In therapy of chronic hepatitis B, there are new and exciting developments in antivirals such as nucleotide analogues. Adefovir dipivoxil is an oral prodrug of adefovir, a nucleotide analogue of adenosine monophosphate. This agent has a potent in vitro and in vivo effect against herpes virus, retroviruses, and hepadnaviruses. In the hepatitis B virus (HBV) setting, adefovir dipivoxil inhibits both the wild type and lamivudine-resistant HBV strains. The safety profile of adefovir dipivoxil 10 mg is excellent, but higher doses can produce renal tubular damage, particularly when the drug is used for prolonged therapy. Adefovir dipivoxil is an important new addition to the current first-line treatments for HBeAg positive and negative chronic hepatitis B, as well as being rescue therapy for lamivudine-resistant HBV strains. It is also licensed for use in adults with decompensated liver disease, as well as compensated liver disease where there is evidence of active viral replication, persistently elevated serum alanine aminotransferase levels and active liver inflammation and fibrosis. However, a longer follow-up is needed to establish the long term safety and efficacy of adefovir dipivoxil in patients with chronic HBV infection.
Adenine/adverse effects/*analogs & derivatives/*therapeutic use ; Antiviral Agents/adverse effects/*therapeutic use ; Hepatitis B, Chronic/*drug therapy ; Humans ; Liver Diseases/drug therapy ; *Phosphonic Acids

BACKGROUND/AIMS: We investigated the durability of the biochemical and virologic responses after adefovir (ADV) discontinuation in lamivudine-resistant (LMV-R) chronic hepatitis B (CHB) patients, and the outcomes of ADV discontinuation compared to that of ADV maintenance. METHODS: The indication for ADV treatment cessation was an undetectable level of hepatitis B virus (HBV) DNA documented on two occasions at least 6 months apart. All patients received additional ADV for at least 12 months after the confirmation of undetectable HBV DNA (Cobas TaqMan PCR assay, <70 copies/mL). Of 36 patients who had a sufficient ADV therapeutic effect, 19 discontinued ADV treatment, while the others maintained it. A virologic rebound was arbitrarily defined as the redetection of HBV DNA at a level higher than 105 copies/mL. RESULTS: In the ADV discontinuation group, ADV treatment and additional therapy were administered for medians of 33 months (range, 12-47 months) and 18 months, respectively. The patients were followed for a median of 12 months (range, 3-30 months) after ADV cessation. During that period, 18 of 19 patients (95%) experienced viral relapse. Viral rebound was observed in six patients (32%). However, 12 of 18 patients (67%) exhibited serum HBV DNA levels of less than 105 copies/mL. Biochemical relapses were observed in four of the six patients with viral rebound. In the ADV maintenance group, patients were treated for a median of 53 months (range, 31-85 months), and 9 patients (53%) experienced viral breakthrough. CONCLUSIONS: During short-term follow-up after ADV discontinuation, most patients (95%) exhibited viral relapse, whereas and viral breakthrough occurred in about half of patients (53%) maintained on ADV therapy. Therefore, the durability of virologic response after ADV discontinuation in LMV-R patients was unsatisfactory. In addition, and viral breakthrough was not infrequent in the ADV continuation group.
Adenine/*analogs & derivatives/therapeutic use ; Adult ; Antiviral Agents/*therapeutic use ; DNA, Viral/analysis ; Drug Resistance, Viral ; Female ; Follow-Up Studies ; Hepatitis B, Chronic/*drug therapy ; Humans ; Lamivudine/therapeutic use ; Male ; Middle Aged ; Phosphonic Acids/*therapeutic use ; Recurrence ; Risk Factors

During the past decade, major breakthroughs have been achieved in treatment of chronic hepatitis B. Currently, three therapeutic agents are approved for chronic hepatitis B: interferon-alpha, lamivudine and adefovir dipivoxil. In patients with HBeAgpositive chronic hepatitis B, all of these drugs achieve HBeAg loss (24-33%) and anti-HBe seroconversion (12-30%) rates that are superior to those observed in untreated controls. Interferon-alpha has several drawbacks, such as the parenteral administration and the development of frequent and potentially serious side effects. Lamivudine is a safe drug with rare and generally mild side effects. Lamivudine induces an initial virological remission in 70-90% of patients, but only 30-40% of patients remain in remission after the third year due to progressively increasing viral resistance. The main advantage of adefovir dipivoxil is the rare emergence of resistance, which has been identified in less than 2% of patients at 2 yr of treatment. Adefovir is also effective against lamivudine-resistant strains. This review will focus on the natural history and recently gained knowledge on the treatment of chronic hepatitis B.
Adenine/*analogs & derivatives/therapeutic use ; Antiviral Agents/*therapeutic use ; Hepatitis B/*drug therapy ; Humans ; Interferon-alpha/therapeutic use ; Lamivudine/therapeutic use ; Phosphonic Acids/therapeutic use ; Reverse Transcriptase Inhibitors/therapeutic use

BACKGROUND/AIMS: Anti-viral therapy using hepatitis B immune globulin and lamivudine could not prevent HBV recurrence after liver transplantation (LT) completely. Adefovir dipivoxil is a acyclic nucleotide phosphate analogue and known to have potent anti-HBV effect. In this study, we analyzed the therapeutic effect of adefovir for recurrent or de novo HBV infection after LT. METHODS: From December 2002 to October 2004, adefovir was administered in 12 post-LT patients of HBV infection (11 recurrent and 1 de novo infection). In these patients, lamivudine and other combined therapies were used before the introduction of adefovir. Thereafter, adefovir combined with lamivudine was administered to all patients. RESULTS: The duration of adefovir administration was 5.5-18 (median, 15.5) months. The median values of serum AST and ALT levels were significantly reduced from 86+/-80 IU/L and 140+/-103 IU/L, respectively before the adefovir administration to 42+/-19 IU/L and 38+/-33 IU/L after 2 months of administration. This trend of improved liver function persisted throughout the follow-up period. HBeAg seroconversion was achieved in 4 of 10 patients (40%) and HBsAg seroconversion was observed in 1 of 10 patients (10%). HBV DNA levels have decreased to undetectable levels by hybridization assay in 6 of 7 patients within the first 2 months of therapy. Nephrotoxicity and hypophosphatemia were not found in all of these patients. CONCLUSIONS: Based on this preliminary result, adefovir dipivoxil seems to be an effective and safe antiviral agent leading to viral inhibition and clinical improvement in post-LT patients with recurrent or de novo HBV infection.
Adenine/administration & dosage/*analogs & derivatives ; Adult ; Antiviral Agents/*administration & dosage ; Drug Therapy, Combination ; English Abstract ; Female ; Hepatitis B, Chronic/*drug therapy ; Humans ; Lamivudine/administration & dosage ; *Liver Transplantation ; Male ; Middle Aged ; Phosphonic Acids/*administration & dosage ; Recurrence ; Reverse Transcriptase Inhibitors/administration & dosage

BACKGROUND/AIMS: Adefovir dipivoxil is effective in patients with lamivudine-resistant hepatitis B virus (HBV). However, little is known about its role in Korean patients with decompensated liver cirrhosis. We retrospectively evaluated the efficacy and safety of adefovir dipivoxil in patients with decompensated liver cirrhosis with lamivudine resistance, and we compared this to the patients having compensated liver disease. METHODS: The patients with lamivudine-resistant chronic liver disease were enrolled and they received adefovir dipivoxil 10 mg daily. The clinical course and the biochemical and virological response of the decompensated cirrhosis group were compared with those of the patients with compensated liver disease group. RESULTS: One-hundred and one patients (the decompensated cirrhosis group, n=53; the compensated liver disease group, n=48) were evaluated. During the following up, 13 patients in the decompensated group and 4 patients in the compensated group dropped out of the treatment (P=0.011). After adefovir treatment, the proportion of patients with serum HBV DNA below 0.5 pg/mL in the decompensated group was less than that in the compensated group (50.9% vs. 83.3%, P=0.001), but the rates of normalized ALT, HBeAg loss and HBeAg seroconversion did not differ. The change of the Child-Pugh score in the decompensated group was 9.1 +/- 1.8 to 6.9 +/- 1.6 (P<0.001). The biochemical response in decompensated group was slower than that in the compensated group. Renal toxicity was not observed in either group. CONCLUSIONS: These results suggest that adefovir dipivoxil would be an effective and safe treatment for patients with decompensated liver cirrhosis with lamivudine resistance, but its effect might be limited and slower for decompensated cirrhosis.
Adenine/*analogs & derivatives/therapeutic use ; Adult ; Aged ; Antiviral Agents/*therapeutic use ; *Drug Resistance, Viral ; English Abstract ; Female ; Hepatitis B/complications/*drug therapy ; Humans ; Lamivudine/*therapeutic use ; Liver Cirrhosis/*virology ; Male ; Middle Aged ; Phosphonic Acids/*therapeutic use

BACKGROUND/AIMS: Add on adefovir (ADV) to ongoing lamivudine (LAM) has been recommended as a standard therapy for the treatment of LAM resistance. In the past, switch to ADV monotherapy was suggested as an option for the treatment of LAM resistance, leading to frequent development of ADV resistance. However, ADV monotherapy has been still used in LAM-resistant patients because of low cost in Korea. The aims of this study were to evaluate the virologic response and virologic breakthrough during adding on LAM in LAM-resistant patients receiving ADV monotherapy. METHODS: The study population comprised 99 patients with LAM-resistance. We divided them into 3 groups (Group 1: switch to ADV monotherapy, N=58, Group 2: add on ADV to ongoing LAM, N=25, Group 3: add on LAM to ADV monotherapy, N=16). HBV DNA levels were assessed at baseline and every 3 months during therapy. Serum HBV DNA levels were measured by bDNA assay or the COBAS TaqMantrade mark HBV test. RESULTS: The median treatment duration for group 1, group 2, and group 3 was 42.0, 20.6, and 31.8 (18.7 mon. of ADV+13.1 mon. of LAM) months, respectively. Cumulative rate of virologic breakthrough in group 1 was 5.2%, 19.0%, and 25.9% at 12, 24, and 36 months of treatment, respectively. Virologic breakthrough was not detected in group 2 and group 3 (p=0.016, group 1 vs. group 2 or 3). In group 3, median serum HBV DNA levels were 4.22 log10 copies/mL prior to LAM administration. Median serum HBV DNA changes from baseline (log10 copies/mL) were -0.91, -1.93, -1.87 and -1.74 at week 12, 24, 36 and 48, respectively. CONCLUSIONS: Later add on LAM to ADV monotherapy prevented the development of ADV resistance in patients with LAM resistance effectively, comparable to ADV add on to continuing LAM therapy.
Adenine/*analogs & derivatives/therapeutic use ; Adult ; Antiviral Agents/*pharmacology ; DNA, Viral/blood ; Drug Resistance, Viral ; Drug Therapy, Combination ; Female ; Hepatitis B e Antigens/blood ; Hepatitis B, Chronic/*drug therapy ; Humans ; Lamivudine/*therapeutic use ; Male ; Middle Aged ; Phosphonic Acids/*therapeutic use

No abstract available.
Adenine/*analogs & derivatives/therapeutic use ; Antiviral Agents/*therapeutic use ; Drug Resistance, Viral/genetics ; Hepatitis B virus/genetics ; Hepatitis B, Chronic/*drug therapy ; Humans ; Mutation ; Phosphonic Acids/*therapeutic use ; Treatment Outcome

No abstract available.
Adenine/*analogs & derivatives/therapeutic use ; Antiviral Agents/*therapeutic use ; DNA, Viral/analysis ; Drug Resistance, Viral ; Drug Therapy, Combination ; Hepatitis B, Chronic/*drug therapy ; Humans ; Lamivudine/*therapeutic use ; Phosphonic Acids/*therapeutic use

BACKGROUND/AIMS: The aim of this study was to elucidate the antiviral efficacy of lamivudine (LMV)-adefovir (ADV) combination therapy in chronic hepatitis B patients who showed resistance to LMV and ADV consecutively. METHODS: A retrospective review was performed in eighteen patients with chronic hepatitis B who developed virologic breakthroughs during LMV-ADV sequential mono-therapy and treated with LMV-ADV combination therapy. RESULTS: The median duration of follow up was 17 months (range, 6-27) after the start of LMV-ADV combination therapy. Mean HBV DNA level in log10 IU/mL was 6.08+/-0.95, 4.05+/-1.66, 3.17+/-1.58, 3.18+/-2.16, and 2.35+/-1.52 at 0, 3, 6, 12, and 24 months, respectively. Sixteen patients (88.9%) showed HBV DNA reduction below detection limit (<20,000 IU/mL). HBeAg seroconversion was observed in one patient (7.1%) after 8 months of combination therapy. Virologic breakthrough occurred in only one patient after 21 months of combination therapy. Viral rebound occurred in two patients at 12 months and 14 months of combination therapy. Normalization of serum ALT was achieved in twelve patients (66.7%). Primary non-response was observed in two cases (11.1%). CONCLUSIONS: LMV-ADV combination treatment was effective in 88.9% of patients with resistance to LMV and ADV in a short-term follow up. It may be applied as a bridge therapy until another effective antiviral regimen becomes available.
Adenine/*analogs & derivatives/therapeutic use ; Adult ; Antiviral Agents/*therapeutic use ; DNA, Viral/analysis ; Drug Resistance, Viral ; Drug Therapy, Combination ; Female ; Genotype ; Hepatitis B, Chronic/*drug therapy ; Humans ; Lamivudine/*therapeutic use ; Male ; Middle Aged ; Phosphonic Acids/*therapeutic use ; Time Factors

BACKGROUNDS/AIMS: Continuation of lamivudine therapy is controversial for patients with chronic hepatitis B when viral breakthrough occurs. Moreover, the effect of continuous lamivudine therapy is unknown in patients with acute exacerbation after viral breakthrough. We assessed clinical course of acute exacerbation after viral breakthrough in patients who continued and discontinued lamivudine therapy. METHODS: Medical records of 109 patients with viral breakthrough during lamivudine therapy were reviewed. Of 40 patients with acute exacerbation (ALT level > 5 x ULN), adefovir dipivoxil was unavailable in 38 patients. These 38 patients (mean age 42.6 years; male/female, 34/6) were divided into continuation (n=21) and discontinuation (n=17) groups. Clinical courses of the 2 groups were compared. RESULTS: During follow-up period (mean, 27 months; range, 6-60 months), ALT levels decreased to < 2 x ULN in 11 patients (52%) of continuation group and 9 patients (53%) of discontinuation group, varied from 2 x to 5 x ULN in 9 (43%) and 5 (29%), respectively, and increased to > 5 x ULN in 1 (5%) and 3 (18%), respectively, with no statistical significance (P=.417). CONCLUSIONS: When acute exacerbation of ALT levels occurs after viral breakthrough during lamivudine administration in patients with compensated chronic hepatitis B, continuation of lamivudine may have no advantage over discontinuation.
Phosphonic Acids/therapeutic use ; Middle Aged ; Male ; Lamivudine/*administration & dosage ; Humans ; Hepatitis B, Chronic/drug therapy/enzymology/*virology ; Hepatitis B virus/*isolation & purification ; Female ; Antiviral Agents/*administration & dosage ; Alanine Transaminase/blood ; Aged ; Adult ; Adenine/analogs & derivatives/therapeutic use ; Acute Disease