pyrimidinones and entecavir

The incidence of acute B hepatitis is decreasing due to socioeconomical changes and the implementation of vaccination programs. Nevertheless it is potentially severe, causing approximately 30% of acute liver failures in Spain. Pharmacological treatment of acute B hepatitis has become a matter of issue over the last decade. This text offers a review of the published data and international guidelines. Most published studies have a low methodological quality and lamivudine was used as treatment in all of them. A survival improvement with prompt treatment has been shown in acute liver injury and probably in severe acute hepatitis (total bilirubin>10mg/dl and INR>1.5). International guidelines support treatment in these cases, but there is no consensus on the drug to use or the length of treatment.

Topics: Acute Disease; Adenine; Antiviral Agents; Guanine; Hepatitis B; Humans; Lamivudine; Nucleosides; Organophosphonates; Practice Guidelines as Topic; Pyrimidinones; Spain; Telbivudine; Tenofovir; Thymidine; Treatment Outcome

The optimal oral anti-viral agent to use in patients with decompensated HBV cirrhosis remains unclear.. We performed a meta-analysis of the oral nucleos(t)ide analogues in patients with decompensated HBV cirrhosis.. One year efficacy and safety outcomes in 22 studies published in English between '95 and 2010 were analysed.. Substantial heterogeneity was noted in the inclusion/exclusion criteria, controls, and sensitivity of the HBV DNA assay used. Pooled 1-year data showed benefit favouring lamivudine (LAM) vs. untreated controls for Child-Turcotte-Pugh (CTP) score improvement by ≥2 (OR: 117 (15 921), P ≤ 0.0001) and transplant-free survival (OR: 3.2 (1.2, 9), P = 0.022). Adefovir (ADV) led to undetectable HBV DNA at 1-year in 41% compared to 83% with LAM and 80% with entecavir (ETV). Overall, 1-year transplant-free survival rates varied from 78% with LAM to 95% and 94% with Tenofovir (TDF) and Telbivudine (TBV), respectively. The 1-year incidence of drug resistant HBV was 0% with ADV, ETV and TDF and 11% with LAM although TBV was associated with a 29% incidence at 2 years. Drug-related adverse events were infrequently reported.. All the oral anti-viral agents were associated with improved virological, biochemical and clinical parameters at 1-year. However, the efficacy of lamivudine and telbivudine is limited by drug resistance, and adefovir is limited by its potency and slower onset of action. Additional studies of tenofovir and entecavir are needed to determine the optimal agent(s) for treatment naïve patients and in those with drug-resistant decompensated HBV cirrhosis.

Topics: Adenine; Administration, Oral; Adult; Antiviral Agents; Drug Resistance, Viral; Drug Therapy, Combination; Guanine; Hepatitis B; Hepatitis B virus; Hepatitis B, Chronic; Humans; Lamivudine; Liver Cirrhosis; Nucleosides; Organophosphonates; Pyrimidinones; Randomized Controlled Trials as Topic; Reverse Transcriptase Inhibitors; Telbivudine; Tenofovir; Thymidine; Time Factors; Treatment Outcome; Viral Load

HBeAg seropositivity is a marker for active viral replication. In the natural history of chronic hepatitis B infection, HBeAg marks the first two of the four phases, namely the immune tolerant phase and the immune clearance phase, and is associated with highly replicative activity of the hepatitis B virus (HBV). Most HBV consensus reports and guidelines recommend antiviral therapy if the immune clearance phase is prolonged and if there is evidence of significant necroinflammation and fibrosis. Two main types of antiviral agents have been approved for treating patients in the immune clearance phase: interferon and nucleos(t)ide analogues (NUCs). The endpoints of therapy are viral suppression with HBeAg seroconversion, undetectable serum HBV DNA, normalization of serum alanine transaminase and improvement in the histological necroinflammatory and fibrosis scores. The ultimate goal of therapy is to obtain clinical benefit for the patient by reducing complications including hepatocellular carcinoma (HCC). The choice between interferon-based immune modulators or NUCs that target the HBV DNA polymerase must be carefully weighed on an individual basis. Therapy with NUCs is often preferred by doctors and patients because it is easy to administer, with predictable efficacy and minimal side-effects. In specific patient subgroups such as those with decompensated disease, poor predictors of response or lack of response to interferon-based therapy and/or significant comorbidities that cannot tolerate interferon-induced side effects, NUCs therapy is the obvious choice. Entecavir and tenofovir are the treatments of choice because their efficacy and safety profile are better than lamivudine, adefovir and telbivudine. More importantly, there is a minimal risk of drug resistance during long-term therapy with these agents.

Topics: Adenine; Antiviral Agents; Guanine; Hepatitis B e Antigens; Hepatitis B virus; Hepatitis B, Chronic; Humans; Lamivudine; Nucleosides; Organophosphonates; Pyrimidinones; Telbivudine; Tenofovir; Thymidine; Treatment Outcome

Chronic hepatitis B virus (HBV) infections remain a major public health problem worldwide. According to World Health Organization estimates, more than 300 million people are chronically infected and exposed to the risk of developing severe complications including cirrhosis and hepatocellular carcinoma (HCC). Major progress in the treatment of chronic hepatitis B (CHB) has been made during the last decade with the development of antivirals that inhibit viral polymerase activity. Antiviral drug resistance is an important factor in determining the success of long-term therapy for CHB. The development of resistance to nucleoside analogues (NUCs) has been associated with exacerbations of liver disease. Sequential therapy increases the risk of the emergence of multidrug resistance. The selection of a potent antiviral with a high barrier to resistance as a first-line therapy provides the best chance of achieving long-term treatment goals and should be used whenever possible. This has led to a significant decrease in drug resistance in countries where this strategy is affordable. However, the barrier to resistance of a given antiviral agent is influenced by the genetic barrier, drug potency, patient adherence, pharmacological barrier, viral fitness, the drug mechanisms of action and cross resistance. Furthermore, because of specific viral kinetics, prolonged treatment with NUCs does not result in the clearance of the viral genome from the infected liver. It is therefore important to continue research to identify new viral and immune targets and develop novel antiviral strategies for controlling viral replication as well as preventing drug resistance and its complications in the long term.

Topics: Adenine; Antiviral Agents; Capsid; Clinical Protocols; Drug Resistance, Viral; Guanine; Hepatitis B virus; Hepatitis B, Chronic; Humans; Lamivudine; Nucleosides; Organophosphonates; Pyrimidinones; Telbivudine; Tenofovir; Thymidine; Virus Internalization; Virus Replication

The combination of antiretroviral (ARV) therapies introduced at the end of the 1990s profoundly changed the natural history of human immunodeficiency virus (HIV) infection. Liver diseases are one of the three primary causes of 'non-AIDS-related' death in people living with HIV for three reasons: the high prevalence of hepatotropic viral co-infections, the hepatotoxicity of ARV drugs and new emerging liver diseases, including nodular regenerative hyperplasia and hepatitis E virus infection. The impact of HIV infection on the natural history of hepatitis C virus (HCV) or hepatitis B virus (HBV)/HIV co-infection has markedly changed in the past few decades with the progress made in ARV treatment and the improved definition of therapeutic strategies for HCV or HBV. Initially, HIV had a negative impact on hepatotropic infections. Today, HIV does not appear to significantly modify the natural history of HCV and HBV infection. This is associated with fair immune restoration, viral suppression associated with analogues having dual activity against HBV and HIV and with the increasing efficacy of antiviral treatments against HCV. A significant decline is expected in the morbidity and mortality associated with chronic liver infection in co-infected patients. Nevertheless, today, there are three major issues: (i) improving preventive measures including vaccination and risk reduction; (ii) screening patients infected with HBV or HCV and evaluating the impact of chronic infection on the liver and finally; (iii) early screening of hepatocellular carcinoma whose occurrence is higher and that evolves more rapidly in co-infected than in mono-infected patients.

Topics: Adenine; Antiviral Agents; Deoxycytidine; Disease Progression; Drug Therapy, Combination; Emtricitabine; Guanine; Hepatitis B; Hepatitis C; Hepatitis Viruses; HIV Infections; Humans; Interferon-alpha; Lamivudine; Nucleosides; Organophosphonates; Pyrimidinones; Telbivudine; Tenofovir; Thymidine

Treatment of chronic hepatitis B is still challenging. Lots of parameters are needed to be considered before and during the therapy. There are several possible endpoints and their durability is very much variable. Patients with HBeAg-positive and HBeAg-negative hepatitis B need treatment. Two different strategies are available. Interferon-based therapy is a limited treatment, which might result in a sustained immune response in about one third of the patients, leading to an induced remission, sometimes years after the end of the treatment. According to the other strategy a continuous, indefinite oral nucleoside/nucleotide analogue (NA) treatment is administered to maintain a remission. However, relapse is rather frequent after the cessation of this therapy. During the long-term NA treatment drug resistance can lead to the loss of antiviral effect. Three first-line drugs are recommended, pegylated interferon alfa-2a, entecavir and tenofovir. If there is no contraindication to interferon, it is worth trying to achieve immune control and an induced remission. In patients, who do not respond to interferon, a sequential NA therapy is indicated.

Topics: Adenine; Antiviral Agents; DNA, Viral; Drug Therapy, Combination; Guanine; Hepatitis B virus; Hepatitis B, Chronic; Humans; Interferon alpha-2; Interferon-alpha; Lamivudine; Nucleosides; Nucleotides; Organophosphonates; Polyethylene Glycols; Pyrimidinones; Recombinant Proteins; Telbivudine; Tenofovir; Thymidine; Treatment Outcome

It is estimated there are 350-400 million people worldwide chronically infected with HBV. Many of these are women and of reproductive age. As such, they may face therapeutic decisions regarding antiviral therapy and the implication this may have on future or current pregnancies. This article reviews the data of all antivirals licensed for use against hepatitis B infection regarding teratogenicity, carcinogenicity, clinical experience during pregnancy, placental transfer and excretion in breast milk.

Topics: Adenine; Antiviral Agents; Breast Feeding; Female; Guanine; Hepatitis B; Hepatitis B virus; Hepatitis B, Chronic; Humans; Interferon-alpha; Lamivudine; Nucleosides; Organophosphonates; Placenta; Pregnancy; Pregnancy Complications, Infectious; Pyrimidinones; Telbivudine; Tenofovir; Thymidine

Most viral diseases, with the exception of those caused by human immunodeficiency virus, are self-limited illnesses that do not require specific antiviral therapy. The currently available antiviral drugs target 3 main groups of viruses: herpes, hepatitis, and influenza viruses. With the exception of the antisense molecule fomivirsen, all antiherpes drugs inhibit viral replication by serving as competitive substrates for viral DNA polymerase. Drugs for the treatment of influenza inhibit the ion channel M(2) protein or the enzyme neuraminidase. Combination therapy with Interferon-α and ribavirin remains the backbone treatment for chronic hepatitis C; the addition of serine protease inhibitors improves the treatment outcome of patients infected with hepatitis C virus genotype 1. Chronic hepatitis B can be treated with interferon or a combination of nucleos(t)ide analogues. Notably, almost all the nucleos(t) ide analogues for the treatment of chronic hepatitis B possess anti-human immunodeficiency virus properties, and they inhibit replication of hepatitis B virus by serving as competitive substrates for its DNA polymerase. Some antiviral drugs possess multiple potential clinical applications, such as ribavirin for the treatment of chronic hepatitis C and respiratory syncytial virus and cidofovir for the treatment of cytomegalovirus and other DNA viruses. Drug resistance is an emerging threat to the clinical utility of antiviral drugs. The major mechanisms for drug resistance are mutations in the viral DNA polymerase gene or in genes that encode for the viral kinases required for the activation of certain drugs such as acyclovir and ganciclovir. Widespread antiviral resistance has limited the clinical utility of M(2) inhibitors for the prevention and treatment of influenza infections. This article provides an overview of clinically available antiviral drugs for the primary care physician, with a special focus on pharmacology, clinical uses, and adverse effects.

Topics: Acyclovir; Adenine; Amantadine; Antiviral Agents; Comorbidity; Drug Therapy, Combination; Foscarnet; Ganciclovir; Guanine; Hepatitis; Hepatitis B, Chronic; Hepatitis C; Herpesviridae Infections; HIV Infections; Humans; Influenza, Human; Interferons; Lamivudine; Nucleosides; Oligopeptides; Organophosphonates; Oseltamivir; Proline; Protease Inhibitors; Pyrimidinones; Ribavirin; Telbivudine; Thymidine; Valacyclovir; Valganciclovir; Valine; Virus Replication; Zanamivir

Long-term therapy with oral nucleoside/nucleotide analogues (NAs) is a favoured approach to the treatment of patients with chronic hepatitis B (CHB); however, all oral agents currently approved for the treatment of such patients are associated with some risk for drug resistance. This can lead to a rebound in HBV levels and, eventually, progressive liver disease. Combination therapy is one strategy that has the potential for enhanced antiviral effects and diminished or delayed resistance. The disadvantages of combination therapy include increased cost, the potential for drug interactions and increased toxicity. Additional therapeutic efficacy from combination therapy has not been demonstrated in clinical trials of HBV, and this approach might be less relevant now that potent NAs with excellent drug resistance profiles are available. However, it might be possible to identify subsets of patients (for example, those with extremely high viraemia or low baseline alanine aminotransferase levels) who derive added benefit from combination therapy. This review examines efficacy and resistance data for new low resistance oral NAs and clinical experience to date with de novo combination therapy in patients with CHB. The application of combination therapy in select populations of patients with CHB is also discussed.

Topics: Adenine; Administration, Oral; Antiviral Agents; Drug Resistance, Viral; Drug Therapy, Combination; Guanine; Hepatitis B, Chronic; Humans; Nucleosides; Organophosphonates; Pyrimidinones; Telbivudine; Tenofovir; Thymidine; Treatment Outcome

Chronic infection with hepatitis B virus (HBV) is a major global health problem and an important cause of morbidity and mortality from sequelae of liver cirrhosis and hepatocellular carcinoma. In the past decades, better understanding of the natural history and immunopathogenesis of chronic HBV infection and of the development of many powerful antiviral agents has allowed us to improve therapeutic efficacy. Among these agents, nucleos(t)ide analogs are important and potent viral suppressors. However, when administered alone, they are not able to permanently eradicate HBV, and long-term maintenance therapy is required for therapeutic efficacy. Additionally, prolonged treatment is frequently associated with the emergence of drug-resistant HBV mutants. Before an 'ideal' drug(s), or drug combination, with optimal antiviral efficacy and negligible rates of drug resistance becomes available, the on-treatment monitoring approach using serum HBV DNA level as a predictor for therapeutic efficacy and drug resistance is useful. However, most countries in the Asia-Pacific region have low income economies, insufficient medical care systems, and low awareness of the disease among the general population and government officers. The easy approach of the road-map concept using an affordable drug to treat chronic HBV infection is more important in this region. There is already evidence that the long-term outcomes of chronic HBV infection can be improved under well-managed antiviral therapy. Profound and long-lasting suppression of HBV replication, either maintained on-therapy or sustained after stopping therapy, has been identified as the key determinant for achieving the goals of therapy, for reducing liver damage, and for preventing development of cirrhosis and/ or hepatocellular carcinoma.

Topics: Adenine; Antiviral Agents; Asia; Biomarkers; DNA, Viral; Drug Monitoring; Drug Resistance, Viral; Guanine; Hepatitis B virus; Hepatitis B, Chronic; Humans; Lamivudine; Nucleosides; Organophosphonates; Pyrimidinones; Telbivudine; Tenofovir; Thymidine; Time Factors; Treatment Outcome; Viral Load; Virus Replication

The ultimate goal of treatment is suppression of viral replication to undetectable HBV-DNA levels prior to and after liver transplantation (LT) to prevent infection of the newly transplanted liver. Most published data are available from therapy with lamivudine (LAM) in pre- and post-transplant HBV patients. Add-on therapy with adefovir dipivoxil (ADV) in pre-transplant LAM-resistant patients has been shown to represent an effective antiviral strategy leading to hepatic recompensation in many cases and, eventually, removal from the waiting list. Newer nucleos(t)ide analogues such as entecavir, tenofovir and telbivudine have shown lower resistance rates than LAM and more antiviral potency in studies in the non-transplant setting. Combined hepatitis B immune globulin (HBIG) and nucleos(t)ide analogue therapy have been widely adopted as the most effective treatment strategy against recurrent HBV disease after LT. Many programs have evaluated lower doses or a shorter duration of HBIG and intramuscular versus intravenous routes of administration. Active immunisation using recombinant HBV vaccines, including the S, pre-S1 and pre-S2 regions, and those with immunostimulatory adjuvants, seem to be more immunogenic than the currently available vaccines and have been used in studies to replace HBIG. Furthermore, it has been shown that immune memory against HBV can be adoptively transferred from organ donors to transplant recipients. Nucleos(t)ide analogue combination therapies might provide an alternative to the current treatment paradigm with costly HBIG; however, experience with this new treatment regimen is very limited and controlled clinical studies are urgently warranted to investigate its safety and efficacy and to determine which nucleos(t)ide analogue combinations will be the most promising in the long term after LT.

Topics: Adenine; Antiviral Agents; Drug Therapy, Combination; Guanine; Hepatitis B; Hepatitis B Vaccines; Humans; Immunoglobulins; Lamivudine; Liver Transplantation; Nucleosides; Organophosphonates; Pyrimidinones; Telbivudine; Tenofovir; Thymidine

Antiviral therapy is aimed to persistently suppress hepatitis B virus (HBV) to prevent liver complications and improve survival and long-term administration of nucleos(t)ide analogues represents an attractive treatment strategy. Five oral analogues are available, and all inhibit viral replication in most patients during the first year of therapy. By converse, long-term monotherapy is associated to high rates of resistance with lamivudine, and intermediate rates with Adefovir and Telbivudine. Third-generation analogues such as Entecavir and Tenofovir may efficiently inhibits viral replication in most patient for many years as they couple potency and high genetic barrier. In patients developing drug-resistance, specific rescue protocols based upon 'early add-on' have been developed to rapidly and efficiently control viral replication. In cirrhotics, long-term effective analog-based therapy prevented clinical decompensation for many years, but not liver cancer development. Long-term administration of NUCs, either as a monotherapy or as a sequential combination, inhibits HBV replication in most HBeAg-negative patients for at least 5 years, preventing clinical decompensation in cirrhotics.

Topics: Adenine; Antiviral Agents; Drug Resistance, Viral; Guanine; Hepatitis B e Antigens; Hepatitis B, Chronic; Humans; Lamivudine; Nucleosides; Organophosphonates; Pyrimidinones; Telbivudine; Tenofovir; Thymidine; Virus Replication

Chronic hepatitis B is a serious disease both worldwide and in the United States. There are two types of drugs available to treat chronic hepatitis B virus (HBV) infection: interferons that boost the immune system, and antiviral or nucleoside analogues that are designed to interfere with HBV DNA to prevent its replication. This review focuses on nucleoside antivirals, namely lamivudine, entecavir and telbivudine, which are widely prescribed for patients with the disease, particularly lamivudine. Additionally, current Food and Drug Administration-approved nucleoside antivirals for hepatitis B will be briefly highlighted. Comparisons are performed based on previous clinical trials from primary sources. Treatments with entecavir and telbivudine are compared with lamivudine treatment in regard to pharmacotherapy, resistance and cost-effectiveness. Outcomes varied depending on each trial, but the main findings were more favorable for entecavir and telbivudine treatments than for lamivudine treatment. It was concluded that entecavir treatment is associated with better outcomes than lamivudine in the three aspects studied. Similarly, telbivudine showed more improvements than lamivudine in all three areas. Concomitant pharmacotherapy, especially in lamivudine-refractory patients, demonstrated significant improvement in the management of chronic hepatitis B. Furthermore, the availability of hepatitis B vaccines should enable us to prevent the occurrence of the disease.

Topics: Antiviral Agents; Cost-Benefit Analysis; Drug Resistance, Viral; Guanine; Hepatitis B e Antigens; Hepatitis B, Chronic; Humans; Lamivudine; Nucleosides; Pyrimidinones; Telbivudine; Thymidine

Substantial progress has been made in the treatment of chronic hepatitis B during the past decade. Nucleos(t)ide analogues are now widely used due to their convenience, less side effects, and considerable response rates. However, development of antiviral resistance is a major problem being considered as the most important factor for the treatment failure. Viral breakthrough associated with selection of antiviral-resistant hepatitis B virus (HBV) is usually followed by biochemical breakthrough, clinical deterioration, and even progressive liver failure. Therefore, appropriate management of antiviral resistance is critical for improving treatment outcomes. Strategies for the management of antiviral-resistant chronic HBV infection are described herein considering recently published guidelines. Lamivudine/telbivudine resistance can be managed by adding adefovir. Switching to adefovir or entecavir is also a viable option. However, careful follow-up of viral load is mandatory to detect any primary or secondary treatment failure in case of sequential monotherapy. Interferon or peg-interferon therapy can also be considered in case of young patients with compensated liver disease. For adefovir resistance, lamivudine can be added, but adding or switching to entecavir is a more reasonable option. Likewise, adding or switching to adefovir can be considered for entecavir resistance. Adding or switching to tenofovir needs to be considered upon availability. Experiences for clevudine resistance are still lacking, and need to be studied further upon the isolation of clinically resistant strains. To avoid emergence of resistant mutations, antiviral therapy should be initiated after careful balance of risk and benefit, and the most potent antiviral agent with the lowest resistance rate should be selected.

Topics: Adenine; Antiviral Agents; Arabinofuranosyluracil; Drug Resistance, Multiple, Viral; Guanine; Hepatitis B virus; Hepatitis B, Chronic; Humans; Lamivudine; Mutation; Nucleosides; Organophosphonates; Practice Guidelines as Topic; Pyrimidinones; Telbivudine; Thymidine; Treatment Outcome

Hepatitis B virus (HBV) infection is a worldwide public health problem. There are an estimated 350 million persons with chronic HBV infection that could progress to cirrhosis and hepatocarcinoma with nearly one million deaths per year. In the last few years the therapeutic options in chronic hepatitis B have increased and currently six treatments are authorized: standard interferon (IFN)-alpha, pegylated interferon-alpha (PEG-IFNalpha), lamivudine, adefovir, entecavir, and telbivudine. For the last 25 years, conventional IFNalpha has been used as the treatment of chronic hepatitis B (CHB) and currently PEG-IFNalpha is indicated due to its greater effectiveness. Both drugs are first line options for HBeAg(+) and HBeAg(-) CHB. The advantages of IFNalpha and PEG-IFNalpha are that these drugs are administered for a limited time period, they achieve a higher sustained response rate and do not induce HBV mutants with antiviral resistance. These drugs achieve greater HBeAG and HBsAG clearance due to their antiviral and immunomodulatory activity. PEG-IFNalpha induces sustained biochemical and virological response in approximately one third of patients with HBeAg(+) CHB. The best response to IFNalpha and PEG-IFNalpha is obtained in patients with elevated transaminase levels, moderate viral load and HBV genotypes A and B. The disadvantages of IFNalpha and PEG-IFNalpha are their adverse effects and contraindications. These drugs cannot be administered in patients with decompensated cirrhosis. The combination of nucleos(t)ide analogs with PEG-IFNalpha could achieve much higher sustained response rates; however, which treatment constitutes the most suitable therapeutic strategy requires investigation.

Topics: Adenine; Antiviral Agents; Clinical Trials as Topic; Drug Therapy, Combination; Genotype; Guanine; Hepatitis B; Hepatitis B e Antigens; Hepatitis B virus; Hepatitis B, Chronic; Humans; Interferon alpha-2; Interferon-alpha; Lamivudine; Multicenter Studies as Topic; Nucleosides; Organophosphonates; Polyethylene Glycols; Pyrimidinones; Randomized Controlled Trials as Topic; Recombinant Proteins; Telbivudine; Thymidine; Treatment Outcome

At least 4 nucleos(t)ide analogs have been approved for the treatment of chronic hepatitis B: lamivudine, adefovir dipivoxil, entecavir, and telbivudine. The introduction of these drugs has radically changed the treatment of this disease. The advantages of these drugs are their oral administration, excellent tolerability and efficacy in all types of chronic hepatitis B (compensated and decompensated disease). The limitations are the need for prolonged treatments, which hampers adherence and can cause selection of HBV strains resistant to distinct drugs. The resistance rate differs for each of the drugs. Nucleotide analogs such as adefovir and tenofovir are useful in patients resistant to nucleoside analogs such as lamivudine, entecavir and telbivudine and vice versa. In cases of resistance to one of these drugs, combined treatment is advised.

Topics: Adenine; Antiviral Agents; Clinical Trials as Topic; Deoxycytidine; Drug Resistance, Viral; Drug Therapy, Combination; Emtricitabine; Genotype; Guanine; Hepatitis B e Antigens; Hepatitis B virus; Hepatitis B, Chronic; Humans; Lamivudine; Multicenter Studies as Topic; Nucleosides; Organophosphonates; Pyrimidinones; Randomized Controlled Trials as Topic; Reverse Transcriptase Inhibitors; Telbivudine; Tenofovir; Thymidine; Treatment Outcome; Virus Replication

Chronic hepatitis B is still a major public health problem, aggravated by the growing phenomenon of immigration from areas with a high prevalence of infection with this virus. In the last few years, marked progress has been achieved in diagnostic methods, knowledge of the natural history of the disease and in therapeutic options, including liver transplantation, which has improved survival in these patients. These advances have been accompanied by an increase in the complexity of decision making. Six treatments have currently been approved for hepatitis B, including two interferon formulations--standard and pegylated--and four neucleos(t)ide analogs, lamivudine, adefovir, entecavir and telbivudine, as well as two further drugs that are used in patients coinfected with HIV, tenofovir and emtricitabine. However, none of the current treatments is able to eradicate the virus and consequently prolonged treatments are often required with the consequent risk of generating resistance. For this reason, as well as the heterogeneity of the natural history of the disease, there is a lack of consensus on the indications for treatment and the parameters in which treatment should be based, the most suitable drug or drug combination, and the criteria to be used to continue, modify or suspend treatment. Therefore, despite the enormous progress made, numerous questions remain that make the clinical management of these patients a major challenge.

Topics: Adenine; Antiviral Agents; Biopsy; Combined Modality Therapy; Deoxycytidine; Drug Resistance, Viral; Drug Therapy, Combination; Emtricitabine; Female; Genotype; Guanine; Hepatitis B Antibodies; Hepatitis B e Antigens; Hepatitis B virus; Hepatitis B, Chronic; Humans; Interferon-alpha; Lamivudine; Liver; Liver Transplantation; Male; Nucleosides; Organophosphonates; Pyrimidinones; Reverse Transcriptase Inhibitors; Telbivudine; Tenofovir; Thymidine; Virus Replication

Chronic hepatitis B virus infection affects approximately 10% of HIV-infected patients. There are an estimated 4 million patients with HIV/HBV coinfection. HIV infection has a deleterious effect on the natural history of chronic hepatitis B and increases the risk of progression to cirrhosis and terminal liver disease. Since the widespread use of highly active antiviral therapy (HAART), liver disease has emerged as one of the main causes of morbidity and mortality in HIV-positive patients. Therefore, all patients with HIV/HBV coinfection should be evaluated for treatment of hepatitis B, independently of the CD4 lymphocyte count. Six drugs are currently authorized for the treatment of chronic hepatitis B: standard interferon-alpha (2a and 2b), pegylated interferon alpha-2a, lamivudine, adefovir, entecavir and telbivudine. Other drugs with activity against HBV, such as tenofovir and emtricitabine, are used for the treatment of HIV infection. In patients not requiring HAART, treatment of hepatitis B should preferably consist of drugs without activity against HIV, such as pegylated interferon or adefovir. In contrast, in patients requiring HAART, a combination of drugs with activity against both viruses should be used, such as lamivudine, emtricitabine and tenofovir, with the aim of achieving maximal viral suppression and avoiding the development of resistance. Patients with HIV/HBV coinfection require periodic clinical and virological monitoring. Patients with cirrhosis should undergo ultrasonography and alphafetoprotein determination every 6 months for the early detection of hepatocellular carcinoma.

Topics: Adenine; Anti-HIV Agents; Antiretroviral Therapy, Highly Active; Antiviral Agents; Comorbidity; Deoxycytidine; Drug Resistance, Viral; Drug Therapy, Combination; Emtricitabine; Guanine; Hepatitis B; Hepatitis B Vaccines; Hepatitis B virus; HIV; HIV Infections; Humans; Interferon-alpha; Lamivudine; Nucleosides; Organophosphonates; Practice Guidelines as Topic; Pyrimidinones; Reverse Transcriptase Inhibitors; Telbivudine; Tenofovir; Thymidine; Virus Replication

Studies in the past decades have shown that active hepatitis B virus (HBV) replication is the key driver of liver injury and disease progression, and thus sustained viral suppression is of paramount importance in the management of chronic HBV infection. The nucleos(t)ide analogues lamivudine, adefovir, entecavir, telbivudine and tenofovir are potent inhibitors of HBV polymerase/reverse transcriptase activity and are highly effective in the suppression of HBV replication, but rarely eliminate the virus. Long-term therapy is usually required to achieve sustained hepatitis B e antigen seroconversion, HBV DNA suppression, ALT normalization and fibrosis reversal. Maintained long-term therapy has been demonstrated to significantly lower the rate of hepatic decompensation and development of cirrhosis or hepatocellular carcinoma. However, drug resistance is a serious risk on prolonged nucleos(t)ide analogue therapy, and this poses a critical challenge. Prevention and proper management of drug resistance are crucial to ensure long-term success.

Topics: Adenine; Adenine Nucleotides; Alanine Transaminase; Carcinoma, Hepatocellular; DNA, Viral; Drug Administration Schedule; Drug Resistance, Viral; Drug Therapy, Combination; Guanine; Hepatitis B e Antigens; Hepatitis B virus; Hepatitis B, Chronic; Humans; Lamivudine; Liver Cirrhosis; Liver Neoplasms; Nucleosides; Organophosphonates; Pyrimidinones; Randomized Controlled Trials as Topic; Reverse Transcriptase Inhibitors; Telbivudine; Thymidine; Treatment Outcome; Virus Replication

The practising clinician is currently faced with a number of effective treatment options for chronic hepatitis B, including two formulations of interferon (standard IFN and pegylated IFN) and five nucleos(t)ide analogues (lamivudine, adefovir, entecavir, telbivudine and tenofovir). Treatment strategies can be divided into those aiming for sustained response after discontinuation of therapy and those that need to be maintained by prolonged antiviral therapy. Sustained response is particularly achieved with interferon-based therapy, while treatment-maintained response can be achieved with long-term nucleos(t)ide analogue therapy in the majority of patients. Of currently available drugs for the treatment of chronic hepatitis B, PEG-IFN seems to result in the highest rate of off-treatment sustained response after a 1-year course of therapy. Sustained transition to the immune-control phase (inactive HBsAg carrier state) can be achieved in 30-35% of HBeAg-positive patients and 20-25% of HBeAg-negative patients. Loss of HBsAg has been observed in 11% of both HBeAg-positive and HBeAg-negative patients after 3-4 years. Since hepatitis B virus (HBV) genotype is an important predictor of response to PEG-IFN, determination of HBV genotype is essential in patients in whom sustained off-treatment response is pursued. Aiming for sustained response is of particular interest because many HBV-infected patients are in need of antiviral therapy at a young age and may otherwise require indefinite antiviral therapy.

Topics: Adenine; Antiviral Agents; DNA, Viral; Guanine; Hepatitis B e Antigens; Hepatitis B Surface Antigens; Hepatitis B virus; Hepatitis B, Chronic; Humans; Interferon alpha-2; Interferon-alpha; Lamivudine; Nucleosides; Organophosphonates; Polyethylene Glycols; Practice Guidelines as Topic; Pyrimidinones; Randomized Controlled Trials as Topic; Recombinant Proteins; Telbivudine; Tenofovir; Thymidine; Treatment Outcome

Topics: Adenine; Antiviral Agents; Clinical Trials as Topic; Drug Therapy, Combination; Follow-Up Studies; Guanine; Hepatitis B e Antigens; Hepatitis B Surface Antigens; Hepatitis B, Chronic; Humans; Interferon alpha-2; Interferon-alpha; Lamivudine; Nucleosides; Organophosphonates; Polyethylene Glycols; Pyrimidinones; Recombinant Proteins; Reverse Transcriptase Inhibitors; Telbivudine; Thymidine; Time Factors; Treatment Outcome

The long-term goals of therapy for chronic hepatitis B are to reduce serum HBV DNA to low or undetectable levels and ultimately reduce or prevent the development of cirrhosis and hepatocellular carcinoma.. To review the current treatment of chronic hepatitis B, with a focus on diagnosis and management of resistance and active management of suboptimal responses.. A systematic review of the literature, with a focus on recent guidelines, was undertaken.. Among the six drugs licensed for the treatment of chronic hepatitis B in the US, the preferred agents in 2008 will include entecavir, peginterferon alfa-2a, possibly telbivudine, and tenofovir following licensure. When using an oral agent, a major focus of management is on the selection of a drug with high potency and low rate of resistance, and active on-treatment management to optimize therapy. Preventing the sequelae of antiviral drug resistance and appropriate management when resistance is initially detected are also the major focus of current management. The addition of an antiviral agent that is not cross-resistant is critical to restore suppression of viral replication.. Newer agents and modified treatment strategies, especially using combination therapy, hold promise to optimize the management of patients with chronic hepatitis B by achieving the high potency and the lowest rate of resistance.

Topics: Adenine; Antiviral Agents; Carcinoma, Hepatocellular; Deoxycytidine; Drug Resistance, Viral; Emtricitabine; Guanine; Hepatitis B virus; Hepatitis B, Chronic; Humans; Interferon alpha-2; Interferon-alpha; Lamivudine; Liver Cirrhosis; Nucleosides; Organophosphonates; Polyethylene Glycols; Pyrimidinones; Recombinant Proteins; Reverse Transcriptase Inhibitors; Telbivudine; Tenofovir; Thymidine; Virus Replication

The ultimate goal in managing patients with chronic hepatitis B (CHB) is to improve long-term outcomes by decreasing deaths and liver transplantation procedures due to hepatitis B virus (HBV)-related cirrhosis and hepatocellular carcinoma. Active intervention and vaccination of individuals susceptible to HBV infection are key steps to decrease the risk of this global public health problem. Large studies have demonstrated that long-term outcomes of CHB are tied to serum levels of HBV DNA. New oral treatments, characterized by potent antiviral effects, good tolerability, improved histology, stable seroconversion, and minimal resistance, are available. Long-term data with oral medications have shown decreased rates of liver cancer development, liver disease reversal, and progression to liver failure. Pegylated interferon trials have demonstrated modest rates of hepatitis B e antigen seroconversion and improved histology after treatment. This paper describes ways to improve outcomes of CHB using vaccines, interferon, lamivudine, adefovir, and newer agents.

Topics: Adenine; Antiviral Agents; Drug Resistance, Viral; Guanine; Hepatitis B Vaccines; Hepatitis B, Chronic; Humans; Interferon alpha-2; Interferon-alpha; Lamivudine; Nucleosides; Organophosphonates; Polyethylene Glycols; Pyrimidinones; Recombinant Proteins; Telbivudine; Thymidine; Treatment Outcome; Viral Load

The primary goal of treatment in hepatitis B e antigen (HBeAg)-negative patients with chronic hepatitis B (CHB) is potent and durable suppression of hepatitis B virus (HBV) replication. It results in biochemical and histological remission of CHB and is the prerequisite for the prevention of cirrhosis, its life-threatening complications and hepatocellular carcinoma. Responses that are durable after the cessation of treatment are referred to as sustained virological responses, whereas those persisting under therapy are referred to as treatment-maintained virological responses. Treatment paradigms of sustained virological response in HBeAg-negative CHB are practically restricted to conventional IFN-alpha and pegylated interferons (peg-IFNs), and are limited only to patients with compensated liver disease. Long-lasting maintained virological responses without HBV resistance in HBeAg-negative CHB are achievable by all approved nucleos(t)ide analogues (lamivudine, adefovir and entecavir) in highly variable rates, depending on their potency, rapidity of virological response and genetic barrier to resistance. The maintenance of response under 5 years of adefovir treatment represents the most effective treatment paradigm for HBeAg-negative CHB, whereas such long-term data with entecavir and tenofovir monotherapy may become available in the near future. In patients with lamivudine-resistant HBV mutants, the recommended treatment strategy is to add adefovir at the same time as continuing treatment with lamivudine. There are no treatment paradigms as yet of combination therapy from the very outset with two nucleoside analogues for use in treatment-naive patients.

Topics: Adenine; Antiviral Agents; Drug Resistance, Viral; Guanine; Hepatitis B e Antigens; Hepatitis B, Chronic; Humans; Interferon-alpha; Lamivudine; Nucleosides; Organophosphonates; Pyrimidinones; Telbivudine; Thymidine

Topics: Adenine; Antiviral Agents; Guanine; Hepatitis B, Chronic; HIV Infections; Humans; Interferon-alpha; Lamivudine; Nucleosides; Organophosphonates; Pyrimidinones; Telbivudine; Tenofovir; Thymidine

Currently approved treatments for chronic hepatitis B are limited by low rates of sustained response, side effects, or drug resistance. Thus, new treatments that have more potent antiviral effects, less toxicity, and minimal or no risk of resistance are needed. This article will focus on new antiviral agents that are being evaluated in clinical trials.

Topics: Adenine; Animals; Antiviral Agents; Arabinofuranosyluracil; Deoxycytidine; Drug Resistance, Viral; Emtricitabine; Guanine; Hepatitis B virus; Hepatitis B, Chronic; Humans; Lamivudine; Nucleosides; Organophosphonates; Organophosphorus Compounds; Pyrimidinones; Telbivudine; Tenofovir; Thymidine; Treatment Outcome

To investigate the efficacy of Telbivudine and Entecavir for therapy of HBeAg positive chronic hepatitis B for 52 weeks.. In this random and control study, the efficacy of Telbivudine and Entecavir treatments were compared in 180 patients with HBeAg positive chronic hepatitis B.The patients were randomly assigned to a daily 600 mg Telbivudine treatment group or daily 0.5 mg Entecavir group for 52 weeks.. At week 52, HBV DNA undetectable rate was better in the Entecavir-treated group than in the Telbivudine-treated group, but didn't reach statistical significance. The viral breakthrough rates were significantly lower in the Entecavir-treated group than in the Telbivudine-treated group (x2 = 4.09, P <0.05). The clearance and seroconversion of HBeAg and the mean reductions of HBeAg from baseline at week 52 were significantly greater in the telbivudine-treated group than in the entecavir-treated group (x(2) clearance = 4.63, x(2) seroconversion = 4.80, (t-mean) reductions = 2.02; P < 0.05). The HBeAg seroconversion rates were not associated with both baseline ALT and baseline HBV DNA in both groups (P more than 0.05). In Telbivudine-treated group, the HBeAg decline is more than 2 log at week 24, HBeAg decline is more than 1 log at week 12 and the HBeAg baseline were independent factors correlated to HBeAg seroconversion rates at week 52 by Binary Logistic analysis, and also in entecavir-treated group the HBeAg decline is more than 2 log at week 24, HBeAg decline is more than 2 log at week 36 and the HBeAg decline is more than 2 log at week 12 were independent factors correlated to HBeAg seroconversion rates at week 52.. Significant difference of HBeAg seroconversion rates at week 52 existed between Telbivudine-treated group and Entecavir-treated group. Entecavir is significantly superior to Telbivudine with less resistance to nucleosides. HBeAg decline is more than 2 log at week 24 is the best predicting factor for HBeAg seroconversion at week 52.

Topics: Adolescent; Adult; Antiviral Agents; DNA, Viral; Female; Guanine; Hepatitis B e Antigens; Hepatitis B, Chronic; Humans; Male; Middle Aged; Nucleosides; Pyrimidinones; Telbivudine; Thymidine; Treatment Outcome; Young Adult

We characterized the early viral kinetic profiles of telbivudine and entecavir and the effects of these potent nucleoside analogs on hepatitis B virus (HBV) DNA and alanine aminotransferase levels in adults with hepatitis B e antigen-positive compensated chronic hepatitis B. Forty-four patients were enrolled in this open-label, parallel-group, multicenter study and randomized to receive telbivudine or entecavir for 12 weeks. Reductions in hepatitis B virus DNA and alanine aminotransferase levels from baseline to weeks 2, 4, 8, and 12 were assessed. Viral kinetic parameters, including viral clearance per day, loss of infected cells per day, and efficiency of inhibition of viral production, were estimated by using a biphasic mathematical model. Statistical analyses were limited to descriptive analyses. The 2 treatment groups achieved similar reductions in HBV DNA and alanine aminotransferase levels. Mean reductions in levels of hepatitis B virus DNA at week 12 were 6.6 +/- 1.6 and 6.5 +/- 1.5 log(10) copies/ml for the telbivudine- and entecavir-treated patients, respectively. There were no significant differences between groups in values for mean viral clearance per day, mean loss of infected cells per day, or efficiency of blocking viral production. The safety profiles for both medications were favorable. During the first 12 weeks of treatment, telbivudine and entecavir demonstrated similar antiviral potencies, resulting in a rapid and profound suppression of serum hepatitis B virus DNA and reduction of alanine aminotransferase levels. No differences in the effects of these 2 agents on early viral kinetics were observed. Both medications were well tolerated.

Topics: Adult; Alanine Transaminase; Antiviral Agents; DNA, Viral; Female; Guanine; Hepatitis B e Antigens; Hepatitis B virus; Hepatitis B, Chronic; Humans; Kinetics; Male; Middle Aged; Nucleosides; Pyrimidinones; Telbivudine; Thymidine; Treatment Outcome

Because drug-resistant strains of hepatitis B virus (HBV) have developed, and because serum HBV-DNA levels may rebound in patients who receive treatment with nucleoside/nucleotide analogues for up to 2 years, there remains a largely unmet clinical need for agents to induce potent virologic suppression in the initial stage of the disease course of HBV infection.. The aim of this work was to compare the early antiviral effectiveness of telbivudine and entecavir in the treatment of patients with hepatitis B e antigen (HBeAg)-positive HBV.. In this parallel-group, open-label trial, adult Chinese patients with previously untreated HBeAg-positive HBV (HBV-DNA concentration: >or=6 log(10) copies/mL; alanine aminotransferase [ALT] level: >or=2 times the upper limit of normal) were randomized to receive telbivudine 600 mg or entecavir 0.5 mg daily for 24 weeks. Blood samples were collected at the baseline and at 12 and 24 weeks after the treatment. The primary end point was the mean reduction from baseline in serum HBV-DNA concentration at week 24. Secondary end points included mean reduction from baseline in serum HBV-DNA concentration at week 12, the absence of serum HBV-DNA, absence of serum HBeAg, HBeAg seroconversion at week 24, the normalization of serum ALT at week 24, and occurrence of adverse events through week 24.. A total of 131 patients were enrolled in the study: 91 men and 40 women, with a mean (SD) age of 32.5 (8.9) years. All patients were ethnic Han Chinese. The baseline demographic characteristics and serum HBV-DNA concentrations in the 2 treatment groups were well matched. Sixty-five patients were randomized to receive telbivudine and 66 to receive entecavir. The mean reductions from baseline in serum HBV-DNA were 4.99 and 4.69 log(10) copies/mL at week 12, respectively, and 6.00 and 5.80 log(10) copies/mL at week 24 (both time points, P = NS between groups). At week 12, HBV-DNA was undetectable in 43.1% (28/65) of the telbivudine group and 34.8% (23/66) of the entecavir group (P = NS); at week 24, it was undetectable in 67.7% (44/65) of the telbivudine group and 57.6% (38/66) of the entecavir group (P = NS). At week 12, HBeAg absence and seroconversion rates were significantly greater in the telbivudine group than the entecavir group (absence: 20.0% [13/65] vs 3.0% [2/66], respectively [P = 0.002]; seroconversion: 13.8% [9/65] vs 3.0% [2/66] [P = 0.030]). However, at week 24, HBeAg absence and seroconversion rates were comparable between the telbivudine and entecavir groups (absence: 36.9% [24/65] vs 28.8% [19/66] [P = NS]; seroconversion: 24.6% [16/65] vs 13.6% [9/66] [P = NS]). In addition, the normalization of ALT levels was observed in 78.5% (51/65) and 74.2% (49/66) of patients treated with telbivudine and entecavir, respectively, at week 24 (P = NS). The adverse events were upper respiratory tract infection (12.3% of telbivudine patients vs 9.1% of entecavir patients), fatigue (6.2% vs 7.6%), diarrhea (1.5% vs 3.0%), and coughing (0% vs 1.5%), most of which were mild to moderate. Elevated creatinine phosphokinase was noted in 8 telbivudine-treated patients (12.3%). There were no statistically significant differences in rates of adverse events between groups except for creatinine phosphokinase.. In this study of ethnic Han Chinese adults with previously untreated HBeAg-positive HBV infection, there were no statistically significant differences in effectiveness or tolerability between telbivudine 600 mg and entecavir 0.5 mg at the end of 24 weeks of treatment. ChiCTR.org identifier: ChiCTR-TRC-00000341.

Topics: Adult; Antiviral Agents; China; DNA, Viral; Female; Guanine; Hepatitis B; Hepatitis B e Antigens; Hepatitis B, Chronic; Humans; Male; Nucleosides; Pyrimidinones; Telbivudine; Thymidine

To investigate the efficacy of nucleosides as a prophylactic agent against reactivation of hepatitis B virus (HBV) in HBsAg-positive patients with non-hepatic tumors after chemotherapy.. Fifty-eight patients with non-hepatic tumors were divided into prevention group and control group. The patients of prevention group received nucleosides as a prophylactic agent before chemotherapy and were compared with the control ones about the clinical manifestation of HBV reactivation. Then, the patients of the control group were divided into three groups according to antiviral drugs, use or not and time of the use. The patients having HBV reactivation but never received nucleosides were included in the group A, the patients receiving nucleosides after having HBV reactivation were divided into the group B, and the patients receiving nucleosides before HBV reactivation were divided into the group C. The progression, prognosis and curative effect among the three groups were compared.. The rate of HBV reactivation, incidence of severe hepatitis, mortality rate of the control group (61.1%, 27.8%, 16.7%) were significantly higher than those of the prevention group (13.6%, 0, 0), and liver dysfunction was more serious than that in the prevention group. In the control group, all the 5 patients of group A died of liver failure. Of the 13 patients in the group B, 4 cases suffered from severe hepatitis and 1 of them died of the disease. Of the 18 patients in the group C, 4 cases suffered from HBV reactivation, but the clinical manifestation was milder than that of the group B.. Nucleosides can be used as a prophylactic measure to prevent HBV reactivation. If chemotherapy had begun, the use of nucleosides may reduce the risk of HBV reactivation. Even if patients had suffered from HBV reactivation, the use of nucleosides may still help the recovery of liver function and improve prognosis.

Topics: Adult; Antineoplastic Agents; Antiviral Agents; Breast Neoplasms; Female; Follow-Up Studies; Guanine; Hepatitis B; Hepatitis B Surface Antigens; Hepatitis B virus; Humans; Lamivudine; Lung Neoplasms; Lymphoma; Male; Middle Aged; Nucleosides; Pyrimidinones; Retrospective Studies; Telbivudine; Thymidine; Virus Activation

To investigate the efficacy of antiviral treatment on patients with acute-on-chronic hepatitis B liver failure with low viral load.. 352 patients with acute-on-chronic hepatitis B liver failure including 175 cases of low HBV viral load and 177 cases of high HBV viral load were enrolled into this study. The patients were divided into the antiviral group which received antiviral therapy (Lamivudine, Entecavir or Telbivudine) plus routine supportive therapy and the control group which received supportive therapy only. The clinical features and the 24-week short-term efficacy of antiviral therapy were assessed.. At week 24,total survival rate in antiviral group was higher than that in control group (P = 0.010). The survival rate of patients with low viral load in the antiviral group was higher than that in the control group (P = 0.001). But there was no significant difference between the antiviral group and the control group with high viral load (P = 0.856). But in the antiviral group, there was no significant difference in survival rate between the patients with high HBV viral load and those with low viral load (P = 0.755).. Antiviral therapy can significantly improve survival rate of patients of acute-on-chronic hepatitis B liver failure with low viral load. Liver failure;

Topics: Adult; Antiviral Agents; End Stage Liver Disease; Female; Guanine; Hepatitis B, Chronic; Humans; Lamivudine; Liver Failure, Acute; Male; Middle Aged; Nucleosides; Pyrimidinones; Telbivudine; Thymidine; Viral Load

To evaluate the efficacy and safety of telbivudine (LDT) versus entecavir treatments in hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) patients.. Eighty HBeAg-positive compensated CHB patients with HBV DNA more than 6 log10 copies/ml and serum ALT 2 x ULN were divided into two groups: a telbivudine treatment group, and a entecavir treatment group. HBV DNA, ALT and HBeAg were surveyed at baseline and at 12 and 24 weeks. The efficacy and safety of the two nucleoside analogues were assessed at 12 and 24 weeks.. Undetectable serum HBV DNA levels of the telbivudine group (50% and 80%) were similar to those of the entecavir B group (50% and 70%) according to the polymerase-chain-reaction assay at week 12 and 24. There were no significant differences in the normalization of alanine aminotransferase levels between the two groups at week 12 and 24 (52.5% vs 60.0%, 77.5% vs 75.0%). The mean reductions in serum HBV DNA from the baseline levels at week 12 and 24 were similar between the two groups [5.27 vs.5.36, 6.49 vs.6.18 log (on a base-10 scale) copies per milliliter]. More patients in the telbivudine group had HBeAg seroconversion at week 12 than those in the entecavir group (20.0% vs 5.0%, P = 0.043); however, there was no significant difference between the two groups at week 24 (27.5% vs 17.5%). No adverse reactions were found in either group.. There was no significant difference in HBV DNA undetectable rates and the ALT normalization rates between the two groups in a short-term therapy (24 weeks), but the telbivudine group had a higher rate in HBeAg seroconversion than that in the entecavir group at week 12.

Topics: Adolescent; Adult; Aged; Antiviral Agents; Female; Guanine; Hepatitis B e Antigens; Hepatitis B, Chronic; Humans; Male; Middle Aged; Nucleosides; Pyrimidinones; Telbivudine; Thymidine; Viral Load; Young Adult

To evaluate the efficacy of telbivudine and entecavir in chronic hepatitis B (CHB) patients over a 1 year period.. Ninety-seven telbivudine-naive and 98 entecavir-naive CHB patients who had been treated for at least 1 year were enrolled. Serial serum hepatitis B virus (HBV) DNA levels were checked at baseline and at weeks 24 and 48 after treatment.. Entecavir and telbivudine groups had similar baseline HBV DNA levels (5.9 ± 1.7 versus 6.0 ± 1.5 log copies/mL, P=0.529). The undetectable rate of HBV DNA after 1 year of treatment was significantly higher in the entecavir group than the telbivudine group (94.9% versus 82.0%, P=0.009). Resistance developed in 6.7% of the telbivudine-naive patients after 1 year compared with none of the entecavir-naive patients (P=0.009). However, there was a significant difference between the telbivudine and entecavir groups in hepatitis B e antigen (HBeAg) seroconversion 24 weeks after treatment (40% versus 12.5%, P=0.007). Multiple logistic regression analysis revealed that baseline alanine aminotransferase (ALT) >200 IU/L (P=0.008) was independently associated with HBeAg seroconversion. Applying the roadmap concept with ALT >2× upper limit of normal at baseline, telbivudine and entecavir had favourable outcomes in PCR negativity, ALT normalization, HBeAg seroconversion and resistance.. In real-world clinical practice, telbivudine resulted in higher rates of HBeAg seroconversion and drug resistance at week 48 compared with entecavir. A combination with baseline ALT plus 24 week HBV DNA levels led to the lowest rates of resistance in HBeAg-positive telbivudine-naive patients and had the highest probability of HBeAg seroconversion in both entecavir- and telbivudine-naive patients.

Topics: Adult; Alanine Transaminase; Antiviral Agents; DNA, Viral; Drug Resistance, Viral; Female; Guanine; Hepatitis B e Antigens; Hepatitis B virus; Hepatitis B, Chronic; Humans; Male; Middle Aged; Nucleosides; Pyrimidinones; Telbivudine; Thymidine; Time Factors; Treatment Outcome; Viral Load

Treatment choice for chronic HBV infection is a continuously evolving issue, with a wide range of options. We aimed to evaluate the current practice of HBV therapies in the real world in Southern Italy.. A prospective study enrolling over a six month period (February-July 2010) all consecutive HBsAg positive subjects, never previously treated, referred to 16 liver units in two Southern Italy regions (Calabria and Sicily).. Out of 247 subjects evaluated, 116 (46.9%) had HBV-DNA undetectable or lower than 2000 UI/ml. There were 108 (43.7%) inactive carriers, 103 (41.7%) chronic hepatitis, and 36 (14.6%) liver cirrhosis. Antiviral treatment was planned in 94 (38.0%) patients (26 cases with Interferon or Pegylated Interferon and 68 with nucleos(t)ides analogues). As many as 49.5% of subjects with chronic hepatitis did not receive antiviral treatment.. The majority of chronic HBsAg carrier referring centres for evaluation were not considered suitable for antiviral treatment. Nucleos(t)ides analogues are the preferred first choice for therapy. A long-lasting period of observation may be needed to make appropriate therapeutic decisions in several cases.

Topics: Adenine; Adult; Age Factors; Aged; Aged, 80 and over; Antiviral Agents; Female; Guanine; Hepatitis B e Antigens; Hepatitis B, Chronic; Humans; Interferon-alpha; Italy; Lamivudine; Male; Middle Aged; Nucleosides; Organophosphonates; Polyethylene Glycols; Practice Patterns, Physicians'; Pyrimidinones; Recombinant Proteins; Telbivudine; Tenofovir; Thymidine; Young Adult

Current agents used in the treatment of chronic hepatitis B (CHB) can be classified into interferons-α (IFN-α: standard or pegylated) and nucleos(t)ide analogues (NUCs). NUCs are now used in most CHB patients for several reasons. They can be given to all CHB patients, even those with contraindications to IFN-α. NUCs are more convenient to use (one oral tablet daily) than IFN-α (subcutaneous injections) and are well tolerated with a good safety profile, while IFN-α has frequent and potentially severe side effects and worsens the patient's quality of life. All NUCs are potent anti-hepatitis B virus agents (all but adefovir are more potent than IFN-α) with entecavir(ETV) and tenofovir offering the highest potency and most importantly minimal to negligible risk of resistance during long-term monotherapy [corrected]. Prolongation of entecavir or tenofovir monotherapy maintains and slightly increases the initially high virological remission rates (67-76% of HBeAg-positive and 90-93% of HBeAg-negative patients) and this is expected to result in improved long-term outcomes. The need for long-term, perhaps indefinite, treatment is the main limitation of NUCs and the finite duration (48 weeks) the main advantage of IFN-α. However, only a minority of IFN-α-treated patients achieve durable sustained off-treatment responses (HBeAg-positive: 30-35%, HBeAg-negative: 20-25%), while NUCs may be safely discontinued in HBeAg-positive patients with stable HBeAg seroconversion. Because there will always be concerns for safety and family planning issues with long-term therapy, NUCs should be used judiciously and should not be prescribed in young CHB patients with mild liver disease.

Topics: Adenine; Antiviral Agents; Guanine; Hepatitis B e Antigens; Hepatitis B virus; Hepatitis B, Chronic; Humans; Lamivudine; Nucleosides; Organophosphonates; Pyrimidinones; Telbivudine; Tenofovir; Thymidine; Time Factors; Treatment Outcome

The study investigated the hepatitis B virus (HBV) genotypic resistance profile in 1803 nucleos(t)ide analogue (NA)-experienced Chinese patients with chronic HBV infection. Serum HBV DNA was extracted, and the reverse transcriptase region was analysed by a high-sensitive direct PCR sequencing and verified by clonal sequencing if necessary. Drug-resistant mutations were detected in 560 of the 1803 patients, including 214 of 490 patients who received lamivudine (LAM), 35 of 428 patients who received adefovir (ADV), five of 18 patients who received telbivudine and 306 of 794 patients who received various sequential/combined NA therapies. ADV-resistant mutations were detected in 36 of 381 patients who received LAM and then switched-to ADV in contrast to one of 82 patients who received ADV add-on LAM. Entecavir (ETV)-resistant mutations were detected not only in LAM- and ETV-treated patients but also in LAM-treated ETV-naïve patients. Double mutations rtM204I and rtL180M were detected more frequently in genotype C than in genotype B virus, and patients infected with this mutant had higher alanine transaminase levels than those infected with mutant containing the rtM204I substitution alone. Multidrug-resistant HBV strains were identified in eight patients, including two novel strains with mutational patterns rtL180M + A181V + S202G + M204V + N236T and rtL180M + S202G + M204V + N236T. The results provide new information on HBV genotypic resistance profiles in a large cohort of Chinese patients with chronic HBV infection and may have important clinical implication for HBV drug resistance management in China.

Topics: Adenine; Adult; Amino Acid Substitution; Antiviral Agents; China; DNA, Viral; Drug Resistance, Viral; Female; Guanine; Hepatitis B virus; Hepatitis B, Chronic; Humans; Male; Middle Aged; Molecular Sequence Data; Mutation, Missense; Nucleosides; Organophosphonates; Pyrimidinones; RNA-Directed DNA Polymerase; Sequence Analysis, DNA; Telbivudine; Thymidine; Viral Proteins

Serum alanine aminotransferase (ALT) increase is a well-known phenomenon during interferon treatment for chronic hepatitis B. However, little is known about these increases during nucleoside/nucleotide treatment and the effects on long-term clinical outcomes.. A total of 170 treatment-naive hepatitis B e antigen (HBeAg)-positive chronic hepatitis B patients were treated with a nucleoside/nucleotide analogue for at least 2 years and followed up for 1 more year post-treatment. Clinical characteristics were detected and analysed at baseline and at every 3-month interval.. Two patterns of ALT increase, virus- and host-induced, were detected. Virus-induced increases were characterized by a rapid increase in serum ALT and HBV DNA typically after 2 years of treatment, and were more common than host-induced ALT increases (15.9% versus 6.5%; P<0.05) with a median ALT increase of 5.7-fold the upper limit of normal (ULN). Host-induced ALT increases were characterized by moderately increased ALT (median 2.5-fold ULN) with a slow decrease in HBV DNA that occurred mainly in the first year of treatment (63.6%). Most importantly, host-induced increases were associated with favourable long-term treatment outcomes in HBV DNA undetectable rate (82% versus 0%), HBeAg seroconversion (82% versus 7%) and histological improvement. Moreover, interferon-γ-expressing T-helper cells were increased in patients with host-induced ALT increases.. Two patterns of ALT increases may occur during nucleoside/nucleotide analogue treatment. Host induced ALT increases, accompanied by decreased HBV DNA, lead to better long-term clinical outcomes.

Topics: Adenine; Adult; Aged; Alanine Transaminase; Antiviral Agents; DNA, Viral; Female; Guanine; Hepacivirus; Hepatitis B e Antigens; Hepatitis B, Chronic; Humans; Interferon-gamma; Lamivudine; Male; Middle Aged; Nucleosides; Organophosphonates; Predictive Value of Tests; Pyrimidinones; T-Lymphocytes; Telbivudine; Thymidine; Treatment Outcome; Up-Regulation; Young Adult

Most approved drugs with activity against hepatitis B virus (HBV) have activity against human immunodeficiency virus type 1 (HIV-1), which precludes their use in patients who are coinfected with HBV and HIV-1 and who are not receiving antiretroviral therapy due to the risk of inducing resistance. The activity of telbivudine, a highly selective HBV inhibitor, against temporally and geographically distinct wild-type and multidrug-resistant HIV-1 clinical isolates was evaluated in vitro. No inhibition was observed with up to 600 muM drug, which supports further exploration of telbivudine as a therapeutic option for the treatment of HBV infections in patients coinfected with HIV-1.

Topics: Anti-HIV Agents; Antiviral Agents; Drug Resistance, Viral; Guanine; Hepatitis B virus; Hepatitis B, Chronic; HIV Infections; HIV-1; Humans; In Vitro Techniques; Microbial Sensitivity Tests; Nucleosides; Pyrimidinones; Telbivudine; Thymidine

Hepatitis B is a DNA virus affecting hundreds of millions of individuals worldwide. As the clinical sequelae of cirrhosis and hepatocellular cancer are increasingly recognized to be related to viral levels, the impetus increases to offer treatment to those previously not treated. With the development of more robust antivirals with reasonable safety profiles, long-term treatment is becoming more common. The oral nucleos(t)ide analogs have become the preferred first-line therapies for most genotypes of hepatitis B. Five are now available, all with different potencies and resistance profiles. Long-term data spanning several years are now available for most compounds in this arena. This article focuses on the common natural variants and those secondary to nucleos(t)ide therapy, as well as diagnostic methods to detect resistance.

Topics: Adenine; Antiviral Agents; Drug Resistance, Viral; Genetic Testing; Genotype; Guanine; Hepatitis B; Humans; Lamivudine; Nucleosides; Organophosphonates; Phenotype; Pyrimidinones; Telbivudine; Tenofovir; Thymidine

To reduce the incidence of drug resistance and to maintain viral suppression, patients chronically infected with HBV might require combination therapy using two or more drugs with different resistance profiles. We investigated the activity of clevudine (CLV) in combination with other nucleoside/nucleotide analogues to determine if these combinations were compatible in vitro.. Using the HepAD38 cell line, which expresses wild-type HBV, and a real-time PCR assay, we tested the anti-HBV activity of CLV in combination with entecavir, lamivudine, adefovir, tenofovir and telbivudine (TBV). We evaluated the uptake and phosphorylation of CLV in the presence of TBV, using HepAD38 cells and primary hepatocytes to determine the effect of TBV on the phosphorylation of CLV and vice versa. Phosphorylation of TBV and CLV to their corresponding monophosphate by deoxycytidine kinase, thymidine kinase-1 and thymidine kinase-2, and the phosphorylation of TBV monophosphate and CLV monophosphate by thymidylate kinase was evaluated and compared.. When CLV was combined with entecavir, lamivudine, adefovir or tenofovir, a synergistic antiviral effect was observed; however, the combination of CLV and TBV gave an antagonistic antiviral response. The results of in vitro metabolism and enzyme studies suggest that the antagonism observed with the CLV/TBV combination involves competition for uptake and phosphorylation.. The results of our studies demonstrate that combination treatments can provide enhanced antiviral activity and, when used in conjunction with appropriate metabolic investigations, provide a rational basis for the design and development of combination regimens for treating chronic HBV infection.

Topics: Adenine; Anti-HIV Agents; Antiviral Agents; Arabinofuranosyluracil; Cell Line; Cells, Cultured; Drug Antagonism; Drug Synergism; Drug Therapy, Combination; Guanine; Hepatitis B virus; Hepatocytes; Humans; Lamivudine; Microbial Sensitivity Tests; Nucleosides; Nucleotides; Organophosphonates; Pyrimidinones; Reverse Transcriptase Inhibitors; Telbivudine; Tenofovir; Thymidine

The aim of this study was to investigate the economic consequences of nucleoside analog therapy for hepatitis B treatment in China.. A cost-utility analysis of treatments for HBeAg-positive and HBeAg-negative chronic hepatitis B (CHB) was conducted using a Markov model, in which patients' yearly transitions between different health states were tracked. Patients were tracked as they moved between the following health states: CHB, HBeAg seroconversion (HBeAg-positive CHB patients can have this special health state), virologic resistance, virologic response, compensated cirrhosis, decompensated cirrhosis, hepatocellular carcinoma, liver transplantation, and death. The transition parameters were derived either from systematic reviews of the literature or from previous economic studies. Cost and utility data came from studies based on a Chinese CHB cohort. One-way sensitivity analyses as well as second-order Monte Carlo and probabilistic sensitivity analyses were performed.. The entecavir strategy yielded the most quality-adjusted life years (QALYs) for both HBeAg-positive and HBeAg-negative patients when compared with the "no treatment," the lamivudine, the adefovir, and the telbivudine strategies. The risks of complications and mortality also decreased. In the economic analysis, the "no treatment" strategy was the least effective, whereas the entecavir strategy was both the least expensive and the most cost-effective option, followed by telbivudine and lamivudine. The probabilistic sensitivity analysis showed that the entecavir strategy would result in improved cost-effectiveness in >90% of cases at a threshold of $20,000 per QALY. In a one-way sensitivity analysis, the most influential parameters impacting the model's robustness were the utilities of the CHB and virologic response health states.. In China, when treating both HBeAg-positive and HBeAg-negative CHB populations, entecavir is the most cost-effective option when compared with lamivudine, adefovir, and telbivudine.

Topics: Adenine; Antiviral Agents; China; Cost-Benefit Analysis; Guanine; Hepatitis B e Antigens; Hepatitis B, Chronic; Humans; Lamivudine; Markov Chains; Models, Economic; Models, Statistical; Monte Carlo Method; Nucleosides; Organophosphonates; Pyrimidinones; Quality-Adjusted Life Years; Reverse Transcriptase Inhibitors; Serologic Tests; Telbivudine; Thymidine

Hepatitis B virus (HBV) genomic variability is responsible for the complexity of the viral quasi-species and its evolution during the course of infection. The persistence of infected cells promotes the selection of drug-resistant strains. The development of nucleoside analogs without cross-resistance has provided a rationale for combination therapy. De novo combination, with low genetic barrier drugs, prevents the emergence of resistance in the short-term for drugs with a low genetic barrier and improves the control of infection. Long-term studies are needed to determine whether de novo combination is beneficial for analogs with a high genetic barrier as well. The add-on strategy is a standard in case of emergence of resistant mutants. This strategy needs to be implemented as early as possible before the virological breakthrough, especially if the viral suppression is sub-optimal. Clinical trials are mandatory in order to assess whether a) de novo combination is better than an early add-on strategy; and b) whether in case of sub-optimal viral suppression, an early add-on strategy is better in the long-term than a switch to a more potent drug with a high genetic barrier.

Topics: Adenine; Antiviral Agents; Drug Resistance, Viral; Drug Therapy, Combination; Guanine; Hepatitis B, Chronic; Humans; Lamivudine; Nucleosides; Organophosphonates; Pyrimidinones; Telbivudine; Tenofovir; Thymidine

As human immunodeficiency virus (HIV) and hepatitis B virus (HBV) are acquired through the same routes of contamination, the prevalence of HBV serological markers found in the HIV-infected population is approximately 7%. Liver-related mortality and morbidity is higher in HIV/HBV co-infected patients than in HBV mono-infected patients. Both viruses must be considered before a treatment decision is made. According to the European consensus conference on the treatment of chronic hepatitis B and C in HIV coinfected patients, treatment is based on whether there is an existing indication of anti- HIV therapy or not. In patients with no indication of anti-HIV therapy, drugs with dual anti-viral activity (lamivudine, entecavir, tenofovir disoproxil fumarate) should not be used due to the risk of developing HIV-resistance. Interferon or adefovir in combination with telbivudine are recommended. In patients with an indication of anti-HIV therapy, a backbone of highly active anti-retroviral therapy should include tenofovir in combination with lamivudine or emtricitabine. The same regimen is recommended in patients who develop lamivudine resistance.

Topics: Adenine; Antiretroviral Therapy, Highly Active; Antiviral Agents; Deoxycytidine; Drug Resistance, Viral; Drug Therapy, Combination; Emtricitabine; Guanine; Hepatitis B, Chronic; HIV Infections; Humans; Interferon alpha-2; Interferon-alpha; Lamivudine; Nucleosides; Organophosphonates; Pyrimidinones; Recombinant Proteins; Telbivudine; Tenofovir; Thymidine

Antiviral drug-resistant HBV mutants under a variety of treatment protocols are complex and only partly understood. Here, a population-based cross-sectional study was performed to analyse the profile of resistance mutations in distinct evolutionary pathways refractory to different nucleoside/nucleotide analogues (NAs).. Serum samples of 199 chronic hepatitis B patients undergoing NA treatment from five hospitals in four northern cities of China were obtained between January 2007 and July 2009. The genotypic resistance of HBV in these samples was characterized. The full-length HBV reverse transcriptase region was amplified, sequenced and analysed with particular focus on the following NA-resistant changes: rtL80, rtI169, rtV173, rtL180, rtA181, rtT184, rtA194, rtS202, rtM204, rtN236 and rtM250.. Among 199 HBV isolates, 30 (15.08%) and 169 (84.92%) were genotypes B and C, respectively, and 65 (32.66%) harboured NA-resistant mutations. The prevalence of mutations at rtM204 was 34.33% in 134 patients who had received or who had been exposed to lamivudine-based therapy. Five cases of rtN236 mutations were detected exclusively among 75 patients receiving adefovir-dipivoxil-based therapies. A total of 19 cases of multidrug resistance rtA181 mutations were observed in those with lamivudine-, adefovir-dipivoxil- or telbivudine-based treatment (186 cases), but not in those undergoing entecavir treatment (13 cases). Mutations were not found at rtI169, rtT184, rtA194 or rtS202. rtM204 mutations (27 rtM204I, 15 rtM204V and 5 rtM204I/V cases) were detected at the highest frequency among 65 mutants (72.30% [47/65]) and found to display 16 combination mutation patterns, in which rtM204I and rtM204V were significantly associated with rtL80I/V and rtL180M, respectively (P<0.01).. One-third of the studied population harboured NA-resistant HBV with complicated mutation patterns. Monitoring HBV genotypic resistance mutation markers and patterns is therefore shown to be beneficial for optimizing antiviral therapies and for avoiding clinical deterioration.

Topics: Adenine; Adolescent; Adult; Aged; Aged, 80 and over; Antiviral Agents; China; Cross-Sectional Studies; DNA, Viral; Drug Resistance, Viral; Drug Therapy, Combination; Female; Guanine; Hepatitis B virus; Hepatitis B, Chronic; Humans; Lamivudine; Male; Middle Aged; Molecular Typing; Mutation, Missense; Nucleosides; Organophosphonates; Pyrimidinones; Reverse Transcriptase Inhibitors; Telbivudine; Thymidine; Young Adult

Tenofovir is a new effective treatment option for patients with chronic hepatitis B, but could be potentially hampered by mutations in the hepatitis B virus (HBV) polymerase conferring drug resistance. Drug resistance may occur preferentially if long-term administration is required, for example, in patients with hepatitis B e antigen (HBeAg)-negative HBV infection bearing precore (PC) and basal core promoter (BCP) mutations. The rtA194T polymerase mutation has been found in HBV/HIV coinfected patients during tenofovir treatment and may be associated with tenofovir resistance. We generated replication-competent HBV constructs harboring rtA194T alone or in addition to lamivudine (LAM) resistance (rt180M + rtM204V), PC mutations, and BCP mutations and assessed their replicative capacity after transient transfection in human hepatoma cells. The rtA194T polymerase mutation alone or in conjunction with LAM resistance reduced the replication efficiency as compared with wild-type (WT) HBV. In contrast, combination of rtA194T (+/- LAM resistance) with HBeAg-negative PC or BCP mutants increased the replication capacity of the drug-resistant polymerase mutants, thereby restoring the viral replication to similar levels as WT clones. Clones harboring rtA194T showed partial resistance to tenofovir in vitro and also to LAM but remained susceptible to telbivudine and entecavir.. The rtA194T polymerase mutation is associated with partial tenofovir drug resistance and negatively impacts replication competence of HBV constructs. Viral replication, however, can be restored to WT levels, if these polymerase mutations occur together with precore or basic core promoter substitutions as found in HBeAg-negative hepatitis B. Patients with HBeAg-negative chronic HBV infection may therefore be at particular risk when developing drug resistance to tenofovir. Telbivudine or entecavir should be considered as effective alternative treatment options for these patients.

Topics: Adenine; Anti-HIV Agents; Cell Line, Tumor; DNA-Directed DNA Polymerase; Drug Resistance, Viral; Guanine; Hepatitis B; Hepatitis B e Antigens; Hepatitis B virus; Humans; Lamivudine; Mutation; Nucleosides; Organophosphonates; Pyrimidinones; Telbivudine; Tenofovir; Thymidine; Viral Proteins; Virus Replication

Long-term management of some chronic hepatitis B patients might require combination therapy using drugs with distinct resistance profiles to sustain viral suppression and to reduce the resistance-associated failure. Tenofovir disoproxil fumarate (TDF), approved for hepatitis B virus (HBV) and HIV-1 treatment, is active against wildtype HBV and HBV containing YMDD mutations, which confer resistance to emtricitabine (FTC), lamivudine (3TC) and telbivudine (LdT) and contribute to entecavir (ETV) resistance. We therefore evaluated the in vitro anti-HBV activity of tenofovir (TFV), the active parent drug of TDF, combined with FTC, 3TC, ETV, LdT and adefovir (AFV).. The anti-HBV activities of the compounds were tested using the AD38 cell line that expresses wild-type HBV from a tetracycline-controllable promoter. Intracellular HBV DNA levels were quantified using real-time PCR assay and cytotoxicities were assessed with XTT assays. The antiviral data of the drug combinations were evaluated using MacSynergy analyses on the basis of the Bliss independence model as well as isobologram analyses on the basis of the Loewe additivity theory.. All drug combinations tested, FTC+TFV, 3TC+TFV, ETV+TFV, LdT+TFV and AFV+TFV, showed additive antiviral interactions as analysed by MacSynergy. Isobologram analyses revealed that these combination pairs were additive, with the exception of FTC+TFV, which demonstrated slight synergistic activity. No cytotoxic or antagonistic effects were observed with any of the combinations tested.. The combination of TFV with FTC, 3TC, ETV, LdT or AFV had additive to slightly synergistic anti-HBV effects in vitro. These results support the use of TDF as a component in combination regimens with currently available anti-HBV nucleoside analogues.

Topics: Adenine; Antiviral Agents; Cell Line; Cell Survival; Deoxycytidine; Dose-Response Relationship, Drug; Drug Therapy, Combination; Emtricitabine; Guanine; Hepatitis B virus; Hepatitis B, Chronic; Humans; Lamivudine; Nucleosides; Nucleotides; Organophosphonates; Pyrimidinones; Reverse Transcriptase Inhibitors; Telbivudine; Tenofovir; Thymidine

Pretreatment alanine transaminase (ALT) elevation may be used as a predictor for higher hepatitis B e antigen (HBeAg) seroconversion in chronic hepatitis B patients. However, the role of dynamic changes of on-treatment ALT for seroconversion is unknown. A total of 170 naïve HBeAg-positive chronic hepatitis B patients were treated with a nucleoside/nucleotide analogues (NA), either lamivudine, adefovir, entecavir, or telbivudine, for at least 2 years and followed up for 1 more year. Clinical characteristics were detected and analysed at baseline and at 3-month intervals. On-treatment ALT predicted HBeAg seroconversion more accurately than baseline ALT. Among the patients with on-treatment ALT 5 x UNL, HBeAg seroconversion was 11.4, 5.4, 24.4 and 65.0% (odds ratio = 1.0, 0.4, 2.5 and 14.4, respectively), respectively. Moreover, two models/types of seroconversion were observed. Type I was characterized by rapidly decreased ALT and HBV DNA during the first 3-month interval, but with high HBeAg reversion rate (50%) after consolidation treatment. Type II was a slow decreased DNA procedure accompanied by significant elevated ALT with less reversion (23%). Receiver operating characteristic curve analysis showed a 1.9-fold increased ALT ratio (present visit ALT: previous visit ALT) accompanied by at least a 0.8 log decreased HBV DNA may be used to classify these two seroconversion types. We conclude that on-treatment elevated ALT levels is a better predictor for seroconversion after NAs treatment, and HBV DNA profiles may help to identify different models of seroconversion.

Topics: Adenine; Adult; Aged; Alanine Transaminase; Antiviral Agents; DNA, Viral; Female; Follow-Up Studies; Guanine; Hepatitis B e Antigens; Hepatitis B, Chronic; Humans; Lamivudine; Male; Middle Aged; Nucleosides; Organophosphonates; Prognosis; Pyrimidinones; Retrospective Studies; Telbivudine; Thymidine; Young Adult

Chronic hepatitis B affects 5-10% of HIV patients in Western countries. Lamivudine should no longer be used as a single anti-HBV agent in HIV-HBV co-infected patients, given its limited antiviral potency and high risk of selection of resistance, which further results in wide cross-resistance to all other nucleoside analogues. Recent reports of transmission of lamivudine-resistant HBV in HIV patients are of especial concern, and large surveillance studies suggest that it may occur in up to 10% of new HBV infections in Western countries. Another worrisome aspect of the selection of lamivudine-resistant HBV is the potential for selection of vaccine escape mutants. Currently, tenofovir must be viewed as the drug of choice in HIV-HBV co-infected patients in whom antiretroviral therapy is advised. Its co-formulation with emtricitabine (Truvada) is particularly convenient for treating both HIV and HBV in co-infected individuals. While pegIFN-alpha monotherapy for 1 year may be considered for HIV-HBV coinfected individuals with good spontaneous HIV control (elevated CD4 cell count, low plasma HIV-RNA), and certain HBV features (genotype A, HBeAg+, low serum HBV-DNA and elevated ALT), it is clear that very few coinfected patients fulfill these criteria. In HBeAg-negative HIV patients, adefovir may be an option but the relatively low antiviral potency of this drug discourages its wide use. Given its potential anti-HIV activity, both entecavir and telbivudine must only be prescribed with antiretroviral agents. Lack of information about potential pharmacodynamic interactions between entecavir and abacavir (both are guanosine analogues) or between telbivudine and zidovudine or stavudine (all are thymidine analogues) further discourages their concomitant use. At this time, most experts agree that early introduction of anti-HBV active HAART is the best strategy for the treatment of chronic hepatitis B in HIV patients, and Truvada must be part of the triple regimen.

Topics: Adenine; Antiviral Agents; Deoxycytidine; DNA, Viral; Drug Therapy, Combination; Emtricitabine; Guanine; Hepatitis B Surface Antigens; Hepatitis B, Chronic; HIV Infections; Humans; Interferon alpha-2; Interferon-alpha; Lamivudine; Liver Cirrhosis; Nucleosides; Organophosphonates; Polyethylene Glycols; Pyrimidinones; Recombinant Proteins; Telbivudine; Tenofovir; Thymidine; Transaminases

Topics: Adenine; Antiviral Agents; DNA, Viral; Drug Resistance, Viral; Guanine; Hepatitis B e Antigens; Hepatitis B virus; Hepatitis B, Chronic; Humans; Lamivudine; Nucleosides; Organophosphonates; Pyrimidinones; Reverse Transcriptase Inhibitors; Telbivudine; Tenofovir; Thymidine; Treatment Outcome; Virus Replication

Topics: Antiviral Agents; Asia; Drug Therapy, Combination; Guanine; Hepatitis B, Chronic; Humans; Interferon alpha-2; Interferon-alpha; Liver Function Tests; Nucleosides; Pacific Islands; Practice Guidelines as Topic; Pyrimidinones; Recombinant Proteins; Severity of Illness Index; Telbivudine; Thymidine

Topics: Antiviral Agents; Enzyme Inhibitors; Guanine; Hepatitis B Surface Antigens; Hepatitis B virus; Hepatitis B, Chronic; Humans; Nucleosides; Pyrimidinones; Randomized Controlled Trials as Topic; Telbivudine; Thymidine

The new German and American guidelines on hepatitis B show similarities but also some discrepancies. In general, indication for therapy depends more on hepatitis B virus-(HBV-)DNA than alanine aminotransferase (ALT) values. Antivirals are recommended by German guidelines when HBV-DNA exceeds 10,000 copies/ml and ALT is increased more than twice the upper normal limit or when liver biopsy shows significant inflammation and fibrosis. By contrast, American guidelines recommend therapy only when HBV-DNA exceeds 100,000 copies/ml. American guidelines do not recommend lamivudine or telbivudine as initial monotherapy because of risk for resistance, but adefovir or entecavir. By contrast, according to German guidelines monotherapy with lamivudine, telbivudine, adefovir or entecavir may be initiated, if HBV-DNA is < 1 million copies/ml and cirrhosis is absent. Both guidelines recommend to monitor HBV-DNA even in the absence of therapy. Under antiviral therapy HBV-DNA should be measured more often than previously recommended to early identify lack of response and upcoming resistance. When resistance occurs, combination therapy is indicated. Risk for resistance is low as long as viral suppression is effective. In both guidelines liver biopsy should be considered when there are doubts on indication of therapy or selection of antiviral substances. In the presence of severe fibrosis and high HBV-DNA, antiviral substances should have high potency and low risk for resistance.

Topics: Adenine; Alanine Transaminase; Antiviral Agents; Biopsy; DNA, Viral; Drug Resistance, Viral; Drug Therapy, Combination; Germany; Guanine; Hepatitis B; Humans; Lamivudine; Liver; Liver Cirrhosis; Nucleosides; Organophosphonates; Practice Guidelines as Topic; Pyrimidinones; Telbivudine; Thymidine; United States