Chaudhry AS, Kochhar R, Kohli KK Genetic polymorphism of CYP2C19 & therapeutic response to proton pump inhibitors. Indian J Med Res. 2008 Jun;127(6):521-30. Review.
Furuta T, Graham DY Pharmacologic aspects of eradication therapy for Helicobacter pylori Infection. Gastroenterol Clin North Am. 2010 Sep;39(3):465-80. doi: 10.1016/j.gtc.2010.08.007. Review.
Furuta T, Sugimoto M, Shirai N, Ishizaki T CYP2C19 pharmacogenomics associated with therapy of Helicobacter pylori infection and gastro-esophageal reflux diseases with a proton pump inhibitor. Pharmacogenomics. 2007 Sep;8(9):1199-210. Review.
Graham DY, Shiotani A New concepts of resistance in the treatment of Helicobacter pylori infections. Nat Clin Pract Gastroenterol Hepatol. 2008 Jun;5(6):321-31. doi: 10.1038/ncpgasthep1138. Epub 2008 Apr 29. Review.
Sugimoto M, Furuta T Efficacy of tailored Helicobacter pylori eradication therapy based on antibiotic susceptibility and CYP2C19 genotype. World J Gastroenterol. 2014 Jun 7;20(21):6400-11. doi: 10.3748/wjg.v20.i21.6400. Review.
Tang HL, Li Y, Hu YF, Xie HG, Zhai SD Effects of CYP2C19 loss-of-function variants on the eradication of H. pylori infection in patients treated with proton pump inhibitor-based triple therapy regimens: a meta-analysis of randomized clinical trials. PLoS One. 2013 Apr 30;8(4):e62162. doi: 10.1371/journal.pone.0062162. Print 2013.
Effect of the CYP2C19 Polymorphism in Helicobacter Pylori Eradication
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.