Risk of selecting K65R in antiretroviral-naive HIV-infected individuals with chronic hepatitis B treated with adefovir

Antiretroviral Effects on HBV/HIV Co-infection and the Natural History of Liver Disease

Hepatitis B virus (HBV) coinfection is common in persons with human immunodeficiency virus (HIV) infection, contributing significantly to morbidity and mortality. Many currently used HIV antiretroviral therapy (ART) regimens provide potent anti-HBV activity and it is recommended that HBV-HIV coinfected persons be treated with ART regimens containing tenofovir. ART has multiple benefits, including increasing rates of HBV clearance after initial infection and potent suppression of HBV DNA in chronic infection. Nevertheless, long-term studies have yet to demonstrate a profound positive impact of ART on HBV-related fibrosis progression and development of endstage liver disease.

Lamivudine plus tenofovir versus lamivudine plus adefovir for the treatment of hepatitis B virus in HIV-coinfected patients, starting antiretroviral therapy

Background

Combination of tenofovir disoproxil fumarate (TDF), lamivudine (3TC) and efavirenz (EFV) is preferred in the treatment of HIV/hepatitis B virus (HBV) coinfection. We postulated that a HBV active nucleoside reverse transcriptase (RT) inhibitor/nucleotide RT inhibitor backbone of adefovir dipivoxil (ADV) +3TC would be as effective as TDF +3TC for the Indian population.

Objective

ADV + 3TC could be an alternative option for these HIV/HBV coinfected individuals, preserving the dually active TDF + 3TC as second-line nucleoside backbone following failure of the first-line ART.

Materials and Methods

This randomised control trial (CTRI/2012/03/002471) was carried out at the ART Centre of Calcutta School of Tropical Medicine, India. Seventy-eight (39 on each arm) treatment-naïve HIV/HBV coinfected patients were randomised to receive either the combination of lamivudine + tenofovir + EFV or lamivudine + adefovir + zidovudine + EFV and followed up for 120 weeks.

Results

Median age of the study participants was 36 years (21-62), majority were male (61/78; 78.2%) and heterosexually (39/78; 50%) infected. Baseline characteristics were identical in both arms. There was no statistically significant difference in median aspartate aminotransferase (37 vs. 29.5 U/L), alanine aminotransferase (ALT) (36 vs. 34.5 U/L), ALT normalisation rate (80 vs. 70%), AST to platelet ratio index (0.45 vs. 0.33), CD4 count (508 vs. 427 cells/mm³), HBV DNA suppression (81.8 vs. 70%), hepatitis B e antigen loss (9 vs. 5%), hepatitis B surface antigen seroclearance rate (6.06 vs. 18.75%) and death (3 vs. 3) at 120 weeks between TDF (n = 33) and ADV (n = 32), respectively.

Conclusions

Adefovir plus lamivudine is an effective alternative of tenofovir plus lamivudine in long-term HBV treatment outcome in HIV/HBV coinfected patients.

Adefovir dipivoxil in chronic hepatitis B: history and current uses

INTRODUCTION

The nucleotide analogue adefovir dipivoxil (ADV) was approved in 2002 for the treatment of chronic infection with hepatitis B virus (HBV), in both hepatitis B e antigen (HBeAg)-positive and -negative patients. ADV 10 mg daily has been associated with improved liver histology, decreased levels of HBV DNA and alanine aminotransferase (ALT), and seroconversion of HBeAg.

AREAS COVERED

This paper reviews the use of ADV as a first-line treatment for chronic hepatitis B and as an add-on therapy in chronic HBV-infected patients with lamivudine resistance. In the years since its launch, clinical resistance to ADV has emerged, and tenofovir and entecavir have shown greater efficacy in reducing viral load.

EXPERT OPINION

Many patients who started antiviral therapy with ADV (either as monotherapy or in combination with lamivudine) remain on this agent because they have undetectable viremia, but its future use will probably diminish because of the availability of more potent drugs. ADV is generally well tolerated, though the 10 mg dose is associated with low risk of nephrotoxicity.

[Human immunodeficiency virus infection and viral hepatitis]

Hepatic complications currently represent one of the leading reasons for medical consultations, hospitalisation, and death in the HIV-infected population. This is due to a large extent to viral hepatitis, given its disproportionate frequency in this population. Chronic hepatitis B affects 5-10% of the HIV-infected population. Vaccination has reduced the incidence of liver disease related to hepatitis-B virus (HBV), and the availability of tenofovir has dramatically improved the prognosis of HIV/HBV carriers. Delta hepatitis affects around 15% of HIV-infected individuals in Europe harbouring positive HBsAg. It has the worst prognosis, given its accelerated course to cirrhosis and the absence of successful therapy. Lastly, chronic hepatitis C is the major cause of liver disease in the HIV population. Although classically linked to persons infected parenterally (i.e., intravenous drug users), outbreaks of acute hepatitis C among homosexual men have been reported over the last decade. Treatment with pegylated interferon plus ribavirin provides a cure in less than 40% of patients. However, the introduction of new direct acting antivirals against hepatitis- C virus (HCV) (telaprevir, boceprevir) has revolutionised the field, as HAART did in 1996 in the HIV field, improving the prognosis of co-infected patients. However, interactions between these drugs and antiretroviral agents and the risk of selective resistance pose huge threats in this population.

Treatment of special populations with chronic hepatitis B infection

All therapeutic agents that are currently in use for the treatment of chronic hepatitis B have been administered to a large number of patients in clinical trials in order to be approved as efficacious and safe. Nevertheless, in these trials, many patients have been excluded either because they have decompensated cirrhosis, or they belong to groups with comorbidities that can seriously affect the underlying liver disease, or where the treatment for chronic hepatitis B virus infection can be contraindicated. Such groups of patients are those with hepatitis D virus, hepatitis C virus and HIV coinfections, patients who have undergone transplantation or are immunosuppressed due to chemotherapy or other treatment, patients with end-stage renal disease under dialysis, acute and fulminant hepatitis B and also, children and pregnant women. In this article, all of the aspects of treatment of these special categories are discussed, since for many of these patients, treatment is of a greater importance compared with the standard patient with chronic hepatitis B, and in real life they represent a great percentage of chronic hepatitis B virus infection patients.

Management and treatment of hepatitis B virus in patients with HIV infection: A practical guide for health care professionals

The management and treatment of HIV and hepatitis B virus (HBV)-coinfected patients present specific challenges for clinicians. The morbidity and mortality related to these concomitant infections are growing concerns, while the use of antiviral drugs effective against both viruses complicates therapeutic decision making. The present document provides guidelines for physicians regarding care and treatment of patients coinfected with HIV and HBV. Primary prevention of HBV in HIV-positive patients is achieved through appropriate vaccination schedules. Follow-up before treatment of HBV may include liver biopsy, screening for hepatocellular carcinoma and testing for esophageal varicies in cases of cirrhosis. In HBV-infected patients requiring treatment, recommendations regarding initiation, duration and choice of first-line drugs are made. Finally, in the case of resistance, appropriate alternative therapies are necessary.

Hepatitis B in HIV: available treatment options and approach to therapy

In the past 5 years, three new drugs were approved for hepatitis B, bringing the total number of therapies to five nucleos(-t)ide analogues and two interferons. Some of these drugs are also active against HIV. As the complexity of hepatitis B treatment increases, it becomes important for practitioners to be familiar with the potency, resistance patterns, and response rates for each hepatitis B agent. In this article, the efficacy in HIV and the best regimens for coinfected patients are discussed for those needing treatment for both infections. A particular emphasis is placed on cross-resistance among hepatitis B drugs.

Frequent hepatitis B virus rebound among HIV-hepatitis B virus-coinfected patients following antiretroviral therapy interruption

BACKGROUND

The impact of antiretroviral therapy (ART) interruption in HIV-hepatitis B virus (HBV)-coinfected patients was examined in the Strategic Management of AntiRetroviral Therapy (SMART) study.

METHODS

Plasma HBV DNA was measured in all hepatitis B surface antigen-positive (HBV-positive) participants at baseline, and at months 1, 2, 4, 6, 8, 10, and 12.

RESULTS

Among HBV-positive participants in the ART interruption (drug conservation) (n = 72) and ART continuation (virological suppression) (n = 62) arms, HBV DNA rebound of more than 1 log from baseline at months 1-4 was seen in 31-33% (P = 0.003) and 3-4% (P = 0.017), respectively. Thirteen HBV-positive participants had HBV DNA rebound of more than 3 log, including 12 in the drug conservation arm, of which eight were on tenofovir-containing regimens. Factors independently associated with a HBV DNA rebound were drug conservation arm (P = 0.0002), nondetectable HBV DNA at baseline (P = 0.007), and black race (P = 0.03). Time to ART reinitiation was shorter (7.5, 15.6, and 17.8 months; P < 0.0001) and proportion reinitiating greater (62.5, 46.5, and 39.7%; P = 0.0002) among HBV-positive participants as compared with hepatitis C virus-positive and non-HBV/hepatitis C virus participants in the drug conservation arm. No hepatic decompensation events occurred among HBV-positive participants in either arm.

CONCLUSION

HBV DNA rebound following ART interruption is common and may be associated with accelerated immune deficiency in HIV-HBV-coinfected patients.

Telbivudine exhibits no inhibitory activity against HIV-1 clinical isolates in vitro

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.

Short communication: transmission of hepatitis B viruses with lamivudine resistance mutations in newly diagnosed HIV individuals

From 1519 newly diagnosed HIV individuals seen in Madrid between the years 2000 and 2008, 65 (4.3%) were HBsAg(+). Two HIV/HBV-coinfected patients showed the lamivudine resistance mutation M204V in HBV while no drug resistance mutations were recognized in HIV. None of them admitted prior exposure to antiretroviral drugs. Thus, HIV/HBV-coinfected patients might benefit from baseline drug resistance testing for both HIV and HBV to optimize the selection of anti-HBV active antiviral therapy.

Viral hepatitis and HIV co-infection

Chronic hepatitis B virus (HBV) infection is overall recognised in 10% of HIV+ persons worldwide, with large differences according to geographical region. Chronic hepatitis C virus (HCV) infection affects 25% of HIV+ individuals, with greater rates ( approximately 75%) in intravenous drug users and persons infected through contaminated blood or blood products. HIV-hepatitis co-infected individuals show an accelerated course of liver disease, with faster progression to cirrhosis. The number of anti-HBV drugs has increased in the last few years, and some agents (e.g. lamivudine, emtricitabine, tenofovir) also exert significant activity against HIV. Emergence of drug resistance challenges the long-term benefit of anti-HBV monotherapy, mainly with lamivudine. The results using new more potent anti-HBV drugs (e.g. tenofovir) are very promising, with prospects for stopping or even revert HBV-related liver damage in most cases. With respect to chronic hepatitis C, the combination of pegylated interferon plus ribavirin given for 1 year permits to achieve sustained HCV clearance in no more than 40% of HIV-HCV co-infected patients. Thus, new direct anti-HCV drugs are eagerly awaited for this population. Although being a minority, HIV+ patients with delta hepatitis and those with multiple hepatitis show the worst prognosis. Appropriate diagnosis and monitoring of chronic viral hepatitis, including the use of non-invasive tools for assessing liver fibrosis and measurement of viral load, may allow to confront adequately chronic viral hepatitis in HIV+ patients, preventing the development of end-stage liver disease, for which the only option available is liver transplantation. This article forms part of a special issue of Antiviral Research marking the 25th anniversary of antiretroviral drug discovery and development, Vol 85, issue 1, 2010.

[Hepatitis B in patients with HIV infection]

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.

Treatment of chronic hepatitis B: recommendations from an Italian workshop

The changing scenario of hepatitis B virus therapy has encouraged the organisation of a workshop, endorsed by three Italian scientific societies, aimed at defining the current recommendations for hepatitis B virus treatment. Liver histology and stage of disease remain fundamental for treatment decisions; interferon and nucleoside/nucleotide analogues-based therapy represent different strategies for different phases of the hepatitis B virus disease. The recommendations defined: new and lower cut-off of hepatitis B virus-DNA for eligibility to therapy according to disease stage, how to optimise the use of nucleoside/nucleotide analogues and to individualise the monitoring of response and what to do with treatment failures. Specific recommendations have also been given for cirrhosis patients, those immune suppressed and co-infected with HIV and other hepatitis viruses.

Care of HIV patients with chronic hepatitis B: updated recommendations from the HIV-Hepatitis B Virus International Panel

Nearly 10% of the estimated 36 million people having HIV worldwide suffer from chronic hepatitis B virus (HBV) infection. The advent of new antiviral agents against HBV and the recent availability of improved molecular diagnostic tools have revolutioned the management of HIV/HBV coinfected patients. The present study represents an update of the current knowledge about HBV/HIV coinfection and an intent to provide practical advise about how to give the best care to HIV-infected persons with chronic hepatitis B.

Comparison of the antiviral activity of adefovir and tenofovir on hepatitis B virus in HIV–HBV-coinfected patients

Background

Characteristics and factors influencing viral decay under tenofovir (TDF) and adefovir (ADV) need to be determined in HIV–HBV-coinfected patients.

Methods

This open-label study compared the HBV dynamics in 85 HIV–HBV-coinfected patients initiating an antiretroviral regimen, either including TDF or associated with ADV. The first 6-month change in viral load was analysed using mixed linear models. The adjusted hazards ratio, comparing the rates of undetectable HBV DNA between treatments, was calculated using a Cox proportional hazard model.

Results

The HBV DNA decay, adjusted for baseline HBV viral load was more pronounced in patients treated with TDF than with ADV at 12 months (66% versus 53%, P=0.0001). Patients in the TDF group presented a steeper slope of decline at 1.1 (95% confidence interval [CI] 0.9–1.3), compared with 0.8 (95% CI 0.6–1.0) in the ADV group ( P=0.036). The mean time to HBV DNA undetectability was 19.3 months (95% CI 16.7–22.0) with TDF and 25.9 months (95% CI 21.1–30.7) with ADV. When adjusted for hepatitis B virus e antigen, HBV DNA and alanine aminotransferase levels at baseline, the influence of treatment on time to HBV DNA undetectability remained in favour of TDF versus ADV (hazard ratio=2.79, 95% CI 1.05–7.40, P=0.039)

Conclusions

TDF influenced more strongly the early-phase HBV DNA kinetics than ADV. This is associated with a sustained antiviral activity in the TDF group, in which patients reached the threshold of HBV undetectability at a faster rate and in a larger proportion than those taking ADV.

The implications of antiviral drugs with activity against hepatitis B virus and HIV

PURPOSE OF REVIEW

Around 10% of individuals infected with HIV suffer from chronic hepatitis B virus infection. This represents at least 4 million people worldwide. HIV infection modifies the course of hepatitis B virus associated liver disease with faster progression to cirrhosis. The number of anti-hepatitis B virus drugs has increased within the last few years, and some of them also exert activity against HIV-1. The aim of this article is to update the current knowledge on antiviral therapy for chronic hepatitis B in HIV-infected patients.

RECENT FINDINGS

In the absence of successful anti-hepatitis B virus therapy, morbidity and mortality associated with liver disease are increased in hepatitis B virus/HIV coinfected individuals. Data derived from studies using new more potent anti-hepatitis B virus drugs are very promising, and strategies to use these antivirals sequentially and/or in combination are being developed. Hopefully, this success will help bring a halt to liver-related complications and death in the hepatitis B virus/HIV coinfected population.

SUMMARY

Appropriate diagnosis and monitoring of chronic hepatitis B, including the use of noninvasive tools for assessing liver fibrosis, measurement of serum hepatitis B virus-DNA, and drug resistance testing, along with wise use of antivirals may convert hepatitis B virus/HIV coinfection into a manageable disease.

Understanding the pathogenesis and management of hepatitis B/HIV and hepatitis B/hepatitis C virus coinfection

The approach to the hepatitis B virus (HBV)-infected patient who is also infected with HIV or hepatitis C virus (HCV) is very different from the approach to the patient with only one virus infection. HBV/HIV coinfection is common. Agents that have dual activity against HBV and HIV should be considered as treatment of choice in combination regimens in HBV/HIV-coinfected patients beginning antiretroviral therapy. In HBV/HCV coinfection HCV usually tends to predominate over HBV. More investigation is needed into the mechanisms by which viral pathogenesis is altered and the optimal treatment modalities for coinfected patients.

The HBV drug entecavir - effects on HIV-1 replication and resistance

Entecavir, a drug approved by the Food and Drug Administration for the treatment of chronic hepatitis B virus (HBV) infection, is not believed to inhibit replication of human immunodeficiency virus type 1 (HIV-1) at clinically relevant doses. We observed that entecavir led to a consistent 1-log(10) decrease in HIV-1 RNA in three persons with HIV-1 and HBV coinfection, and we obtained supportive in vitro evidence that entecavir is a potent partial inhibitor of HIV-1 replication. Detailed analysis showed that in one of these patients, entecavir monotherapy led to an accumulation of HIV-1 variants with the lamivudine-resistant mutation, M184V. In vitro experiments showed that M184V confers resistance to entecavir. Until more is known about HIV-1-resistance patterns and their selection by entecavir, caution is needed with the use of entecavir in persons with HIV-1 and HBV coinfection who are not receiving fully suppressive antiretroviral regimens.

Epidemiology, diagnosis and treatment of chronic hepatitis B in HIV-infected patients (EPIB 2005 STUDY)

OBJECTIVE

To describe the characteristics of hepatitis B (HBV) infection in HIV-infected patients and the impact of anti-HBV treatments.

PATIENTS AND METHODS

All the patients with past or present chronic HBV infection seen in October 2005 in 17 French hospitals were included. Data were retrospectively collected from their first visit in a time-dependent manner, through a detailed standardized questionnaire.

RESULTS

Among 477 HBV-infected patients, 261 (55%) were co-infected with HIV. The HBV-HIV co-infected patients underwent fewer serological, virological and histological evaluations. Initial positive HBe antigenemia (HBe Ag) was more frequent in these patients (57.9 versus 28.6%; P < 10), as was cirrhosis on the initial liver biopsy (17.9 versus 7.6%; P = 0.05). Throughout the mean 5-year follow-up, HBe Ag loss was less frequent (P = 0.04), as was HBe seroconversion (incidence rate 2.6 versus 10/100 patient-years; P < 10). HBe Ag loss was associated with fibrosis improvement (METAVIR score -0.5 +/- 0.4 versus +0.2 +/- 0.6 if persistent positive HBe Ag, P = 0.01). In co-infected patients on tenofovir, adefovir or interferon, HBe seroconversions were seen in patients on combined HBV treatment, the use of which is increasing (58% in 2005). Nevertheless, no significant difference in virological, immunological or biochemical evolution was observed between these different treatments.

CONCLUSIONS

In HBV-HIV co-infected patients, the assessment of HBV infection still needs to be improved, the HBV wild-type remains predominant, and HBe Ag loss is rare and associated with a better histological evolution. There is insufficient evidence of the superiority of combined HBV treatment, and this still needs be demonstrated in long term studies.

The management of HIV and hepatitis B coinfection

PURPOSE OF REVIEW

Coinfection with HIV and hepatitis B virus has a significant impact on the natural history of hepatitis B disease with faster rates of progression to cirrhosis and end stage liver disease. An increasing number of hepatitis B virus active drugs are now available, many of which have dual anti-HIV activity. This review highlights the most important recent developments in the management of HIV and hepatitis B virus coinfection.

RECENT FINDINGS

Natural history studies continue to confirm the increased rate of liver-related mortality in coinfected individuals and the importance of hepatocellular carcinoma in this population. The most recent studies of adefovir and tenofovir in open label use in coinfected individuals are discussed and new data on the activity of emtricitabine, entecavir and pegylated interferon are presented. Strategies for use of these new options for anti-hepatitis B virus therapy in coinfected individuals are discussed.

SUMMARY

Prevention of end stage liver disease and hepatocellular carcinoma in the coinfected population is vital and the increasing availability of drugs with potent anti-hepatitis B activity is encouraging. Appropriate diagnosis and monitoring of hepatitis B, coupled with better understanding of the mechanisms of drug resistance, will enable clinicians to manage coinfection more effectively.

Randomized controlled study of tenofovir and adefovir in chronic hepatitis B virus and HIV infection: ACTG A5127

Chronic hepatitis B virus (HBV) infection is an important cause of morbidity and mortality in subjects coinfected with HIV. Tenofovir disoproxil fumarate (TDF) and adefovir dipivoxil (ADV) are licensed for the treatment of HIV-1 and HBV infection, respectively, but both have in vivo and in vitro activity against HBV. This study evaluated the anti-HBV activity of TDF compared to ADV in HIV/HBV-coinfected subjects. ACTG A5127 was a prospective randomized, double-blind, placebo-controlled trial of daily 10 mg of ADV versus 300 mg of TDF in subjects with HBV and HIV coinfection on stable ART, with serum HBV DNA >/= 100,000 copies/mL, and plasma HIV-1 RNA </= 10,000 copies/mL. This study closed early based on results of a prespecified interim review, as the primary noninferiority end point had been met without safety issues. Fifty-two subjects were randomized. At baseline, 73% of subjects had a plasma HIV-1 RNA < 50 copies/mL, 86% were HBeAg positive, 94% were 3TC resistant, median serum ALT was 52 IU/L, and 98% had compensated liver disease. The mean time-weighted average change in serum HBV DNA from baseline to week 48 (DAVG(48)) was -4.44 log(10) copies/mL for TDF and -3.21 log(10) copies/mL for ADV. There was no difference in toxicity between the 2 treatment arms, with 11 subjects (5 ADV and 6 TDF) experiencing elevations of serum ALT on treatment. In conclusion, over 48 weeks, treatment with either ADV or TDF resulted in clinically important suppression of serum HBV DNA. Both drugs are safe and efficacious for patients coinfected with HBV and HIV.

Antiretroviral therapy in coinfected patients: viral hepatitis and tuberculosis

PURPOSE OF REVIEW

Highly active antiretroviral therapy in coinfected patients is complicated by a potentially increased risk for hepatotoxicity. Therefore, treatment strategies are urgently needed.

RECENT FINDINGS

In HIV/hepatitis B virus coinfected patients with an indication for therapy for both HIV and hepatitis B, tenofovir plus lamivudine or emtricitabine containing highly active antiretroviral therapy regimens are the favored first-line treatment as they include medications which are dually active. Although highly active antiretroviral therapy has no direct effect on hepatitis C replication, the associated immune restoration appears to slow down the progression of liver fibrosis. In patients with HIV and tuberculosis coinfection without any prior highly active antiretroviral therapy, delay of initiation of antiviral therapy for 4-8 weeks after initiation of tuberculosis treatment allows for a better discrimination of causes of adverse events and paradoxical reactions.

SUMMARY

With the introduction of new medications for treatment of hepatitis B virus, therapeutic options for HIV/hepatitis B virus coinfected patients have improved considerably. Initiation of highly active antiretroviral therapy may be a promising option for slowing down further progression of hepatitis C-associated liver disease. Simultaneous treatment of tuberculosis and HIV infection remains a therapeutic challenge requiring specific knowledge of drug-drug interactions as well as management strategies for possible immune reconstitution syndromes.

Management of chronic hepatitis B and C in HIV-coinfected patients

One-third of HIV-infected individuals worldwide suffer from chronic hepatitis C virus (HCV) infection, but chronic hepatitis C affects more than 75% of HIV-positive subjects infected parenterally, such as haemophiliacs and intravenous drug users. Chronic hepatitis B virus (HBV) infection, on the other hand, occurs in 10% of HIV-infected persons, coinfection being more prevalent in Southeast Asia. There are two main reasons for considering HCV and HBV therapy as a priority in HIV-coinfected patients: first, the more rapid liver disease progression seen in this population, leading to end-stage liver disease complications, including hepatocellular carcinoma, at younger ages; and second, the higher risk of developing hepatotoxicity following the initiation of antiretroviral therapy in subjects with underlying chronic hepatitis than in HIV-monoinfected individuals. As highly active antiretroviral therapy (HAART) has dramatically improved the prognosis of those with HIV disease, the consequences of associated illnesses such as hepatitis B and C, which are currently among the leading causes of hospital admission and death in the HIV-infected population, have become more relevant. Therefore, the adequate management of viral hepatitis should now be considered a priority in HIV-coinfected patients. Several guidelines have recently been released in response to this demand. In this article, we discuss the most critical issues highlighted in these documents.