Efficacy and safety of adefovir dipivoxil 20 mg daily in HBeAg-positive patients with lamivudine-resistant hepatitis B virus and a suboptimal virological response to adefovir dipivoxil 10 mg daily.
OBJECTIVE
Some patients receiving adefovir at the approved dose of 10 mg daily for chronic hepatitis B have a "suboptimal" virological response characterized by a slow and moderate decrease in viral replication.


METHODS
We assessed the efficacy and safety of adefovir 20 mg daily in patients with hepatitis B e antigen-positive chronic hepatitis B resistant to lamivudine and a suboptimal virological response to adefovir 10 mg daily add-on.


RESULTS
No amino acid substitutions known to confer adefovir resistance were found in these patients. In the five treated patients, the switch from 10 mg to 20 mg of adefovir daily significantly improved antiviral efficacy (-1.78+/-0.28 log international units/mL versus -3.73+/-0.51 log international units/mL, respectively, p=0.0039), and alanine aminotransferase levels normalized in all but one of the patients. No signs of renal dysfunction occurred.


CONCLUSIONS
These results suggest: (i) that suboptimal responses to adefovir 10 mg daily are due to underdosing; and (ii) that increasing the adefovir dose to 20 mg daily is beneficial and safe in patients with lamivudine-resistant HBV and a suboptimal response to adefovir 10 mg daily, especially when alanine aminotransferase levels are elevated and/or the liver disease is severe or rapidly progressive. Careful monitoring of renal function is necessary.
Hézode
Christophe
C
Department of Hepatology and Gastroenterology, Hôpital Henri Mondor, Assistance Publique-Hôpitaux de Paris, Université Paris XII, Créteil, France.
Chevaliez
Stéphane
S
Bouvier-Alias
Magali
M
Roudot-Thoraval
Françoise
F
Brillet
Rozenn
R
Zafrani
Elie-Serge
ES
Dhumeaux
Daniel
D
Pawlotsky
Jean-Michel
JM
D000225:Adenine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000410:Alanine Transaminase / Q000097:blood; D000998:Antiviral Agents / Q000627:therapeutic use*; D004279:DNA, Viral / Q000097:blood; D004305:Dose-Response Relationship, Drug; D024882:Drug Resistance, Viral; D005260:Female; D006513:Hepatitis B e Antigens / Q000032:analysis; D006515:Hepatitis B virus / Q000187:drug effects*; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D019259:Lamivudine / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D063065:Organophosphonates / Q000008:administration & dosage*; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use*; D016896:Treatment Outcome
D000998:Antiviral Agents; D004279:DNA, Viral; D006513:Hepatitis B e Antigens; D063065:Organophosphonates; D018894:Reverse Transcriptase Inhibitors; D019259:Lamivudine; D000410:Alanine Transaminase; D000225:Adenine; C106812:adefovir dipivoxil