title: Entecavir: a step forward in combating hepatitis B disease.
abstract: BACKGROUND
  Entecavir (ETV) is a potent deoxyguanosine nucleoside analog with a very good safety record.
  
  
  OBJECTIVE
  This review provides a comprehensive overview on the mechanism of action, pharmacodynamics, pharmacokinetics, clinical efficacy and safety of entecavir obtained through an extensive literature search.
  
  
  CONCLUSIONS
  ETV inhibits all three steps of hepatitis B virus replication via entecavir--triphosphate, its intracellular active form, by dose-dependently competing with deoxyguanosine triphosphate for incorporation into DNA. Superior efficacy of ETV over lamivudine (LVD) has been shown in four double-blind, randomized controlled clinical trials encompassing a large cohort of treatment naive HBeAg-positive and HBeAg-negative patients and LVD-refractory HBeAg-positive patients. Prolongation of ETV treatment is associated with further improvement of efficacy. In treatment-naive patients, cumulative probability of ETV resistance and viral breakthrough after 5 years of treatment has been reported as 1.2 and 0.8%, respectively. ETV displays low cytotoxicity in proliferating cultured liver cell and has an excellent safety in clinical use.
authors.affiliation: University of Ankara Medical School, Cebeci Tip Fakultesi Hastanesi, Gastroenteroloji Klinigi, Dikimevi, 06100 Ankara, Turkey. cihan.yurdaydin@medicine.ankara.edu.tr
authors.forename: Cihan
authors.initials: C
authors.lastname: Yurdaydin
mesh_terms: D000818:Animals; D002986:Clinical Trials as Topic; D024882:Drug Resistance, Viral / Q000187:drug effects; D006147:Guanine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology / Q000627:therapeutic use; D006509:Hepatitis B / Q000188:drug therapy*; D006801:Humans
chemical_list: C413685:entecavir; D006147:Guanine