Neuropsychiatric complications of antiretroviral therapy

Brief Report: Insomnia and Risk of Myocardial Infarction Among People With HIV

BACKGROUND

Insomnia is common among people with HIV (PWH) and may be associated with increased risk of myocardial infarction (MI). This study examines the association between insomnia and MI by MI type among PWH.

SETTING

Longitudinal cohort study of PWH at 5 Centers for AIDS Research Network of Integrated Clinical Systems sites.

METHODS

Clinical data and patient-reported measures and outcomes from PWH in care between 2005 and 2018 were used in this study. Insomnia, measured at baseline, was defined as having difficulty falling or staying asleep with bothersome symptoms. The Centers for AIDS Research Network of Integrated Clinical Systems centrally adjudicates MIs using expert reviewers, with distinction between type 1 MI (T1MI) and type 2 MI (T2MI). Associations between insomnia and first incident MI by MI type were measured using separate Cox proportional hazard models adjusted for age, sex, race/ethnicity, traditional cardiovascular disease risk factors (hypertension, dyslipidemia, poor kidney function, diabetes, and smoking), HIV markers (antiretroviral therapy, viral suppression, and CD4 cell count), and stimulant use (cocaine/crack and methamphetamine).

RESULTS

Among 12,448 PWH, 48% reported insomnia. Over a median of 4.4 years of follow-up, 158 T1MIs and 109 T2MIs were identified; approximately half of T2MIs were attributed to sepsis or stimulant use. After adjustment for potential confounders, we found no association between insomnia and T1MI (hazard ratio = 1.05, 95% confidence interval: 0.76 to 1.45) and a 65% increased risk of T2MI among PWH reporting insomnia compared with PWH without insomnia (hazard ratio = 1.65, 95% confidence interval: 1.11 to 2.45).

CONCLUSIONS

PWH reporting insomnia are at an increased risk of T2MI, but not T1MI, compared with PWH without insomnia, highlighting the importance of distinguishing MI types among PWH.

Comparative incidence of adverse drug reaction during the first and subsequent year of antiretroviral therapy in a Nigerian HIV infected Cohort

Background

Despite close to two decades of antiretroviral therapy (ART) in Nigeria, data on late on-onset ART-associated adverse drug reactions (ADRs) are sparse.

Objectives

To describe early and late-onset ADRs and compare their incidence in an outpatient HIV positive Cohort on ART.

Method

We described the incidence of clinical ADRs identified and documented in an outpatient clinic cohort of HIV-positive patients treated between June 2004 and December 2015 at a tertiary health facility in Nigeria. Incidence rates of ADRs during the first and subsequent years of ART were compared.

Results

of the 13,983 patients' data analyzed, 9317 were females (66%), and those in the age bracket of 25 to 45 years made up 78% of the studied population. During 52,411 person-years (py) of ART, 1485 incident ADRs were recorded; Incidence rate (IR) 28.3 (95% confidence interval [CI] 26.9:29.8) ADRs per 1000 person-years (py) of ART. The IR of ADRs was about two times higher in the first year of ART compared to subsequent years of treatment; crude incidence rate ratio (IRR) 1.77 (95% CI 1.59:1.97). Anemia, hypersensitivity reactions, and nervous system disorders had 7, 23, and 5 times higher incidence, respectively, in the first year of therapy, compared to subsequent years.

Conclusion

The first year of ART is the period of highest risk of ADRs. Individual and programmatic treatment success in resource-limited settings requires strategies for early identification and management of ADR during the period of greatest risk of ADRs.

HIV-Associated Apathy/Depression and Neurocognitive Impairments Reflect Persistent Dopamine Deficits

Individuals living with human immunodeficiency virus type 1 (HIV-1) are often plagued by debilitating neurocognitive impairments and affective alterations;the pathophysiology underlying these deficits likely includes dopaminergic system dysfunction. The present review utilized four interrelated aims to critically examine the evidence for dopaminergic alterations following HIV-1 viral protein exposure. First, basal dopamine (DA) values are dependent upon both brain region andexperimental approach (i.e., high-performance liquid chromatography, microdialysis or fast-scan cyclic voltammetry). Second, neurochemical measurements overwhelmingly support decreased DA concentrations following chronic HIV-1 viral protein exposure. Neurocognitive impairments, including alterations in pre-attentive processes and attention, as well as apathetic behaviors, provide an additional line of evidence for dopaminergic deficits in HIV-1. Third, to date, there is no compelling evidence that combination antiretroviral therapy (cART), the primary treatment regimen for HIV-1 seropositive individuals, has any direct pharmacological action on the dopaminergic system. Fourth, the infection of microglia by HIV-1 viral proteins may mechanistically underlie the dopamine deficit observed following chronic HIV-1 viral protein exposure. An inclusive and critical evaluation of the literature, therefore, supports the fundamental conclusion that long-term HIV-1 viral protein exposure leads to a decreased dopaminergic state, which continues to persist despite the advent of cART. Thus, effective treatment of HIV-1-associated apathy/depression and neurocognitive impairments must focus on strategies for rectifying decreases in dopamine function.

Rates and risk factors for suicidal ideation, suicide attempts and suicide deaths in persons with HIV: a systematic review and meta-analysis

BACKGROUND

People living with HIV/AIDS (PLWHA) must contend with a significant burden of disease. However, current studies of this demographic have yielded wide variations in the incidence of suicidality (defined as suicidal ideation, suicide attempt and suicide deaths).

AIMS

This systematic review and meta-analysis aimed to assess the lifetime incidence and prevalence of suicidality in PLWHA.

METHODS

Publications were identified from PubMed (MEDLINE), SCOPUS, OVID (MEDLINE), Joanna Briggs Institute EBP and Cochrane Library databases (from inception to before 1 February 2020). The search strategy included a combination of Medical Subject Headings associated with suicide and HIV. Researchers independently screened records, extracted outcome measures and assessed study quality. Data were pooled using a random-effects model. Subgroup and meta-regression analyses were conducted to explore the associated risk factors and to identify the sources of heterogeneity. Main outcomes were lifetime incidence of suicide completion and lifetime incidence and prevalence of suicidal ideation and suicide attempt.

RESULTS

A total of 185 199 PLWHA were identified from 40 studies (12 cohorts, 27 cross-sectional and 1 nested case-control). The overall incidence of suicide completion in PLWHA was 10.2/1000 persons (95%CI: 4.5 to 23.1), translating to 100-fold higher suicide deaths than the global general population rate of 0.11/1000 persons. The lifetime prevalence of suicide attempts was 158.3/1000 persons (95%CI: 106.9 to 228.2) and of suicidal ideation was 228.3/1000 persons (95%CI: 150.8 to 330.1). Meta-regression revealed that for every 10-percentage point increase in the proportion of people living with HIV with advanced disease (AIDS), the risk of suicide completion increased by 34 per 1000 persons. The quality of evidence by Grading of Recommendations, Assessment, Development and Evaluations for the suicide deaths was graded as 'moderate' quality.

CONCLUSIONS

The risk of suicide death is 100-fold higher in people living with HIV than in the general population. Lifetime incidence of suicidal ideation and attempts are substantially high. Suicide risk assessments should be a priority in PLWHA, especially for those with more advanced disease.

Integration of mental health services into HIV healthcare facilities among Thai adolescents and young adults living with HIV

Introduction

To assess the burden of depression, anxiety and suicidality; and to determine the impact of integrated mental health and HIV services on treatment outcomes among Thai adolescents and young adults living with HIV (AYHIV).

Methods

A multicentre prospective cohort study was conducted among AYHIV (15 to 25 years), and age‐ and sex‐matched HIV‐uninfected adolescents and young adults (HUAY). The Patient Health Questionnaire 9‐item (PHQ‐9) and Generalized Anxiety Disorder 7‐item scales (GAD‐7) were used as screening tools for depressive and anxiety symptoms respectively. History of lifetime and recent suicidal ideations/attempts were ascertained. Elevated mental health screening scores were defined as having either significant depressive symptoms (PHQ‐9 ≥9), significant anxiety symptoms (GAD‐7 ≥10) or suicidality (lifetime; and recent [within two weeks]). Participants meeting these criteria were referred to psychiatrists for confirmatory diagnosis and mental health services. Follow‐up assessment with PHQ‐9 and GAD‐7 was performed one year after psychiatric referral.

Results

From February to April 2018, 150 AYHIV and 150 HUAY were enrolled, median age was 19.0 (IQR:16.8 to 21.8) years and 56% lived in urban areas. Among AYHIV, 73% had HIV RNA <50 copies/mL, and median CD4 count was 580 (IQR:376 to 744) cells/mm³. At enrolment, 31 AYHIV (21%; 95%CI:14% to 28%) had elevated mental health screening scores; 17 (11%) significant depressive symptoms, 11 (7%) significant anxiety symptoms and 21 (14%) suicidality. Seven AYHIV (5%) had all three co‐existing conditions. These prevalences were not substantially different from HUAY. Urban living increased risk, whereas older age decreased risk of elevated mental health screening scores (p < 0.05). All AYHIV with elevated mental health screening scores were referred to study psychiatrists, and 19 (13%; 95%CI: 8% to 19%) had psychiatrist‐confirmed mental health disorders (MHDs), including adjustment disorder (n = 5), major depression (n = 4), anxiety disorders (n = 2), post‐traumatic stress disorder (n = 1) and mixed MHDs (n = 4). One year after psychiatric referral, 42% of AYHIV who received mental health services demonstrated an absence of significant mental health symptoms from the reassessments, and 26% had an improved score.

Conclusions

With the significant burden of MHDs among AYHIV, an integration of mental health services, including mental health screenings, and psychiatric consultation and referral, is critically needed and should be scaled up in HIV healthcare facilities.

Rates and risk factors for suicidal ideation, suicide attempts and suicide deaths in persons with HIV: a protocol for a systematic review and meta-analysis

INTRODUCTION

The prevalence of HIV/AIDS is high and is associated with psychiatric morbidity and suicide risk. The objective of this study will be to assess the rates of suicidal ideation, suicide attempts and suicide deaths in people living with HIV/AIDS (PLWHA).

METHODS AND ANALYSIS

We present a study protocol for a systematic review and meta-analysis of studies reporting the suicidality outcomes (suicidal ideation, suicide attempts and suicide deaths) in PLWHA. PubMed (MEDLINE), Scopus, EMBASE, Cochrane Library, OVID (HEALTH STAR), OVID (MEDLINE), Joanna Briggs Institute EBP Database, Web of Science and PsychINFO databases will be searched from their inception until 1 January 2020. The primary outcome of interest will be the incidence of suicidality in PLWHA. In addition, we will delineate risk factors associated with suicidality in PLWHA. Citations, full-text articles and abstracts will be screened by four reviewers independently. Disagreements will be resolved through discussion. The study methodological quality (or bias) will be appraised using an appropriate tool. Random-effects meta-analysis will be conducted if we find that the studies are very heterogenous. For the suicidality outcome, probability of suicide risk will be reported. Relative risk ratios (with 95% CIs) will be reported for the effects of the risk factors. Potential publication bias will be assessed by conducting Egger's test and creating funnel plots. We will conduct additional analyses to explore the potential sources of heterogeneity (eg, age, sex and geographical location).

ETHICS AND DISSEMINATION

No ethics clearance is required as no primary data will be collected. The results of this systematic review and meta-analysis will be presented at scientific conferences and published in a peer-reviewed journal. The results may inform clinical management of PLWHA and may guide future population-specific interventions.We will search PubMed (MEDLINE), Scopus, EMBASE, Cochrane Library, OVID (HEALTH STAR), OVID (MEDLINE), Joanna Briggs Institute EBP Database, Web of Science and PsychINFO from their inception until 1 January 2020.

PROSPERO REGISTRATION NUMBER

CRD42020161501.

Evaluation of Oral Antiretroviral Drugs in Mice With Metabolic and Neurologic Complications

Antiretroviral (ART) drugs has previously been associated with lipodystrophic syndrome, metabolic consequences, and neuropsychiatric complications. ART drugs include three main classes of protease inhibitors (PIs), nucleoside analog reverse transcriptase inhibitors (NRTIs), and non-nucleoside reverse transcriptase inhibitors (NNRTIs). Our previous work demonstrated that a high risk of hyperlipidemia was observed in HIV-1-infected patients who received ART drugs in Taiwan. Patients receiving ART drugs containing either Abacavir/Lamivudine (Aba/Lam; NRTI/NRTI), Lamivudine/Zidovudine (Lam/Zido; NRTI/NRTI), or Lopinavir/Ritonavir (Lop/Rit; PI) have the highest risk of hyperlipidemia. The aim of this study was to investigate the effects of Aba/Lam (NRTI/NRTI), Lam/Zido (NRTI/NRTI), and Lop/Rit (PI) on metabolic and neurologic functions in mice. Groups of C57BL/6 mice were administered Aba/Lam, Lam/Zido, or Lop/Rit, orally, once daily for a period of 4 weeks. The mice were then extensively tested for metabolic and neurologic parameters. In addition, the effect of Aba/Lam, Lam/Zido, and Lop/Rit on lipid metabolism was assessed in HepG2 hepatocytes and during the 3T3-L1 preadipocyte differentiation. Administration with Aba/Lam caused cognitive and motor impairments in mice, as well as their metabolic imbalances, including alterations in leptin serum levels. Administration with Lop/Rit also caused cognitive and motor impairments in mice, as well as their metabolic imbalances, including alterations in serum levels of total cholesterol, and HDL-c. Treatment of mice with Aba/Lam and Lop/Rit enhanced the lipid accumulation in the liver, and the decrease in AMP-activated protein kinase (AMPK) phosphorylation and/or its downstream target acetyl-CoA carboxylase (ACC) protein expression. In HepG2 hepatocytes, Aba/Lam, Lam/Zido, and Lop/Rit also enhanced the lipid accumulation and decreased phosphorylated AMPK and ACC proteins. In 3T3-L1 pre-adipocyte differentiation, Aba/Lam and Lop/Rit reduced adipogenesis by decreasing expression of transcription factor CEBPb, implicating the lipodystrophic syndrome. Our results demonstrate that daily oral administration of Aba/Lam and Lop/Rit may produce cognitive, motor, and metabolic impairments in mice, regardless of HIV-1 infection.

Efavirenz exposure, alone and in combination with known drugs of abuse, engenders addictive-like bio-behavioural changes in rats

Efavirenz is abused in a cannabis-containing mixture known as Nyaope. The addictive-like effects of efavirenz (5, 10 and 20 mg/kg) was explored using conditioned place preference (CPP) in rats following sub-acute exposure vs. methamphetamine (MA; 1 mg/kg) and Δ⁹-tetrahydrocannabinol (THC; 0.75 mg/kg). The most addictive dose of efavirenz was then compared to THC alone and THC plus efavirenz following sub-chronic exposure using multiple behavioural measures, viz. CPP, sucrose preference test (SPT) and locomotor activity. Peripheral superoxide dismutase (SOD), regional brain lipid peroxidation and monoamines were also determined. Sub-acute efavirenz (5 mg/kg) had a significant rewarding effect in the CPP comparable to MA and THC. Sub-chronic efavirenz (5 mg/kg) and THC + efavirenz were equally rewarding using CPP, with increased cortico-striatal dopamine (DA), and increased lipid peroxidation and SOD. Sub-chronic THC did not produce CPP but significantly increased SOD and decreased hippocampal DA. Sub-chronic THC + efavirenz was hedonic in the SPT and superior to THC alone regarding cortico-striatal lipid peroxidation and sucrose preference. THC + efavirenz increased cortico-striatal DA and decreased serotonin (5-HT). Concluding, efavirenz has dose-dependent rewarding effects, increases oxidative stress and alters regional brain monoamines. Efavirenz is hedonic when combined with THC, highlighting its abuse potential when combined with THC.

Neuropsychiatric manifestations among HIV-1 infected African patients receiving efavirenz-based cART with or without tuberculosis treatment containing rifampicin

Purpose

Efavirenz-based combination antiretroviral therapy (cART) is associated with neuropsychiatric adverse events. We investigated the time to onset, duration, clinical implications, impact of pharmacogenetic variations, and anti-tuberculosis co-treatment on efavirenz-associated neuropsychiatric manifestations.

Methods

Prospective cohort study of cART naïve HIV patients with or without tuberculosis (HIV-TB) co-infection treated with efavirenz-based cART. Rifampicin-based anti-tuberculosis therapy was initiated 4 weeks prior to efavirenz-based cART in HIV-TB patients. Data on demographic, clinical, laboratory, and a 29-item questionnaire on neuropsychiatric manifestations were collected for 16 weeks after cART initiation. Genotyping for CYP2B6, CYP3A5, SLCO1B1, and ABCB1 and quantification of efavirenz plasma concentration were done on the 4th and 16th week.

Results

Data from 458 patients (243 HIV-only and 215 HIV-TB) were analyzed. Overall incidence of neuropsychiatric manifestations was 57.6% being higher in HIV-only (66.7%) compared to HIV-TB patients (47.4%) (p < 0.01). HIV-only patients were more symptomatic, with proportionately higher grades of manifestations compared to HIV-TB patients. Median time to manifestations was 1 week after cART initiation in HIV-only and 6 weeks after anti-TB (i.e., 2 weeks after cART initiation) in HIV-TB patients. HIV-only patients had significantly higher efavirenz plasma concentrations at 4 weeks after cART compared to HIV-TB patients. No association of sex or genotype was seen in relation to neuropsychiatric manifestations. Risk for neuropsychiatric manifestations was three times more in HIV-only patients compared to HIV-TB (p < 0.01).

Conclusions

Incidence of neuropsychiatric manifestations during early initiation of efavirenz-based cART is high in Tanzanian HIV patients. Risk of neuropsychiatric manifestations is lower in HIV patients co-treated with rifampicin containing anti-TB compared to those treated with efavirenz-based cART only.

Electronic supplementary material

The online version of this article (10.1007/s00228-018-2499-0) contains supplementary material, which is available to authorized users.

Antidepressants for depression in adults with HIV infection

BACKGROUND

Rates of major depression among people living with HIV (PLWH) are substantially higher than those seen in the general population and this may adversely affect antiretroviral treatment outcomes. Several unique clinical and psychosocial factors may contribute to the development and persistence of depression in PLWH. Given these influences, it is unclear if antidepressant therapy is as effective for PLWH as the general population.

OBJECTIVES

To assess the efficacy of antidepressant therapy for treatment of depression in PLWH.

SEARCH METHODS

We searched The Cochrane Common Mental Disorders Group's specialised register (CCMD-CTR), the Cochrane Library, PubMed, Embase and ran a cited reference search on the Web of Science for reports of all included studies. We conducted additional searches of the international trial registers including; ClinicalTrials.gov, World Health Organization Trials Portal (ICTRP), and the HIV and AIDS - Clinical trials register. We searched grey literature and reference lists to identify additional studies and contacted authors to obtain missing data. We applied no restrictions on date, language or publication status to the searches, which included studies conducted between 1 January 1980 and 18 April 2017.

SELECTION CRITERIA

We included randomized controlled trials of antidepressant drug therapy compared to placebo or another antidepressant drug class. Participants eligible for inclusion had to be aged 18 years and older, from any setting, and have both HIV and depression. Depression was defined according to Diagnostic and Statistical Manual of Mental Disorders or International Statistical Classification of Diseases criteria.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria and extracted data. We presented categorical outcomes as risk ratios (RR) with 95% confidence intervals (CIs). Continuous outcomes were presented mean (MD) or standardized mean differences (SMD) with standard deviations (SD). We assessed quality of evidence using the GRADE approach.

MAIN RESULTS

We included 10 studies with 709 participants in this review. Of the 10 studies, eight were conducted in high income countries (USA and Italy), seven were conducted prior to 2000 and seven had predominantly men. Seven studies assessed antidepressants versus placebo, two compared different antidepressant classes and one had three arms comparing two antidepressant classes with placebo.Antidepressant therapy may result in a greater improvement in depression compared to placebo. There was a moderate improvement in depression when assessed with the Hamilton Depression Rating Scale (HAM-D) score as a continuous outcome (SMD 0.59, 95% CI 0.21 to 0.96; participants = 357; studies = 6; I² = 62%, low quality evidence). However, there was no evidence of improvement when this was assessed with HAM-D score as a dichotomized outcome (RR 1.10, 95% CI 0.89 to 1.35; participants = 434; studies = 5; I² = 0%, low quality evidence) or Clinical Global Impression of Improvement (CGI-I) score (RR 1.28, 95% CI 0.93 to 1.77; participants = 346; studies = 4; I² = 29%, low quality evidence). There was little to no difference in the proportion of study dropouts between study arms (RR 1.28, 95% CI 0.91 to 1.80; participants = 306; studies = 4; I² = 0%, moderate quality evidence).The methods of reporting adverse events varied substantially between studies, this resulted in very low quality evidence contributing to a pooled estimate (RR 0.88, 95% CI 0.64 to 1.21; participants = 167; studies = 2; I² = 34%; very low quality evidence). Based on this, we were unable to determine if there was a difference in the proportion of participants experiencing adverse events in the antidepressant versus placebo arms. However, sexual dysfunction was reported commonly in people receiving selective serotonin reuptake inhibitors (SSRIs). People receiving tricyclic antidepressants (TCAs) frequently reported anticholinergic adverse effects such as dry mouth and constipation. There were no reported grade 3 or 4 adverse events in any study group.There was no evidence of a difference in follow-up CD4 count at study termination (MD -6.31 cells/mm³, 95% CI -72.76 to 60.14; participants = 176; studies = 3; I² = 0%; low quality evidence). Only one study evaluated quality of life score (MD 3.60, 95% CI -0.38 to 7.58; participants = 87; studies = 1; very low quality evidence), due to the poor quality evidence we could not draw conclusions for this outcome.There were few studies comparing different antidepressant classes. We are uncertain if SSRIs differ from TCAs with regard to improvement in depression as evaluated by HAM-D score (MD -3.20, 95% CI -10.87 to 4.47; participants = 14; studies = 1; very low quality evidence). There was some evidence that mirtazapine resulted in a greater improvement in depression compared to an SSRI (MD 9.00, 95% CI 3.61 to 14.39; participants = 70; studies = 1; low quality evidence); however, this finding was not consistent for all measures of improvement in depression for this comparison.No studies reported on virological suppression or any other HIV specific outcomes.The studies included in this review had an overall unclear or high risk of bias due to under-reporting of study methods, high risk of attrition bias and inadequate sequence generation methods. Heterogeneity between studies and the limited number of participants, and events lead to downgrading of the quality of the evidence for several outcomes.

AUTHORS' CONCLUSIONS

This review demonstrates that antidepressant therapy may be more beneficial than placebo for the treatment of depression in PLWH. The low quality of the evidence contributing to this assessment and the lack of studies representing PLWH from generalized epidemics in low- to middle-income countries make the relevance of these finding in today's context limited. Future studies that evaluate the effectiveness of antidepressant therapy should be designed and conducted rigorously. Such studies should incorporate evaluation of stepped care models and health system strengthening interventions in the study design. In addition, outcomes related to HIV care and antiretroviral therapy should be reported.

Digital Pharmacovigilance and Disease Surveillance: Combining Traditional and Big-Data Systems for Better Public Health

The digital revolution has contributed to very large data sets (ie, big data) relevant for public health. The two major data sources are electronic health records from traditional health systems and patient-generated data. As the two data sources have complementary strengths-high veracity in the data from traditional sources and high velocity and variety in patient-generated data-they can be combined to build more-robust public health systems. However, they also have unique challenges. Patient-generated data in particular are often completely unstructured and highly context dependent, posing essentially a machine-learning challenge. Some recent examples from infectious disease surveillance and adverse drug event monitoring demonstrate that the technical challenges can be solved. Despite these advances, the problem of verification remains, and unless traditional and digital epidemiologic approaches are combined, these data sources will be constrained by their intrinsic limits.

The dual modulatory effects of efavirenz on GABAA receptors are mediated via two distinct sites

Efavirenz is a widely prescribed medicine used to treat type 1 human immunodeficiency virus (HIV-1), the most prevalent pathogenic strain of the virus responsible for the acquired immune deficiency syndrome (AIDS) pandemic. Under prescribed dosing conditions, either alone or in combination therapy, efavirenz-induced CNS disturbances are frequently reported. Efavirenz was recently reported to interact in a similar concentration range with a number of receptors, transporters and ion channels including recombinant rat α1β2γ2 GABA_A receptors whose actions were potentiated (Gatch et al., 2013; Dalwadi et al., 2016). Now we report on the molecular mechanism of efavirenz on GABA_A receptors as a function of concentration and subunit composition via whole-cell recordings of GABA-activated currents from HEK293 cells expressing varying subunit configurations of GABA_A receptors. Efavirenz elicited dual effects on the GABA response; it allosterically potentiated currents at low concentrations, whereas it inhibited currents at higher concentrations. The allosteric potentiating action on GABA_A receptors was pronounced in the α1β2γ2, α2β2γ2 and α4β2γ2 configurations, greatly diminished in the α6β2γ2 configuration, and completely absent in the α3β2γ2 or α5β2γ2 configuration. In stark contrast, the inhibitory modulation of efavirenz at higher concentrations was evident in all subunit configurations examined. Moreover, efavirenz-induced modulatory effects were dependent on GABA concentration ([GABA]), with a pronounced impact on currents activated by low [GABA] but little effect at saturating [GABA]. Mutation of a highly-conserved threonine to phenylalanine in transmembrane domain 2 of the α1 subunit abolished the inhibitory effect of efavirenz in α1β2 receptors. Finally, mutations of any of the three conserved extracellular residues in α1/2/4 subunits to the conserved residues at the corresponding positions in α3/5 subunits (i.e., R84P, M89L or I120L) completely eliminated the potentiating effect of efavirenz in α1β2γ2 configuration. These findings demonstrate that efavirenz's positive allosteric modulation of the GABA_A receptor is mediated via a novel allosteric site associated with the extracellular domain of the receptor.

Tryptophan Metabolism and Its Relationship with Depression and Cognitive Impairment Among HIV-infected Individuals

OBJECTIVE

Cognitive impairment (CI) and major depressive disorder (MDD) remain prevalent in treated HIV-1 disease; however, the pathogenesis remains elusive. A possible contributing mechanism is immune-mediated degradation of tryptophan (TRP) via the kynurenine (KYN) pathway, resulting in decreased production of serotonin and accumulation of TRP degradation products. We explored the association of these biochemical pathways and their relationship with CI and MDD in HIV-positive (HIV+) individuals.

METHODS

In a cross-sectional analysis, concentrations of neopterin (NEO), tumor necrosis factor-alpha, TRP, KYN, KYN/TRP ratio, phenylalanine (PHE), tyrosine (TYR), PHE/TYR ratio, and nitrite were assessed in the cerebrospinal fluid (CSF) and plasma of HIV+ (n = 91) and HIV-negative (HIV−) individuals (n = 66). CI and MDD were assessed via a comprehensive neuropsychological test battery. A Global Deficit Score ≥0.5 was defined as CI. Nonparametric statistical analyses included Kruskal–Wallis and Mann–Whitney U tests, and multivariate logistic regression.

RESULTS

Following Bonferroni correction, NEO concentrations were found to be greater in CSF and TRP concentration was found to be lower in the plasma of HIV+ versus HIV− individuals, including a subgroup of aviremic (defined as HIV-1 RNA <50 cps/mL) HIV+ participants receiving antiretroviral therapy (n = 44). There was a nonsignificant trend toward higher KYN/TRP ratios in plasma in the HIV+ group (P = 0.027; Bonferroni corrected α = 0.0027). In a logistic regression model, lower KYN/TRP ratios in plasma were associated with CI and MDD in the overall HIV+ group (P = 0.038 and P = 0.063, respectively) and the aviremic subgroup (P = 0.066 and P = 0.027, respectively), though this observation was not statistically significant following Bonferroni correction (Bonferroni corrected α = 0.0031).

CONCLUSIONS

We observed a trend toward lower KYN/TRP ratios in aviremic HIV+ patients with CI and MDD.

Neurotoxicity in the Post-HAART Era: Caution for the Antiretroviral Therapeutics

Despite the advent of highly active antiretroviral therapy (HAART), HIV-associated neurological disorders (HAND) remain a major challenge in human immunodeficiency virus (HIV) treatment. The early implementation of HAART in the infected individuals helps suppress the viral replication in the plasma and other compartments. Several studies also report the beneficial effect of drugs that successfully penetrate central nervous system (CNS). However, recent data in both clinical setup and in in vitro studies indicate CNS toxicity of the antiretrovirals (ARVs). Although the evidence is limited, correlation between prolonged use of ARVs and neurotoxicity strongly suggests that it is essential to study the underlying mechanisms responsible for such toxicity. Furthermore, closer attention toward clinical outcomes is required to screen various ARV regimens for their association with HAND and other comorbidities. A growing body of literature also indicates a possible role of accelerated aging in the antiretroviral therapy-associated neurotoxicity. Lastly, owing to high pill burden, multiple drugs in the HIV treatment also invite a possible role of drug-drug interaction via various cytochrome P450 enzymes. The particular emphasis of this review is to highlight the need to identify alternative approaches in reducing the CNS toxicity of the ARV drugs in HIV-infected individuals.

Adverse Drug Reactions and Clinical Outcomes in Patients Initiated on Antiretroviral Therapy: A Prospective Cohort Study From Ethiopia

INTRODUCTION

In Ethiopia, the use of antiretroviral therapy (ART) has been scaled up for HIV/AIDS over the past decade. Adverse drug reactions (ADRs) associated with ART pose a unique challenge in the treatment of the infection in this resource-limited setting.

OBJECTIVES

The aims of this study were to examine the incidence and nature of ADRs, identify the risk factors associated with the development of ADRs, and assess their impact on treatment outcomes.

METHODS

A prospective cohort study was conducted in adult patients (≥18 years of age) with HIV/AIDS who commenced ART. All ADRs in the first 12 months of therapy were recorded, and the severity, causality, and preventability assessed. The impact of severe ADRs on self-reported adherence, immunological, and body mass index (BMI) outcomes were assessed.

RESULTS

Of the 211 patients included in the analysis, 181 (85.7 %) experienced at least one ADR and 66 (31.3 %) experienced at least one severe ADR within 12 months of commencing ART (incidence rates for any ADR and severe ADR of 14.8 and 3.2 per 100 person-months, respectively). Logistic regression analysis indicated that taking zidovudine-containing regimens (odds ratio [OR] 4.2, 95 % confidence interval [CI] 2.1-8.4) or being unemployed (OR 2.2, 95 % CI 1.1-4.3) were independent predictors of experiencing severe ADRs. Patients who experienced a severe ADR were less likely (OR 0.4, 95 % CI 0.2-0.9) to be ≥90 % adherent to ART. The mean gain in BMI was significantly lower in patients with severe ADRs after 3 and 12 months of therapy.

CONCLUSIONS

ADRs were common within the first 3 months in patients initiated on ART. Severe ADRs were negatively associated with self-reported adherence and gain in BMI. Measures need to be implemented to routinely monitor for severe ADRs to improve ART adherence and treatment outcomes.

The meningeal lymphatic system: a route for HIV brain migration?

Two innovative studies recently identified functional lymphatic structures in the meninges that may influence the development of HIV-associated neurological disorders (HAND). Until now, blood vessels were assumed to be the sole transport system by which HIV-infected monocytes entered the brain by bypassing a potentially hostile blood-brain barrier through inflammatory-mediated semi-permeability. A cascade of specific chemokine signals promote monocyte migration from blood vessels to surrounding brain tissues via a well-supported endothelium, where the cells differentiate into tissue macrophages capable of productive HIV infection. Lymphatic vessels on the other hand are more loosely organized than blood vessels. They absorb interstitial fluid from bodily tissues where HIV may persist and exchange a variety of immune cells (CD4(+) T cells, monocytes, macrophages, and dendritic cells) with surrounding tissues through discontinuous endothelial junctions. We propose that the newly discovered meningeal lymphatics are key to HIV migration among viral reservoirs and brain tissue during periods of undetectable plasma viral loads due to suppressive combinational antiretroviral therapy, thus redefining the migration process in terms of a blood-lymphatic transport system.

Incidence and predictors of adverse drug events in an African cohort of HIV-infected adults treated with efavirenz

INTRODUCTION

Adverse drug reactions associated with efavirenz (EFV) therapy are poorly described beyond the first year of treatment. We aimed to describe the incidence and predictors of EFV-related adverse drug reactions (ADRs) in a cohort of adult Nigerian HIV-infected patients on antiretroviral therapy (ART).

METHODS

This retrospective cohort study utilized clinical data of HIV-1 infected adults (aged ≥15 years), commenced on efavirenz containing-regimen between January 2004 and December 2011. The time-dependent occurrence of clinical adverse events as defined by the World Health Organization was analyzed by Cox regression analysis.

RESULTS

A total of 2920 patients with baseline median (IQR) age of 39 (33-46) years, largely made up of men (78%) were included in the study. During 8834 person-years of follow up, 358 adverse drug events were reported; the incidence rate was 40.3 ADRs per 1000 person-years of treatment. Lipodystrophy and neuropsychiatric disorders were the most common ADRs with incidences of 63 and 30 per 1000 patients respectively. About one-third of the neuropsychiatric adverse events were within 12 months of commencement of ART. The risk of neuropsychiatric ADRs was independently predicted for women [adjusted hazard ratio (aHR) 9.05; 95% CI: 5.18-15.82], those aged <40 years (aHR 2.59; 95% CI: 1.50-4.45), advanced HIV disease (WHO stage 3 or 4) [aHR 2.26; 95% CI: 1.37-3.72], and zidovudine [aHR 2.21; 95% CI: 1.27-3.83] or stavudine [aHR 4.22; 95% CI: 1.99-8.92] containing regimen compared to tenofovir.

CONCLUSION

Neuropsychiatric adverse drug events associated with efavirenz-based ART had both early and late onset in our clinical cohort of patients on chronic EFV therapy. Continuous neuropsychiatric assessment for improved detection and management of neuropsychiatric ADRs is recommended in resource-limited settings where the use of efavirenz-based regimens has been scaled up.

Tetronic® 904-containing polymeric micelles overcome the overexpression of ABCG2 in the blood-brain barrier of rats and boost the penetration of the antiretroviral efavirenz into the CNS

AIM

To assess the involvement of ABCG2 in the pharmacokinetics of efavirenz in the blood-brain barrier (BBB) and investigate a nanotechnology strategy to overcome its overexpression under a model of chronic oral administration. Materials & methods A model of chronic efavirenz (EFV) administration was established in male Sprague-Dawley rats treated with a daily oral dose over 5 days. Then, different treatments were conducted and drug concentrations in plasma and brain measured.

RESULTS

Chronic treatment with oral EFV led to the overexpression of ABCG2 in the BBB that was reverted after a brief washout period. Moreover, gefitinib and the polymeric amphiphile Tetronic(®) 904 significantly inhibited the activity of the pump and potentiated the accumulation of EFV in CNS. The same effect was observed when the drug was administered within mixed micelles containing TetronicT904 as the main component.

CONCLUSION

Tetronic 904-containing polymeric micelles overcame the overexpression of ABCG2 in the BBB caused by chronic administration of EFV then boosting its penetration into the CNS.

Antiretroviral Therapy Outcomes in Patients with Severe Mental Illness

A retrospective cohort analysis was performed to describe outcomes and retention in care on antiretroviral therapy (ART) of 53 patients with severe mental illness (SMI). Diagnoses were psychosis secondary to HIV (24 patients), psychosis not otherwise specified (12), mania with or without psychosis (9), depression with psychotic features (4), and schizophrenia and bipolar mood disorder (2 each). The median baseline CD4 count was 66/mm(3) and viral load was 5.4 log10 copies/mL. Thirteen (25%) patients were lost to follow-up (10 within 6 months), 3 were transferred out, and 3 died. By week 96, 29 (85%) of 34 (64%) patients still in care had a viral load <400 copies/mL and 26 (76%) a viral load <25 copies/mL. Median CD4 count increased to 307/mm(3). Twenty-seven of 34 patients discontinued antipsychotic medication. Patients with SMI and advanced HIV infection responded well to ART. The first 6 months was important for retention in care.

Efficacy and safety of lersivirine versus etravirine for the treatment of HIV-1 infection in patients with prior non-nucleoside reverse transcriptase inhibitor (NNRTI) use and evidence of NNRTI resistance: a randomized phase 2B trial

OBJECTIVE

To assess the efficacy and safety of lersivirine versus etravirine in patients with HIV-1 and prior non-nucleoside reverse transcriptase inhibitor (NNRTI) use and evidence of NNRTI resistance.

METHODS

In this 96-week, phase 2b study, 97 patients were randomized and treated with lersivirine 750 mg qd (n = 31), lersivirine 1,000 mg qd (n = 32), and etravirine 200 mg bid (n = 34), plus one optimized nucleoside reverse transcriptase inhibitor and darunavir/ritonavir 600/100 mg bid. The primary endpoint was the percentage of patients with HIV-1 RNA <50 copies/mL at week 24.

RESULTS

At week 24, HIV-1 RNA <50 copies/mL was achieved by fewer patients receiving lersivirine 750 mg (48.4%) and 1,000 mg (43.8%) qd compared with etravirine 200 mg qd (67.7%) (intention to treat [ITT], missing/switch/discontinuation equals failure [MSDF]). At week 48, HIV-1 RNA <50 copies/mL and <400 copies/mL were also achieved by fewer patients receiving lersivirine 750 mg (41.9% and 41.9%, respectively) and 1,000 mg (31.3% and 34.4%, respectively) qd compared with etravirine 200 mg bid (61.8% and 70.6%, respectively) (ITT, MSDF). Least squares means (SE) change from baseline in log transformed HIV-1 RNA at week 48 was -1.42 (0.27) and -0.95 (0.28) copies/mL for lersivirine 750 mg and 1,000 mg qd, respectively, versus -2.02 (0.26) copies/mL for etravirine 200 mg bid (ITT). Lersivirine and etravirine were generally safe and well-tolerated.

CONCLUSIONS

Lersivirine 750 mg and 1,000 mg qd was associated with lower rates of viral suppression at week 24 and week 48 versus etravirine in patients with prior NNRTI use and evidence of NNRTI resistance. No new safety signals were detected.

Substantial effect of efavirenz monotherapy on bilirubin levels in healthy volunteers

Background

Efavirenz exhibits multiple interactions with drug-metabolizing enzymes and transporters, and for this reason efavirenz-based HIV therapy is associated with altered pharmacokinetics of coadministered drugs. Probably by the same mechanism, efavirenz-based HIV therapy affects the disposition of endogenous compounds, but this effect is difficult to directly link with efavirenz because it is used in combination with other drugs.

Objectives

To explore the effect of efavirenz monotherapy on biochemical laboratory values in a clinical trial of healthy volunteers.

Methods

Men and women (aged 18–49 years) with body mass index ≤32 who were assessed to be healthy based on medical history, physical examination, and standard laboratory screening received a single (600 mg) and multiple doses (600 mg/d for 17 days) of efavirenz orally. This trial was designed to determine the pharmacokinetics and drug interactions of efavirenz. As part of this study, analysis of serum chemistries that were measured at study entry (screening) and 1 week after completion of the multiple dose study (exit) is reported.

Results

Data from 60 subjects who fully completed and 13 subjects who partially completed the study are presented. Total bilirubin was substantially reduced at exit (by ~30%, with large intersubject variability) compared with screening values (P < 0.0001). The percent changes were in part explained by the intersubject differences in baseline total bilirubin because there was a significant correlation between baseline (screening) values and percent change at exit (r = 0.50; P < 0.0001). Hemoglobin and absolute neutropenia were also substantially decreased at exit compared with screening, but this may be due to intensive blood sampling rather than direct effect of efavirenz on these parameters. No significant correlation was found between percent change in hemoglobin versus percent change in bilirubin, indicating the effect of efavirenz on bilirubin is independent of its effects on hemoglobin.

Conclusions

Efavirenz monotherapy significantly lowers plasma total bilirubin concentration in healthy volunteers independent of its effect on hemoglobin, probably through its effects on bilirubin metabolism and transport (uptake and efflux). These findings help explain reversal by efavirenz of hyperbilirubinemia induction observed by some protease inhibitor antiretroviral drugs (eg, atazanavir). Besides its well-documented role on drug interactions, efavirenz may alter the disposition of endogenous compounds relevant in physiologic homeostasis through its interaction with drug metabolizing enzymes and/or drug transporters. ClinicalTrials.gov identifier: NCT00668395.

Neurological and psychiatric adverse effects of antiretroviral drugs

Antiretroviral drugs are associated with a variety of adverse effects on the central and peripheral nervous systems. The frequency and severity of neuropsychiatric adverse events is highly variable, with differences between the antiretroviral classes and amongst the individual drugs in each class. In the developing world, where the nucleoside reverse transcriptase inhibitor (NRTI) stavudine remains a commonly prescribed antiretroviral, peripheral neuropathy is an important complication of treatment. Importantly, this clinical entity is often difficult to distinguish from human immunodeficiency virus (HIV)-induced peripheral neuropathy. Several clinical trials have addressed the efficacy of various agents in the treatment of NRTI-induced neurotoxicity. NRTI-induced neurotoxicity is caused by inhibition of mitochondrial DNA polymerase. This mechanism is also responsible for the mitochondrial myopathy and lactic acidosis that occur with zidovudine. NRTIs, particularly zidovudine and abacavir, may also cause central nervous system (CNS) manifestations, including mania and psychosis. The non-nucleoside reverse transcriptase inhibitor (NNRTI) efavirenz is perhaps the antiretroviral most commonly associated with CNS toxicity, causing insomnia, irritability and vivid dreams. Recent studies have suggested that the risk of developing these adverse effects is increased in patients with various cytochrome P450 2B6 alleles. Protease inhibitors cause perioral paraesthesias and may indirectly increase the relative risk of stroke by promoting atherogenesis. HIV integrase inhibitors, C-C chemokine receptor type 5 (CCR5) inhibitors and fusion inhibitors rarely cause neuropsychiatric manifestations.

Iatrogenic neurology

Iatrogenic disease is one of the most frequent causes of hospital admissions and constitutes a growing public health problem. The most common type of iatrogenic neurologic disease is pharmacologic, and the central and peripheral nervous systems are particularly vulnerable. Despite this, iatrogenic disease is generally overlooked as a differential diagnosis among neurologic patients. The clinical picture of pharmacologically mediated iatrogenic neurologic disease can range from mild to fatal. Common and uncommon forms of drug toxicity are comprehensively addressed in this chapter. While the majority of neurologic adverse effects are listed and referenced in the tables, the most relevant issues are further discussed in the text.

Animal models for depression associated with HIV-1 infection

Antiretroviral therapy has greatly extended the lifespan of people living with human immunodeficiency virus (PLHIV). As a result, the long-term effects of HIV infection, in particular those originating in the central nervous system (CNS), such as HIV associated depression, have gained importance. Animal models for HIV infection have proved very useful for understanding the disease and developing treatment strategies. However, HIV associated depression remains poorly understood and so far there is neither a fully satisfactory animal model, nor a pathophysiologically guided treatment for this condition. Here we review the neuroimmunological, neuroendocrine, neurotoxic and neurodegenerative basis for HIV depression and discuss strategies for employing HIV animal models, in particular humanized mice which are susceptible to HIV infection, for the study of HIV depression.

The HIV antiretroviral drug efavirenz has LSD-like properties

Anecdotal reports have surfaced concerning misuse of the HIV antiretroviral medication efavirenz ((4S)-6-chloro-4-(2-cyclopropylethynyl)-4-(trifluoromethyl)-2,4-dihydro-1H-3,1-benzoxazin-2-one) by HIV patients and non-infected teens who crush the pills and smoke the powder for its psychoactive effects. Molecular profiling of the receptor pharmacology of efavirenz pinpointed interactions with multiple established sites of action for other known drugs of abuse including catecholamine and indolamine transporters, and GABAA and 5-HT(2A) receptors. In rodents, interaction with the 5-HT(2A) receptor, a primary site of action of lysergic acid diethylamine (LSD), appears to dominate efavirenz's behavioral profile. Both LSD and efavirenz reduce ambulation in a novel open-field environment. Efavirenz occasions drug-lever responding in rats discriminating LSD from saline, and this effect is abolished by selective blockade of the 5-HT(2A) receptor. Similar to LSD, efavirenz induces head-twitch responses in wild-type, but not in 5-HT(2A)-knockout, mice. Despite having GABAA-potentiating effects (like benzodiazepines and barbiturates), and interactions with dopamine transporter, serotonin transporter, and vesicular monoamine transporter 2 (like cocaine and methamphetamine), efavirenz fails to maintain responding in rats that self-administer cocaine, and it fails to produce a conditioned place preference. Although its molecular pharmacology is multifarious, efavirenz's prevailing behavioral effect in rodents is consistent with LSD-like activity mediated via the 5-HT(2A) receptor. This finding correlates, in part, with the subjective experiences in humans who abuse efavirenz and with specific dose-dependent adverse neuropsychiatric events, such as hallucinations and night terrors, reported by HIV patients taking it as a medication.

[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.

8-Hydroxy-efavirenz, the primary metabolite of the antiretroviral drug Efavirenz, stimulates the glycolytic flux in cultured rat astrocytes

In active antiretroviral therapy antiretroviral drugs are employed for the restoration of a functional immune system in patients suffering from the acquired immunodeficiency syndrome. However, potential adverse effects of such compounds to brain cells are discussed in connection with the development of neurocognitive impairments in patients. To investigate potential effects of antiretroviral drugs on cell viability and the glycolytic flux of brain cells, astrocyte-rich primary cultures were exposed to various antiretroviral compounds, including the non-nucleoside reverse transcriptase inhibitor efavirenz. In a concentration of 10 μM, neither efavirenz nor any of the other investigated antiretroviral compounds acutely compromised the cell viability nor altered glucose consumption or lactate production. In contrast, the primary metabolite of efavirenz, 8-hydroxy-efavirenz, stimulated the glycolytic flux in viable astrocytes in a time- and concentration-dependent manner with half-maximal and maximal effects at concentrations of 5 and 10 μM, respectively. The stimulation of glycolytic flux by 8-hydroxy-efavirenz was not additive to that obtained for astrocytes that were treated with the respiratory chain inhibitor rotenone and was abolished by removal of extracellular 8-hydroxy-efavirenz. In a concentration of 10 μM, 8-hydroxy-efavirenz and efavirenz did not affect mitochondrial respiration, while both compounds lowered in a concentration of 60 μM significantly the oxygen consumption by mitochondria that had been isolated form cultured astrocytes, suggesting that the stimulation of glycolytic flux by 8-hydroxy-efavrienz is not caused by direct inhibition of respiration. The observed alteration of astrocytic glucose metabolism by 8-hydroxy-efavirenz could contribute to the adverse neurological side effects reported for patients that are chronically treated with efavirenz-containing medications.

Neuronal toxicity of efavirenz: a systematic review

INTRODUCTION

Efavirenz commonly causes early neuropsychiatric side effects, but tolerance develops in most patients. There is emerging evidence that efavirenz use may damage neurons, which could result in impaired neurocognitive performance.

AREAS COVERED

The authors conducted a systematic review using the PubMed database, references cited by other articles and conference web sites to determine if there is evidence that efavirenz may contribute to cognitive impairment by damaging nerve cells.

EXPERT OPINION

There is weak clinical evidence suggesting that efavirenz use may worsen neurocognitive impairment or be associated with less improvement in neurocognitive impairment than other antiretrovirals. Efavirenz, especially its major metabolite 8-hydroxy-efavirenz, is toxic in neuron cultures at concentrations found in the cerebrospinal fluid. Extensive metabolizers of efavirenz may therefore be more likely to develop efavirenz toxicity by forming more 8-hydroxy-efavirenz. Several potential mechanisms exist to explain the observed efavirenz neurotoxicity, including altered calcium hemostasis, decreases in brain creatine kinase, mitochondrial damage, increases in brain proinflammatory cytokines and involvement of the cannabinoid system. There is a need for large randomized controlled trials to determine if the neuronal toxicity induced by efavirenz results in clinically significant neurological impairment.

Efficacy and safety of lersivirine (UK-453,061) versus efavirenz in antiretroviral treatment-naive HIV-1-infected patients: week 48 primary analysis results from an ongoing, multicenter, randomized, double-blind, phase IIb trial

OBJECTIVE

A 96-week clinical study was planned to estimate the antiviral activity and safety of lersivirine in treatment-naive HIV-1-infected patients.

METHODS

This ongoing international, multicenter, double-blind, randomized, Phase IIb exploratory study evaluates the efficacy and safety of 2 doses of lersivirine or 1 of efavirenz, each combined with tenofovir disoproxil fumarate/emtricitabine. Patients were randomized 1:1:1 to receive lersivirine (500 or 750 mg once daily) or efavirenz (600 mg once daily), each administered with tenofovir disoproxil fumarate/emtricitabine (300 mg/200 mg, once daily). The primary endpoint is the proportion of patients with HIV-1 RNA <50 copies per milliliter (missing/discontinuation = failure) at week 48.

RESULTS

For the 193 patients in the study, baseline mean plasma HIV-1 RNA was 4.7 log10 copies per milliliter, and median CD4 cell count was 312 cells per cubic millimeter. At week 48, the percentage of patients with HIV-1 RNA <50 copies per milliliter was 78.5% (51/65), 78.5% (51/65), and 85.7% (54/63) in the lersivirine 500 mg, 750 mg, and efavirenz groups, respectively. CD4 cell count changes from baseline were similar across groups. Virologic failure occurred in 7 patients (11%) in each of the lersivirine groups and 3 patients (5%) in the efavirenz group. The pattern of lersivirine resistance was distinct from other nonnucleoside reverse transcriptase inhibitors. Overall incidences of all-causality treatment-related or grade 3/4 adverse events (AEs) or AE-related discontinuations were lower with lersivirine than with efavirenz, and serious AEs occurred at similar rates across treatment groups.

CONCLUSIONS

Both lersivirine doses showed broadly comparable efficacy to efavirenz over 48 weeks in treatment-naive patients, with different AE profiles from efavirenz.

Pharmacokinetic optimization of antiretroviral therapy in pregnancy

Antiretroviral therapy suppresses replication of HIV allowing restoration and/or preservation of the immune system. Providing combination antiretroviral therapy during pregnancy can treat maternal HIV infection and/or reduce perinatal HIV transmission. However, providing treatment to pregnant women is challenging due to physiological changes that can alter antiretroviral pharmacokinetics. Suboptimal drug exposure can result in HIV RNA rebound, the selection of resistant virus or an increased risk of HIV-1 transmission to the infant. Increased drug exposure can produce unwarranted maternal adverse effects and/or fetal toxicity. Subsequently, dose adjustments may be necessary during pregnancy to achieve comparable antiretroviral exposure to non-pregnant adults. For several antiretrovirals, systemic exposure is decreased during the last trimester of pregnancy. By 6-12 weeks postpartum, concentrations return to those prior to pregnancy. Also, the extent of antiretroviral placental transfer to the fetus and degree of antiretroviral excretion into breast milk varies within, and between, antiretroviral drug classes. It is necessary to consider the pharmacological characteristics of each antiretroviral when optimizing combination therapy during pregnancy to treat maternal HIV infection and prevent perinatal HIV transmission.

CSF penetration by antiretroviral drugs

Severe HIV-associated neurocognitive disorders (HAND), such as HIV-associated dementia, and opportunistic CNS infections are now rare complications of HIV infection due to comprehensive highly active antiretroviral therapy (HAART). By contrast, mild to moderate neurocognitive disorders remain prevalent, despite good viral control in peripheral compartments. HIV infection seems to provoke chronic CNS injury that may evade systemic HAART. Penetration of antiretroviral drugs across the blood-brain barrier might be crucial for the treatment of HAND. This review identifies and evaluates the available clinical evidence on CSF penetration properties of antiretroviral drugs, addressing methodological issues and discussing the clinical relevance of drug concentration assessment. Although a substantial number of studies examined CSF concentrations of antiretroviral drugs, there is a need for adequate, well designed trials to provide more valid drug distribution profiles. Neuropsychological benefits and neurotoxicity of potentially CNS-active drugs require further investigation before penetration characteristics will regularly influence therapeutic strategies and outcome.

[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.

Medication safety in rehabilitation medicine

Rehabilitation medicine is practiced in a variety of settings. Physiatrists are an integral part of the care provided in many of these settings and are often consulted to provide diagnostic and therapeutic services and expertise to individuals with a variety of diagnoses. In this role, it is imperative that physiatrists have a working knowledge of various medications as well as the principles of medication safety. This article provides a foundation in the general and specific aspects of medication safety as they apply to the practice of rehabilitation medicine.

HIV-associated neurological disorders: a guide to pharmacotherapy

In the era of highly active antiretroviral therapy (HAART), HIV-1-associated neurocognitive disorder (HAND) continues to be a common and significant morbidity among individuals infected with HIV. The term HAND encompasses a spectrum of progressively severe CNS involvement, ranging from asymptomatic neurocognitive impairment and minor neurocognitive disorder through to the most severe form of HIV-associated dementia (HAD). While the incidence of HAD has declined significantly with HAART, the milder forms of HAND persist. In addition, HAND now develops in individuals with less advanced immunosuppression. The reasons for the persistence of milder forms of HAND in individuals treated with HAART are not entirely known. There are several hypotheses to explain this phenomenon that include the legacy effect, a failure of antiretroviral agents to reverse neurological damage, poor access of antiretroviral agents to the CNS, chronic systemic immune activation associated with microbial translocation products, sustained CNS inflammation, the improved survival of HIV-seropositive individuals and the possible contribution from aging, amyloid deposition and other co-morbidities. In contrast, the incidence of HIV-associated CNS opportunistic processes including progressive multifocal leukoencephalopathy, tuberculosis, CNS toxoplasmosis, cytomegalovirus encephalitis, cryptococcosis and primary CNS lymphoma has declined dramatically with the introduction of HAART. This review briefly summarizes our current understanding of HAND and the pathological mechanisms involved, namely direct injury from HIV-1 and viral proteins, indirect neurotoxicity from proinflammatory cytokines and chronic, sustained immune activation in the CNS. To date, only HAART has been shown to benefit HAND despite numerous controlled trials of adjunctive 'anti-inflammatory' agents. Although HAART has a profound impact on the incidence and severity of HAND, there exists a 'therapeutic gap' as even HAART that is effective at inducing durable virological suppression may only partially reverse HAND. In addition, there may be potential CNS adverse effects of antiretroviral agents. There is an ongoing multicentre clinical trial to investigate the role of the CNS Penetration-Effectiveness index, an indicator of drug permeability and availability in the CNS, to help guide the choice of antiretroviral agents in the treatment of HAND. With recent recommendations for earlier treatment intervention with HAART for HIV-1 infection, it remains to be seen the effects of this on HAND. There is an urgent need to better define the therapeutic guidelines for the prevention and treatment of HAND.

Individualization of antiretroviral therapy

Antiretroviral therapy (ART) has evolved considerably over the last three decades. From the early days of monotherapy with high toxicities and pill burdens, through to larger pill burdens and more potent combination therapies, and finally, from 2005 and beyond where we now have the choice of low pill burdens and once-daily therapies. More convenient and less toxic regimens are also becoming available, even in resource-poor settings. An understanding of the individual variation in response to ART, both efficacy and toxicity, has evolved over this time. The strong association of the major histocompatibility class I allele HLA-B*5701 and abacavir hypersensitivity, and its translation and use in routine HIV clinical practice as a predictive marker with 100% negative predictive value, has been a success story and a notable example of the challenges and triumphs in bringing pharmacogenetics to the clinic. In real clinical practice, however, it is going to be the exception rather than the rule that individual biomarkers will definitively guide patient therapy. The need for individualized approaches to ART has been further increased by the importance of non-AIDS comorbidities in HIV clinical practice. In the future, the ideal utilization of the individualized approach to ART will likely consist of a combined approach using a combination of knowledge of drug, virus, and host (pharmacogenetic and pharmacoecologic [factors in the individual’s environment that may be dynamic over time]) information to guide the truly personalized prescription. This review will focus on our knowledge of the pharmacogenetics of the efficacy and toxicity of currently available antiretroviral agents and the current and potential utility of such information and approaches in present and future HIV clinical care.

Drug safety evaluation of maraviroc for the treatment of HIV infection

INTRODUCTION

Maraviroc is the only C-chemokine receptor 5 (CCR5) antagonist approved for the treatment of infection with HIV. This article reviews the safety and efficacy of maraviroc in the treatment of HIV infection.

AREAS COVERED

The PubMed database was searched using the keywords 'maraviroc' and 'HIV'. In addition, conference proceedings from CROI, IAS and EACS meetings were searched for maraviroc clinical trials. The PubMed search revealed one Phase IIb - III clinical trial in treatment-naive HIV(+) patients (MERIT) and three Phase IIb - III randomized clinical trials (RCTs) in treatment-experienced patients (MOTIVATE 1 and 2, A4001029). All RCTs showed an excellent safety profile for maraviroc in the treatment of HIV-1 infection. However, long-term (> 3 years) safety data generated on maraviroc therapy are still scarce. Based on the findings from RCTs so far, no relevant toxicities and co-morbidities such as coronary heart disease or hepatotoxicity have been described. The overall CD4(+) cell count increase resulting from a maraviroc-containing regimen appears to be higher than those seen with other antiretroviral regimens. However, the significance remains controversial. To date, maraviroc has shown a potent and durable virological efficacy profile for the treatment of HIV-1 infection. The only use of maraviroc depends on pretreatment testing for CCR5 tropism.

EXPERT OPINION

Maraviroc is a generally safe and well-tolerated medication for the treatment of HIV-1 infection with a unique mechanism of action. Long-term (i.e., > 5 years) risks are not known and have to be carefully monitored.

Minimum effective plasma concentration of efavirenz in treatment-naïve Chinese HIV-infected patients

To assess the relationship between mean efavirenz (EFV) plasma concentration and clinical effect during the first 48 weeks of combination antiretroviral therapy (cART), the baseline CD4 cell count was recorded and plasma EFV concentration and CD4 cell count were measured every 12 weeks. HIV-RNA viral load was determined in the 48th week of cART. In total, 42 subjects were recruited and grouped according to their mean concentration of EFV during the study period: groups A, B and C with EFV concentrations (mean) <2 mg/L (1.8 mg/L), 2-4 mg/L (2.9 mg/L) and >4 mg/L (5.5 mg/L), respectively. The CD4 cell counts in group C increased more quickly than in groups B and A, although this was not statistically significant (211 ± 176/μL versus 151 ± 145/μL and 172 ± 105/μL, respectively; P = 0.799). Groups B and C had higher rates of HIV viral load suppression than group A (P = 0.017). For treatment-naïve Chinese HIV-infected patients, EFV plasma concentrations above 2 mg/L appear to suppress HIV replication more effectively than concentrations below 2 mg/L.

Randomized, phase 2 evaluation of two single-tablet regimens elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate versus efavirenz/emtricitabine/tenofovir disoproxil fumarate for the initial treatment of HIV infection

OBJECTIVE

To assess the safety and efficacy of two, single-tablet regimens for the initial treatment of HIV infection.

DESIGN

Phase 2, randomized, double-blind, double-dummy, multicenter, active-controlled study.

METHODS

Antiretroviral treatment-naive adults with a screening HIV-1 RNA at least 5000 copies/ml and a CD4 cell count more than 50 cells/μl were randomized 2: 1 to receive fixed-dose combination tablets of elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate (EVG/COBI/FTC/TDF; N = 48) or efavirenz/emtricitabine/tenofovir disoproxil fumarate (EFV/FTC/TDF; n = 23) for 48 weeks. The primary endpoint was proportion of participants with HIV-1 RNA less than 50 copies/ml at week 24.

RESULTS

Participants receiving EVG/COBI/FTC/TDF exhibited a more rapid decline in HIV-1 RNA and a greater proportion suppressed viral load to less than 50 copies/ml than participants receiving EFV/FTC/TDF. Both EVG/COBI/FTC/TDF and EFV/FTC/TDF resulted in high rates of viral suppression and increases in CD4 cell count. Ninety and 83% of participants suppressed HIV-1 RNA to less than 50 copies/ml both at the 24-week and 48-week visits for EVG/COBI/FTC/TDF and EFV/FTC/TDF, respectively. Once-daily administration of EVG/COBI/FTC/TDF provided a mean EVG trough concentration 10-fold over its protein binding-adjusted IC(95) across study visits. EVG/FTC/TDF/GS-9350 was generally well tolerated with a lower rate of drug-related central nervous system (17%) and psychiatric (10%) adverse events versus EFV/FTC/TDF (26 and 44%, respectively). Decreases in estimated glomerular filtration rate occurred within the first few weeks of dosing in participants receiving EVG/COBI/FTC/TDF, remained within the normal range and did not progress at week 24 or 48; no participant experienced a clinical adverse event or discontinued study drug due to changes in serum creatinine or renal function.

CONCLUSION

Once-daily EVG/COBI/FTC/TDF achieved and maintained a high rate of virologic suppression with fewer central nervous system and psychiatric adverse events compared to a current standard-of-care regimen of EFV/FTC/TDF.

Neurocognitive impairment and HIV risk factors: a reciprocal relationship

Cognitive impairment among populations at risk for HIV poses a significant barrier to managing risk behaviors. The impact of HIV and several cofactors, including substance abuse and mental illness, on cognitive function is discussed in the context of HIV risk behaviors, medication adherence, and risk-reduction interventions. Literature suggests that cognitive impairment is intertwined in a close, reciprocal relationship with both risk behaviors and medication adherence. Not only do increased risk behaviors and suboptimal adherence exacerbate cognitive impairment, but cognitive impairment also reduces the effectiveness of interventions aimed at optimizing medication adherence and reducing risk. In order to be effective, risk-reduction interventions must therefore take into account the impact of cognitive impairment on learning and behavior.

Metabolic and neurologic consequences of chronic lopinavir/ritonavir administration to C57BL/6 mice

It is well established that HIV antiretroviral drugs, particularly protease inhibitors, frequently elicit a metabolic syndrome that may include hyperlipidemia, lipodystrophy, and insulin resistance. Metabolic dysfunction in non-HIV-infected subjects has been repeatedly associated with cognitive impairment in epidemiological and experimental studies, but it is not yet understood if antiretroviral therapy-induced metabolic syndrome might contribute to HIV-associated neurologic decline. To determine if protease inhibitor-induced metabolic dysfunction in mice is accompanied by adverse neurologic effects, C57BL/6 mice were given combined lopinavir/ritonavir (50/12.5-200/50 mg/kg) daily for 3 weeks. Data show that lopinavir/ritonavir administration caused significant metabolic derangement, including alterations in body weight and fat mass, as well as dose-dependent patterns of hyperlipidemia, hypoadiponectinemia, hypoleptinemia, and hyperinsulinemia. Evaluation of neurologic function revealed that even the lowest dose of lopinavir/ritonavir caused significant cognitive impairment assessed in multi-unit T-maze, but did not affect motor functions assessed as rotarod performance. Collectively, our results indicate that repeated lopinavir/ritonavir administration produces cognitive as well as metabolic impairments, and suggest that the development of selective aspects of metabolic syndrome in HIV patients could contribute to HIV-associated neurocognitive disorders.

A review of the safety and tolerability profile of the next-generation NNRTI etravirine

The next-generation nonnucleoside reverse transcriptase inhibitor (NNRTI) etravirine (TMC125) has demonstrated durable virologic efficacy in clinical trials involving >1000 treatment-experienced, NNRTI-resistant, HIV-1-infected patients. In this clinical safety review, we show etravirine to be well tolerated with a proven safety record. The nature and magnitude of adverse events observed during treatment suggest that etravirine may offer improved tolerability over existing antiretrovirals, including NNRTIs. Notably, adverse events reported with etravirine treatment are generally mild to moderate in severity. Rash has been shown to occur with a higher incidence in etravirine-treated patients versus placebo, but cases are generally mild to moderate, occur within the first few weeks, and resolve with continued use. In addition, the rate of adverse event-related discontinuations is low with etravirine. In summary, the safety and tolerability profile of etravirine, combined with its virologic efficacy, suggest that the drug may be a valuable option for treatment-experienced patients with HIV-1 infection.

Efavirenz directly modulates the oestrogen receptor and induces breast cancer cell growth

OBJECTIVES

Efavirenz-based HIV therapy is associated with breast hypertrophy and gynaecomastia. Here, we tested the hypothesis that efavirenz induces gynaecomastia through direct binding and modulation of the oestrogen receptor (ER).

METHODS

To determine the effect of efavirenz on growth, the oestrogen-dependent, ER-positive breast cancer cell lines MCF-7, T47D and ZR-75-1 were treated with efavirenz under oestrogen-free conditions in the presence or absence of the anti-oestrogen ICI 182,780. Cells treated with 17β-oestradiol in the absence or presence of ICI 182,780 served as positive and negative controls, respectively. Cellular growth was assayed using the crystal violet staining method and an in vitro receptor binding assay was used to measure the ER binding affinity of efavirenz.

RESULTS

Efavirenz induced growth in MCF-7 cells with an estimated effective concentration for half-maximal growth (EC(50)) of 15.7 μM. This growth was reversed by ICI 182,780. Further, efavirenz binds directly to the ER [inhibitory concentration for half maximal binding (IC(50)) of ∼52 μM] at a roughly 1000-fold higher concentration than observed with 17β-oestradiol.

CONCLUSIONS

Our data suggest that efavirenz-induced gynaecomastia may be caused, at least in part, by drug-induced ER activation in breast tissues.

Clinical impact of patient population differences and genomic variation in efavirenz therapy

Guidelines for use of antiretroviral agents presently recommend first-line treatments with nonnucleoside reverse transcriptase inhibitor-based regimens. Efavirenz is the standard-of-care comparator for nonnucleoside reverse transcriptase inhibitor-based antiretroviral therapy. As with many antiretroviral medications, efavirenz is subject to interindividual variation in metabolism, effectiveness, and tolerability. Demographic factors such as age, sex, and ethnicity have been demonstrated to influence this variability, but other underlying factors such as genetics, disease state, and concomitant drug use can also play a role. The clinical impactions of these factors are only beginning to be understood. Although significant advances have led to a greater understanding of interactions between genetic and host factors that influence the efficacy and toxicity of efavirenz, providers should not withhold treatment of HIV infection with an efavirenz-based regimen on the basis of racial or ethic categorizations.

Antiretroviral therapy and central nervous system HIV type 1 infection

Central nervous system (CNS) human immunodeficiency virus type 1 (HIV-1) infection begins during primary viremia and continues throughout the course of untreated systemic infection. Although frequently accompanied by local inflammatory reactions detectable in cerebrospinal fluid (CSF), CNS HIV-1 infection usually is not clinically apparent. In a minority of patients, CNS HIV-1 infection evolves into encephalitis during the late stages of systemic infection, which compromises brain function and presents clinically as acquired immunodeficiency syndrome dementia complex (ADC). Combination antiretroviral therapy (ART) has had a major impact on all aspects of CNS HIV-1 infection and disease. In those with asymptomatic infection, ART usually effectively suppresses HIV-1 in CSF and markedly reduces the incidence of symptomatic ADC. In those presenting with ADC, ART characteristically prevents neurological progression and leads to variable, and at times substantial, recovery. Similarly, treatment has reduced CNS opportunistic infections. With better control of these severe disorders, attention has turned to the possible consequences of chronic silent infection and the issue of whether indolent, low-grade brain injury might require earlier treatment intervention.

Impact of depression on HIV outcomes in the HAART era

Highly active antiretroviral therapy (HAART) has significantly decreased the morbidity and mortality of persons infected with HIV. The extent of the benefits, however, is not uniform, and certain factors including ethnicity, gender, baseline HIV viral load and CD4+ T lymphocyte count, adherence and intravenous drug abuse are associated with different immunological, virological and clinical outcomes. Mental health illness (MHI) and specifically depression may be associated with worse outcomes, although studies exploring the impact of MHI on HIV outcomes in both the pre-HAART and post-HAART eras have shown mixed results. The objective of the current paper is to review the available literature on the impact of MHI on HIV outcomes in the HAART era.