Entecavir for the treatment of chronic hepatitis B.
Chronic infection with the hepatitis B virus remains a serious and life-threatening disease for approximately 5% of the world's population, despite the availability of effective vaccines. Although prognoses can be improved by chemotherapy, treatment options are limited and none has been consistently successful. Interferon-alpha, the longest established therapy, has limited efficacy, is slow-acting and frequently causes adverse effects. Newer drugs comprise of mainly nucleoside and nucleotide analogs. The two that are currently approved, lamivudine and adefovir dipivoxil, are well tolerated; both produce rapid and dramatic responses, but their effects may not be sustainable in the long-term due to the emergence of resistant virus. Development of resistance to lamivudine is approximately ten-times more frequent than development of resistance to adefovir dipivoxil (approximately 60 and 6%, respectively) during the first 3 years of therapy. Entecavir, a carbocyclic deoxyguanosine analog that is active against both lamivudine- and adefovir dipivoxil-resistant HBV, is in the vanguard of new antihepatitis B virus drugs that have progressed to Phase III clinical trials. It is the most potent antihepatitis B virus agent discovered to date.
Shaw
Tim
T
Victorian Infectious Diseases Reference Laboratory, 10 Wreckyn Street, North Melbourne, Victoria, 3051 Australia. tim.shaw@mh.org.au
Locarnini
Stephen
S
D000818:Animals; D000998:Antiviral Agents / Q000493:pharmacokinetics / Q000627:therapeutic use*; D024882:Drug Resistance, Viral; D006147:Guanine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000627:therapeutic use*; D006515:Hepatitis B virus / Q000187:drug effects; D019694:Hepatitis B, Chronic / Q000188:drug therapy*; D006801:Humans; D016032:Randomized Controlled Trials as Topic
D000998:Antiviral Agents; C413685:entecavir; D006147:Guanine