentrations differed significantly, and were the highest in patients with defective allele CYP2C19*2 carriers and lowest in hyperactive genotype homozygotes CYP2C19*17/*17. Conclusion The results suggest that the CYP2C19 genotype contrary to MDR1 and IL-1B genotypes may have an impact on the efficacy of H. pylori eradication in peptic ulcer patients treated with pantoprazole in Polish Caucasian peptic ulcer patients administered pantoprazole, amoxicil- lin, and metronidazole. Keywords CYP2C19 . MDR1 . Interleukin-1β . Genetic polymorphism . Peptic ulcer . H. pylori . Pharmacogenetics Introduction Eradication of H. pylori is an important treatment strategy in a variety of upper gastrointestinal disorders, such as peptic ulcer, chronic gastritis, and mucosa-associated B. Gawrońska-Szklarz : M. Kurzawski : M. Droździk (*) Department of Pharmacology, Pomeranian Medical University, Powstancow Wlkp. 72, 70-111 Szczecin, Poland e-mail: drozdzik@sci.pam.szczecin.pl A. Siuda Clinical Department of Internal Diseases, Regional Hospital, Piłsudskiego 8, 66-530 Drezdenko, Poland D. Bielicki : W. Marlicz Department of Gastroenterology, Pomeranian Medical University, Powstancow Wlkp. 72, 70-111 Szczecin, Poland Eur J Clin Pharmacol (2010) 66:681–687 DOI 10.1007/s00228-010-0818-1