title: Rational prescription of drugs within similar therapeutic or structural class for gastrointestinal disease treatment: drug metabolism and its related interactions.
abstract: OBJECTIVE
  To review and summarize drug metabolism and its related interactions in prescribing drugs within the similar therapeutic or structural class for gastrointestinal disease treatment so as to promote rational use of medicines in clinical practice.
  
  
  METHODS
  Relevant literature was identified by performing MEDLINE/Pubmed searches covering the period from 1988 to 2006.
  
  
  RESULTS
  Seven classes of drugs were chosen, including gastric proton pump inhibitors, histamine H(2)-receptor antagonists, benzamide-type gastroprokinetic agents, selective 5-HT(3) receptor antagonists, fluoroquinolones, macrolide antibiotics and azole antifungals. They showed significant differences in metabolic profile (i.e., the fraction of drug metabolized by cytochrome P450 (CYP), CYP reaction phenotype, impact of CYP genotype on interindividual pharmacokinetics variability and CYP-mediated drug-drug interaction potential). Many events of severe adverse drug reactions and treatment failures were closely related to the ignorance of the above issues.
  
  
  CONCLUSIONS
  Clinicians should acquaint themselves with what kind of drug has less interpatient variability in clearance and whether to perform CYP genotyping prior to initiation of therapy. The relevant CYP knowledge helps clinicians to enhance the management of patients with gastrointestinal disease who may require treatment with polytherapeutic regimens.
authors.affiliation: Department of Clinical Pharmacology and Clinical Pharmacy, the 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, Zhejiang Province, China. zhouquan142602@zju.edu.cn
authors.forename: Quan
authors.initials: Q
authors.lastname: Zhou
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Yan
authors.forename: Zhong-Miao
authors.initials: ZM
authors.lastname: Zhang
authors.forename: Wen-Sheng
authors.initials: WS
authors.lastname: Pan
authors.forename: Su
authors.initials: S
authors.lastname: Zeng
mesh_terms: D001549:Benzamides / Q000627:therapeutic use; D003577:Cytochrome P-450 Enzyme System / Q000502:physiology; D004347:Drug Interactions; D011307:Drug Prescriptions; D024841:Fluoroquinolones / Q000627:therapeutic use; D005765:Gastrointestinal Agents / Q000378:metabolism / Q000627:therapeutic use*; D005767:Gastrointestinal Diseases / Q000188:drug therapy*; D006635:Histamine H2 Antagonists / Q000627:therapeutic use; D006801:Humans; D007654:Ketoconazole / Q000627:therapeutic use; D018942:Macrolides / Q000627:therapeutic use; D054328:Proton Pump Inhibitors / Q000627:therapeutic use; D012702:Serotonin Antagonists / Q000627:therapeutic use
chemical_list: D001549:Benzamides; D024841:Fluoroquinolones; D005765:Gastrointestinal Agents; D006635:Histamine H2 Antagonists; D018942:Macrolides; D054328:Proton Pump Inhibitors; D012702:Serotonin Antagonists; D003577:Cytochrome P-450 Enzyme System; D007654:Ketoconazole