Nevirapine versus efavirenz in 742 patients: no link of liver toxicity with female sex, and a baseline CD4 cell count greater than 250 cells/microl

Efavirenz or nevirapine in three-drug combination therapy with two nucleoside or nucleotide-reverse transcriptase inhibitors for initial treatment of HIV infection in antiretroviral-naïve individuals

BACKGROUND

The advent of highly active antiretroviral therapy (ART) has reduced the morbidity and mortality due to HIV infection. The World Health Organization (WHO) ART guidelines focus on three classes of antiretroviral drugs, namely nucleoside or nucleotide reverse transcriptase inhibitors (NRTI), non-nucleoside reverse transcriptase inhibitors (NNRTI) and protease inhibitors. Two of the most common medications given as first-line treatment are the NNRTIs, efavirenz (EFV) and nevirapine (NVP). It is unclear which NNRTI is more efficacious for initial therapy. This systematic review was first published in 2010.

OBJECTIVES

To determine which non-nucleoside reverse transcriptase inhibitor, either EFV or NVP, is more effective in suppressing viral load when given in combination with two nucleoside reverse transcriptase inhibitors as part of initial antiretroviral therapy for HIV infection in adults and children.

SEARCH METHODS

We attempted to identify all relevant studies, regardless of language or publication status, in electronic databases and conference proceedings up to 12 August 2016. We searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) and ClinicalTrials.gov to 12 August 2016. We searched LILACS (Latin American and Caribbean Health Sciences Literature) and the Web of Science from 1996 to 12 August 2016. We checked the National Library of Medicine (NLM) Gateway from 1996 to 2009, as it was no longer available after 2009.

SELECTION CRITERIA

We included all randomized controlled trials (RCTs) that compared EFV to NVP in people with HIV without prior exposure to ART, irrespective of the dosage or NRTI's given in combination.The primary outcome of interest was virological success. Other primary outcomes included mortality, clinical progression to AIDS, severe adverse events, and discontinuation of therapy for any reason. Secondary outcomes were change in CD4 count, treatment failure, development of ART drug resistance, and prevention of sexual transmission of HIV.

DATA COLLECTION AND ANALYSIS

Two review authors assessed each reference for inclusion using exclusion criteria that we had established a priori. Two review authors independently extracted data from each included trial using a standardized data extraction form. We analysed data on an intention-to-treat basis. We performed subgroup analyses for concurrent treatment for tuberculosis and dosage of NVP. We followed standard Cochrane methodological procedures.

MAIN RESULTS

Twelve RCTs, which included 3278 participants, met our inclusion criteria. None of these trials included children. The length of follow-up time, study settings, and NRTI combination drugs varied greatly. In five included trials, participants were receiving concurrent treatment for tuberculosis.There was little or no difference between EFV and NVP in virological success (RR 1.04, 95% CI 0.99 to 1.09; 10 trials, 2438 participants; high quality evidence), probably little or no difference in mortality (RR 0.84, 95% CI 0.59 to 1.19; 8 trials, 2317 participants; moderate quality evidence) and progression to AIDS (RR 1.23, 95% CI 0.72 to 2.11; 5 trials, 2005 participants; moderate quality evidence). We are uncertain whether there is a difference in all severe adverse events (RR 0.91, 95% CI 0.71 to 1.18; 8 trials, 2329 participants; very low quality evidence). There is probably little or no difference in discontinuation rate (RR 0.93, 95% CI 0.69 to 1.25; 9 trials, 2384 participants; moderate quality evidence) and change in CD4 count (MD -3.03; 95% CI -17.41 to 11.35; 9 trials, 1829 participants; moderate quality evidence). There may be little or no difference in treatment failure (RR 0.97, 95% CI 0.76 to 1.24; 5 trials, 737 participants; low quality evidence). Development of drug resistance is probably slightly less in the EFV arms (RR 0.76, 95% CI 0.60 to 0.95; 4 trials, 988 participants; moderate quality evidence). No studies were found that looked at sexual transmission of HIV.When we examined the adverse events individually, EFV probably is associated with more people with impaired mental function (7 per 1000) compared to NVP (2 per 1000; RR 4.46, 95% CI 1.65 to 12.03; 6 trials, 2049 participants; moderate quality evidence) but fewer people with elevated transaminases (RR 0.52, 95% CI 0.35 to 0.78; 3 trials, 1299 participants; high quality evidence), fewer people with neutropenia (RR 0.48, 95% CI 0.28 to 0.82; 3 trials, 1799 participants; high quality evidence), and probably fewer people withrash (229 per 100 with NVP versus 133 per 1000 with EFV; RR 0.58, 95% CI 0.34 to 1.00; 7 trials, 2277 participants; moderate quality evidence). We found that there may be little or no difference in gastrointestinal adverse events (RR 0.76, 95% CI 0.48 to 1.21; 6 trials, 2049 participants; low quality evidence), pyrexia (RR 0.65, 95% CI 0.15 to 2.73; 3 trials, 1799 participants; low quality evidence), raised alkaline phosphatase (RR 0.65, 95% CI 0.17 to 2.50; 1 trial, 1007 participants; low quality evidence), raised amylase (RR 1.40, 95% CI 0.72 to 2.73; 2 trials, 1071 participants; low quality evidence) and raised triglycerides (RR 1.10, 95% CI 0.39 to 3.13; 2 trials, 1071 participants; low quality evidence). There was probably little or no difference in serum glutamic oxaloacetic transaminase (SGOT; MD 3.3, 95% CI -2.06 to 8.66; 1 trial, 135 participants; moderate quality evidence), serum glutamic- pyruvic transaminase (SGPT; MD 5.7, 95% CI -4.23 to 15.63; 1 trial, 135 participants; moderate quality evidence) and raised cholesterol (RR 6.03, 95% CI 0.75 to 48.78; 1 trial, 64 participants; moderate quality evidence).Our subgroup analyses revealed that NVP slightly increases mortality when given once daily (RR 0.34, 95% CI 0.13 to 0.90; 3 trials, 678 participants; high quality evidence). There were little or no differences in the primary outcomes for patients who were concurrently receiving treatment for tuberculosis.

AUTHORS' CONCLUSIONS

Both drugs have similar benefits in initial treatment of HIV infection when combined with two NRTIs. The adverse events encountered affect different systems, with EFV more likely to cause central nervous system adverse events and NVP more likely to raise transaminases, cause neutropenia and rash.

Assessment of the nevirapine safety signal using data from the national antiretroviral dispensing database: a retrospective study

BACKGROUND

Clinical trials showed a higher risk of skin- and liver- related adverse reactions when NVP-based antiretroviral therapy (ART) was initiated in female and male patients with baseline CD4 cell counts ≥250 and ≥400, respectively. Some studies reported no difference in risk between the high and low CD4 count groups. Consequently, the use of NVP-based ART in all patients with a CD4 cell count <350, was recommended. In 2011, the Pharmacovigilance Centre detected an increase in reports of grade III and IV reactions. The center was required to determine if there was an increase in NVP-related reactions.

METHODS

Automated dispensing records from January 2008 to November 2011 were accessed from the National Antiretroviral Dispensing Database (NDB). Records of patients who were initiated on NVP-based ART were selected, and records showing a replacement of NVP with protease inhibitor (PI) were identified. The proportions of grade III and IV reactions were calculated per quarter, and Odds Ratios (OR) were calculated, with the confidence interval set at 95 % and a p-value of <0.05.

RESULTS

From 2008 to 2011 a total of 84,741 patients were started on ART. Of these 67,794 were initiated on NVP-containing ART. Of these, 211 females and 79 males were substituted from NVP to a PI. The OR for females was 2.4 (95 % confidence interval [CI] 1.8 - 3.1). For males the OR was 2.4 (OR 2.4; 95 % CI 1.4 - 3.8) which occurred nine months after the change observed in the females. The odds of a NVP-to-PI substitution in females compared to males before the launch of Namibia's 2010 ART guidelines was the same as the odds after the publication of the guidelines (before, OR 1.6; 95 % CI 1.1 - 2.5; after, OR 1.6; 95 % CI 1.2 - 2.2).

CONCLUSIONS

There was an increase in substitutions of NVP with a PI following the increase in the CD4 threshold for initiating NVP-based HAART, meaning that there was an increase in grade III and IV reactions associated with NVP. Therefore the NVP-safety signal was confirmed to be a true signal, which contributed to the Ministry's decision to review the use of NVP.

[Consensus Statement by GeSIDA/National AIDS Plan Secretariat on antiretroviral treatment in adults infected by the human immunodeficiency virus (Updated January 2013)]

OBJECTIVE

This consensus document is an update of combined antiretroviral therapy (cART) guidelines for HIV-1 infected adult patients.

METHODS

To formulate these recommendations a panel composed of members of the GeSIDA/National AIDS Plan Secretariat (Grupo de Estudio de Sida and the Secretaría del Plan Nacional sobre el Sida) reviewed the efficacy and safety advances in clinical trials, cohort and pharmacokinetic studies published in medical journals (PubMed and Embase) or presented in medical scientific meetings. The strength of the recommendations and the evidence which support them are based on a modification of the criteria of Infectious Diseases Society of America.

RESULTS

cART is recommended in patients with symptoms of HIV infection, in pregnant women, in serodiscordant couples with high risk of transmission, in hepatitisB co-infection requiring treatment, and in HIV nephropathy. cART is recommended in asymptomatic patients if CD4 is <500cells/μl. If CD4 are >500cells/μl cART should be considered in the case of chronic hepatitisC, cirrhosis, high cardiovascular risk, plasma viral load >100.000 copies/ml, proportion of CD4 cells <14%, neurocognitive deficits, and in people aged >55years. The objective of cART is to achieve an undetectable viral load. The first cART should include 2 reverse transcriptase inhibitors (RTI) nucleoside analogs and a third drug (a non-analog RTI, a ritonavir boosted protease inhibitor, or an integrase inhibitor). The panel has consensually selected some drug combinations, for the first cART and specific criteria for cART in acute HIV infection, in tuberculosis and other HIV related opportunistic infections, for the women and in pregnancy, in hepatitisB or C co-infection, in HIV-2 infection, and in post-exposure prophylaxis.

CONCLUSIONS

These new guidelines update previous recommendations related to first cART (when to begin and what drugs should be used), how to monitor, and what to do in case of viral failure or adverse drug reactions. cART specific criteria in comorbid patients and special situations are similarly updated.

Adverse events associated with nevirapine and efavirenz-based first-line antiretroviral therapy: a systematic review and meta-analysis

INTRODUCTION

Since 2002, the WHO has recommended either nevirapine (NVP) or efavirenz (EFV) as part of first-line antiretroviral therapy. These two drugs are known to have differing toxicity profiles, but the risk of these toxicities overall is not well established.

METHODS

We systematically reviewed adverse events among treatment-naive HIV-positive adults and children receiving either NVP or EFV as part of first-line antiretroviral therapy. The primary outcome was drug discontinuation as a result of any adverse event; specific toxicities were evaluated as secondary outcomes. Point estimates and 95% confidence intervals (95% CIs) were calculated and proportions and odds ratios (ORs) pooled using fixed-effects meta-analysis.

RESULTS

We reviewed data on 26,446 adults and 3975 children from eight randomized trials and 26 prospective cohorts. Overall, adults on NVP were more than two times more likely to discontinue treatment due to any adverse event compared to patients on EFV (OR 2.2, 95% CI 1.9-2.6). Severe hepatotoxicity (OR 3.3, 95% CI 2.5-4.2), severe skin toxicity (OR 3.9, 95% CI 2.5-5.4), and severe hypersensitivity reactions (OR 2.4, 95% CI 1.9-2.9) were more likely to occur among patients on NVP. Patients receiving EFV were more likely to experience severe central nervous system events (OR 3.4, 95% CI 2.1-5.4). Similar associations were seen in children.

DISCUSSION

Compared to NVP, EFV is associated with a lower frequency of severe adverse events, in particular treatment discontinuations. This finding supports a move toward EFV-based therapy as the preferred first-line treatment regimen for HIV treatment within a public health approach.

Pharmacological and clinical evidence of nevirapine immediate- and extended-release formulations

We reviewed the current information available on nevirapine immediate- and extended-release formulations and its role in single-dose and combination antiretroviral therapy. Nevirapine was approved in 1996 and was the first non-nucleoside reverse-transcriptase inhibitor available for the treatment of HIV-1 infection. Nevirapine has demonstrated good efficacy and a well-characterized safety profile. A major drawback is the low genetic barrier, allowing the emergence of resistance in the presence of single mutations in the reverse-transcriptase gene. This shortcoming is particularly relevant when nevirapine is administered in a single dose to prevent mother-to-child transmission of HIV-1 infection, compromising the efficacy of future non-nucleoside reverse transcriptase-inhibitor regimens. Studies published recently have probed the noninferiority of nevirapine compared to ritonavir-boosted atazanavir with both tenofovir disoproxil fumarate and emtricitabine in antiretroviral treatment-naïve patients. In 2011, a new formulation of nevirapine (nevirapine extended release) that allowed once-daily dosing was approved by the Food and Drug Administration and by the European Medicines Agency. VERxVe, a study comparing nevirapine extended release with nevirapine immediate release in antiretroviral treatment-naïve patients, and TRANxITION, a study carried out in antiretroviral treatment-experienced patients who switched therapy from nevirapine immediate release to nevirapine extended release, provided data on the noninferiority of the new formulation of nevirapine compared with nevirapine immediate release in terms of efficacy and safety. Nevirapine extended release will further increase the durability and persistence of nevirapine-containing antiretroviral therapy, allowing once-daily dosing regimens.

Nevirapine- and efavirenz-associated hepatotoxicity under programmatic conditions in Kenya and Mozambique

To describe the frequency, risk factors, and clinical signs and symptoms associated with hepatotoxicity (HT) in patients on nevirapine- or efavirenz-based antiretroviral therapy (ART), we conducted a retrospective cohort analysis of patients attending the ART clinic in Kibera, Kenya, from April 2003 to December 2006 and in Mavalane, Mozambique, from December 2002 to March 2007. Data were collected on 5832 HIV-positive individuals who had initiated nevirapine- or efavirenz-based ART. Median baseline CD4+ count was 125 cells/μL (interquartile range [IQR] 55–196). Over a median follow-up time of 426 (IQR 147–693) days, 124 (2.4%) patients developed HT. Forty-one (54.7%) of 75 patients with grade 3 HT compared with 21 (80.8%) of 26 with grade 4 had associated clinical signs or symptoms ( P = 0.018). Four (5.7%) of 124 patients with HT died in the first six months compared with 271 (5.3%) of 5159 patients who did not develop HT ( P = 0.315). The proportion of patients developing HT was low and HT was not associated with increased mortality. Clinical signs and symptoms identified 50% of grade 3 HT and most cases of grade 4 HT. This suggests that in settings where alanine aminotransferase measurement is not feasible, nevirapine- and efavirenz-based ART may be given safely without laboratory monitoring.

[Consensus document of Gesida and Spanish Secretariat for the National Plan on AIDS (SPNS) regarding combined antiretroviral treatment in adults infected by the human immunodeficiency virus (January 2012)]

This consensus document has been prepared by a panel consisting of members of the AIDS Study Group (Gesida) and the Spanish Secretariat for the National Plan on AIDS (SPNS) after reviewing the efficacy and safety results of clinical trials, cohort and pharmacokinetic studies published in medical journals, or presented in medical scientific meetings. Gesida has prepared an objective and structured method to prioritise combined antiretroviral treatment (cART) in naïve patients. Recommendations strength (A, B, C) and the evidence which supports them (I, II, III) are based on a modification of the Infectious Diseases Society of America criteria. The current antiretroviral treatment (ART) of choice for chronic HIV infection is the combination of three drugs. ART is recommended in patients with symptomatic HIV infection, in pregnancy, in serodiscordant couples with high transmission risk, hepatitis B fulfilling treatment criteria, and HIV nephropathy. Guidelines on ART treatment in patients with concurrent diagnosis of HIV infection and an opportunistic type C infection are included. In asymptomatic patients ART is recommended on the basis of CD4 lymphocyte counts, plasma viral load and patient co-morbidities, as follows: 1) therapy should be started in patients with CD4 counts <350 cells/μL; 2) when CD4 counts are between 350 and 500 cells/μL, therapy will be recommended and only delayed if patient is reluctant to take it, the CD4 are stabilised, and the plasma viral load is low; 3) therapy could be deferred when CD4 counts are above 500 cells/μL, but should be considered in cases of cirrhosis, chronic hepatitis C, high cardiovascular risk, plasma viral load >10(5) copies/mL, proportion of CD4 cells <14%, and in people aged >55 years. ART should include 2 reverse transcriptase inhibitors nucleoside analogues and a third drug (non-analogue reverse transcriptase inhibitor, ritonavir boosted protease inhibitor or integrase inhibitor). The panel has consensually selected and given priority to using the Gesida score for some drug combinations, some of them co-formulated. The objective of ART is to achieve an undetectable viral load. Adherence to therapy plays an essential role in maintaining antiviral response. Therapeutic options are limited after ART failures, but an undetectable viral load may be possible nowadays. Adverse events are a fading problem of ART. Guidelines in acute HIV infection, in women, in pregnancy, and to prevent mother-to-child transmission and pre- and post-exposition prophylaxis are commented upon. Management of hepatitis B or C co-infection, other co-morbidities, and the characteristics of ART in HIV-2 infection are included.

Pharmacogenetics of toxicity, plasma trough concentration and treatment outcome with nevirapine-containing regimen in anti-retroviral-naïve HIV-infected adults: an exploratory study of the TRIANON ANRS 081 trial

The aim of this exploratory study was to investigate in a homogeneous population of anti-retroviral naïve HIV-1-infected adults, the relationships between genetic polymorphisms involved in nevirapine metabolism [CYP2B6 516G>T, 785A>G and 1459C>T; CYP3A5 6986A>G (CYP3A5*3)], transport (ABCB1 2677G>T/A and 3435C>T), and antigen recognition (HLA-DRB1*0101), and the hepatic and/or cutaneous toxicity occurring within the first 8 or 72 weeks of treatment, plasma trough concentrations (C(trough) ) at week 8 and immuno-virological response to nevirapine at week 24. Associations between genetic polymorphisms and toxicity, C(trough) and response to nevirapine were performed in a population of 72 HIV-1 positive and nevirapine-treated patients followed during 72 weeks, as part of the previous study called: ANRS081 'Trianon' trial. Among the 18 patients who developed toxicity events during the 72 weeks of the study, 12 patients exhibited early toxicity before week 8. No significant association could be evidenced between any of the analysed single nucleotide polymorphisms (SNPs) and nevirapine early or global toxicity, pharmacokinetics and immuno-virological responses even though a possible association between CYP2B6 516G>T and 1459C>T and the trough level of nevirapine was suggested.

Nevirapine-associated toxicity in clinical practice in Buenos Aires, Argentina

OBJECTIVES

to determine the incidence and risk factors for nevirapine (NVP)-associated toxicity in a cohort of HIV-infected people in Buenos Aires, Argentina.

DESIGN

retrospective study.

METHODS

HIV-infected adults who received NVP-based highly active antiretroviral therapy (HAART) at least for 2 weeks between May 1997 and March 2008 were included in this study. We analyzed patients' age, gender, HIV transmission route, HIV disease stage, pregnancy, alcohol intake, adverse events, coinfection with hepatitis B or C virus, time until toxicity, and withdrawal rates.

RESULTS

a total of 1110 patients (631 men) were included. Rash was the most frequently observed adverse event; it was more frequent in women. The incidence of severe rash and hepatotoxicity was similar in women and men. Female sex was the only variable significantly associated with mild-to-moderate rash. High CD4 count, pregnancy, and chronic hepatitis were not associated with NVP-related toxicity. An undetectable viral load at the time of starting NVP treatment resulted in a lower risk of NVP-related rash.

Efavirenz or nevirapine in three-drug combination therapy with two nucleoside-reverse transcriptase inhibitors for initial treatment of HIV infection in antiretroviral-naïve individuals

BACKGROUND

The advent of highly active antiretroviral therapy (HAART) has reduced the morbidity and mortality due to HIV. The World Health Organisation (WHO) antiretroviral treatment (ART) guidelines focus on three classes of antiretroviral drugs, namely: nucleoside/nucleotide reverse transcriptase inhibitors (NRTI), non-nucleoside reverse transcriptase inhibitors (NNRTI) and protease inhibitors (PI). Two of the most common medications given in first-line treatment are the NNRTIs, efavirenz (EFV) and nevirapine (NVP). It is unclear which NNRTI is more efficacious for initial therapy.

OBJECTIVES

To determine which NNRTI, EFV or NVP, is more efficacious when given in combination with two NRTIs as part of initial ART for HIV infection in adults and children.

SEARCH STRATEGY

We used a comprehensive and exhaustive strategy in an attempt to identify all relevant studies, regardless of language or publication status, in electronic databases and conference proceedings from 1996 to 2009.

SELECTION CRITERIA

All randomised controlled trials comparing EFV to NVP in HIV-infected individuals without prior exposure to ART, irrespective of the dosage or NRTI backbone.The primary outcome of interest was virologic response to ART. Other primary outcomes included mortality, clinical progression, severe adverse events, and discontinuation of therapy for any reason. Secondary outcomes were immunologic response to ART, treatment failure, development of ART drug resistance, and prevention of sexual transmission of HIV.

DATA COLLECTION AND ANALYSIS

Two authors assessed each reference for inclusion and exclusion criteria established a priori. Data were abstracted independently using a standardised abstraction form. Data were analysed on an intention-to-treat basis and reported as per dosage of NVP.

MAIN RESULTS

We identified seven randomised controlled trials that met our inclusion criteria.The trials were pooled as per dosage of NVP. None of these trials included children.The seven trials enrolled 1,688 participants and found no critical differences between EFV and NVP, except for different toxicity profiles. EFV is more likely to cause central nervous system side-effects, while NVP is more likely to result in raised transaminases and neutropoenia. There was a higher mortality rate in the NVP 400mg once daily arm.The quality of literature to support these conclusions is moderate to high. Drug resistance was slightly less common with EFV than NVP, but the quality of this literature is low since only one of the seven studies reported on this outcome. No studies reported on sexual transmission of HIV. The length of follow-up time, study settings, and NRTI backbone varied greatly.

AUTHORS' CONCLUSIONS

Both drugs have equivalent efficacies in initial treatment of HIV infection when combined with two NRTIs, but different side effects.

[AIDS Study Group/Spanish AIDS Plan consensus document on antiretroviral therapy in adults with human immunodeficiency virus infection (updated January 2010)]

OBJECTIVE

This consensus document is an update of antiretroviral therapy recommendations for adult patients with human immunodeficiency virus infection.

METHODS

To formulate these recommendations a panel made up of members of the Grupo de Estudio de Sida (Gesida, AIDS Study Group) and the Plan Nacional sobre el Sida (PNS, Spanish AIDS Plan) reviewed the advances in the current understanding of the pathophysiology of human immunodeficiency virus (HIV) infection, the efficacy and safety of clinical trials, and cohort and pharmacokinetic studies published in biomedical journals or presented at scientific meetings. Three levels of evidence were defined according to the data source: randomized studies (level A), cohort or case-control studies (level B), and expert opinion (level C). The decision to recommend, consider or not to recommend ART was established in each situation.

RESULTS

Currently, the treatment of choice for chronic HIV infection is the combination of three drugs of two different classes, including 2 nucleosides or nucleotide analogs (NRTI) plus 1 non-nucleoside (NNRTI) or 1 boosted protease inhibitor (PI/r), but other combinations are possible. Initiation of ART is recommended in patients with symptomatic HIV infection. In asymptomatic patients, initiation of ART is recommended on the basis of CD4 lymphocyte counts, plasma viral load and patient co-morbidities, as follows: 1) therapy should be started in patients with CD4 counts below 350 cells/microl; 2) When CD4 counts are between 350 and 500 cells/microl, therapy should be started in case of cirrhosis, chronic hepatitis C, high cardiovascular risk, HIV nephropathy, HIV viral load above 100,000 copies/ml, proportion of CD4 cells under 14%, and in people aged over 55; 3) Therapy should be deferred when CD4 are above 500 cells/microl, but could be considered if any of previous considerations concurs. Treatment should be initiated in case of hepatitis B requiring treatment and should be considered for reduce sexual transmission. The objective of ART is to achieve an undetectable viral load. Adherence to therapy plays an essential role in maintaining antiviral response. Therapeutic options are limited after ART failures but undetectable viral loads maybe possible with the new drugs even in highly drug experienced patients. Genotype studies are useful in these situations. Drug toxicity of ART therapy is losing importance as benefits exceed adverse effects. Criteria for antiretroviral treatment in acute infection, pregnancy and post-exposure prophylaxis are mentioned as well as the management of HIV co-infection with hepatitis B or C.

CONCLUSIONS

CD4 cells counts, viral load and patient co-morbidities are the most important reference factors to consider when initiating ART in asymptomatic patients. The large number of available drugs, the increased sensitivity of tests to monitor viral load, and the ability to determine viral resistance is leading to a more individualized therapy approach in order to achieve undetectable viral load under any circumstances.

Nevirapine-associated early hepatotoxicity: incidence, risk factors, and associated mortality in a primary care ART programme in South Africa

BACKGROUND

The majority of antiretroviral treatment programmes in sub-Saharan Africa are scaling up antiretroviral treatment using a fixed dose first-line antiretroviral regimen containing stavudine, lamivudine, and nevirapine. One of the primary concerns with the use of this regimen is nevirapine-associated hepatotoxicity.

METHODOLOGY/PRINCIPAL FINDINGS

Study participants were 1809 HIV-infected, antiretroviral naïve adults initiating nevirapine-based antiretroviral therapy between November 2002 and December 2006. The primary outcome was early hepatotoxicity. Secondary outcomes were associations with hepatotoxicity and mortality at six months. The cumulative proportion of early hepatotoxicity ranged from 1.0-2.0% giving an incidence-rate at 102 days of 3.6-7.6 per 100 person-years. Median time to hepatotoxicity was 32 (IQR 28-58) days. At 12 weeks, only 8% of patients had alanine aminotransferase monitoring at all the time-points recommended by national guidelines. No association was found between age, gender, baseline CD4 count, concurrent tuberculosis infection, prior participation in a prevention of mother-to-child-transmission program, or baseline weight and early hepatotoxicity. There was no association between early hepatotoxicity and mortality.

CONCLUSIONS

The cumulative proportion of early hepatotoxicity in nevirapine based antiretroviral therapy was low in this resource-constrained setting. Hepatotoxicity was not associated with mortality. Frequent routine monitoring of alanine aminotransferase proved difficult to implement in this public sector primary care programme. Focused monitoring in the first month may be a more cost-effective and pragmatic option in settings with limited resources. Correlation with clinical signs and symptoms may allow future alanine aminotransferase testing to be dictated by clinical criteria.

[Role of tenofovir in HIV and hepatitis C virus coinfection]

Chronic hepatitis C virus (HCV) infection is common in HIV-infected individuals, especially if the route of infection is intravenous (e.g. intravenous drug use or blood transfusion). Prognosis is poorer in patients with HCV and HIV coinfection than in those with HCV monoinfection, mainly due to the immunodepression caused by HIV infection and probably also to a direct effect of HIV on the liver. Moreover, although antiretroviral therapy can cause liver damage, there is little doubt about the net benefits obtained with triple therapy in coinfected individuals, since suppression of HIV replication and immune recovery help to halt liver damage. However, not all antiretroviral agents are equal and those with the lowest hepatotoxicity and best metabolic profile should be used in coinfected patients, since hepatic steatosis accelerates progression of hepatic fibrosis and insulin resistance hampers the success of treatment with interferon and ribavirin. Tenofovir is currently one of the safest nucleos(t)ide analogues, due to its low hepatotoxicity and its lack of negative interference on treatment of HCV infection.

Should HIV therapy be started at a CD4 cell count above 350 cells/microl in asymptomatic HIV-1-infected patients?

PURPOSE OF REVIEW

The aim is to review the available data that contribute to the debate on the optimal time to initiate highly active antiretroviral therapy (HAART) in HIV-infected individuals with a CD4 cell count more than 350 cells/microl.

RECENT FINDINGS

Although few randomized data exist that can contribute to this debate, a number of findings from observational studies generally support earlier initiation of HAART. In particular, the findings that death rates remain higher in HIV-infected individuals than in uninfected individuals, even when successfully treated, and that both AIDS and several serious non-AIDS events are more common in those with a lower CD4 cell count (even when this count is above 350 cells/microl), suggest that earlier initiation of HAART may prevent much of the excess morbidity and mortality that remains in this patient group.

SUMMARY

Currently, the data would generally support initiation of HAART in patients with CD4 cell counts more than 350 cells/microl. However, given the strong potential for confounding in observational studies and the lack of adjustment for lead-time bias in many analyses, it is not possible to rule out possible long-term detrimental effects of earlier use of HAART until the results from fully powered randomized trials that directly address this issue become available.

Analysis of severe hepatic events associated with nevirapine-containing regimens: CD4+ T-cell count and gender in hepatitis C seropositive and seronegative patients

BACKGROUND

Nevirapine-containing regimens have been associated with a risk of significant elevations of liver transaminase levels. Higher risk in antiretroviral-naive populations has been related to gender and CD4+ T-cell count (women with CD4+ T-cell counts of > or =250/mm(3) or men with CD4+ T-cell counts of > or =400/mm(3), i.e. group at risk). However, recent studies do not confirm this association in HIV populations comprising patients who are antiretroviral-experienced. Moreover, the predictive value of gender and CD4+ T-cell count on the risk of raised transaminase levels has been poorly investigated in populations of patients co-infected with hepatitis C virus (HCV).

METHODS

Analysis of HIV-positive patients receiving nevirapine-containing regimens for the first time was conducted. Grade > or =III hepatotoxicity (i.e. > or =5 x upper limit of normal in alanine aminotranferase or aspartate aminotransferase levels) was the primary endpoint. Univariate and multivariable Cox proportional hazard regression models were separately conducted among HCV-antibody (Ab)-positive and HCV-Ab-negative patients.

RESULTS

Amongst 905 patients, 49% were HCV-Ab-positive and 79% were antiretroviral-experienced. Grade > or =III liver transaminase elevations developed in 7.1% of patients, accounting for an incidence of 2.47 (95% CI 1.97, 3.09) per 100 patient-years of follow-up. HCV-Ab reactivity was associated with a 3-fold increase in risk of developing relevant liver transaminase elevations (95% CI 1.75, 5.3; p < 0.001), whereas gender and CD4+ T-cell count did not impact significantly. When analysis was performed in HCV-Ab-negative patients, the outcome was independently correlated with the group at risk (hazard ratio [HR] 3.66; 95% CI 1.20, 11.14; p = 0.022). By contrast, in HCV-Ab-positive patients, the group at risk was not significantly associated with the outcome.

CONCLUSIONS

Most of the excess rates of relevant raised transaminase levels in patients prescribed nevirapine-containing regimens could be attributed to HCV co-infection. Gender and CD4+ T-cell count appeared to have a statistically significant impact on the risk of relevant transaminase level elevations in HCV-negative, but not in HCV-positive patients, probably due to a diluting effect of HCV. Incidence of hepatic events after nevirapine-containing regimens did not appear to be a major concern in our cohort of patients who were mainly antiretroviral-experienced and negative for HCV-Ab. Preferably, nevirapine should be avoided in HCV co-infected patients and in males with CD4+ T-cell counts of > or =400/mm(3) or females with CD4+ T-cell counts of > or =250/mm(3).

Drug-induced liver disease in 2006

PURPOSE OF REVIEW

To identify the key publications of 2006 dealing with drug-induced liver injury.

RECENT FINDINGS

When given in therapeutic doses over 14 days, acetaminophen produced significant asymptomatic elevations in alanine aminotransferase among healthy volunteers, suggesting that subclinical injury may be more common than previously thought. Acute liver failure in children was shown to differ in several important respects from that seen in adults, notably a much lower incidence of acetaminophen toxicity with nearly half of all cases being indeterminate in origin. The first cases of hepatotoxicity with telithromycin, a new class of ketolide antibiotic, were described along with reports suggesting liver injury from ezetimibe among other agents. The potential for chronic injury to develop after acute drug-induced liver injury was analyzed in a large Swedish database; 5-6% of cases were judged to become chronic, with drugs causing cholestatic injury predominating. Among well described hepatotoxins, new reports appeared with highly active antiretroviral therapy agents, herbal therapies and several antibiotics. Finally, the safe use of pravastatin and pioglitazone was demonstrated in patients with chronic liver disease in controlled clinical trials.

SUMMARY

Drug-induced liver injury remains an important concern for many existing drugs as well as for agents in development.