Cihan Yurdaydin1. 1. University of Ankara Medical School, Cebeci Tip Fakultesi Hastanesi, Gastroenteroloji Klinigi, Dikimevi, 06100 Ankara, Turkey. cihan.yurdaydin@medicine.ankara.edu.tr
Abstract
BACKGROUND: Entecavir (ETV) is a potent deoxyguanosine nucleoside analog with a very good safety record. OBJECTIVES/ METHODS: 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. RESULTS/ CONCLUSION: 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.
BACKGROUND:Entecavir (ETV) is a potent deoxyguanosine nucleoside analog with a very good safety record. OBJECTIVES/ METHODS: 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. RESULTS/ CONCLUSION: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.