Adriana Andrade

A Pilot Study Assessing the Safety and Latency-Reversing Activity of Disulfiram in HIV-1–Infected Adults on Antiretroviral Therapy

BACKGROUND Transcriptionally silent human immunodeficiency virus type 1 (HIV-1) DNA persists in resting memory CD4(+) T cells despite antiretroviral therapy. In a primary cell model, the antialcoholism drug disulfiram has been shown to induce HIV-1 transcription in latently infected resting memory CD4(+) T cells at concentrations achieved in vivo. METHODS We conducted a single-arm pilot study to evaluate whether 500 mg of disulfiram administered daily for 14 days to HIV-1-infected individuals on stable suppressive antiretroviral therapy would result in reversal of HIV-1 latency with a concomitant transient increase in residual viremia or depletion of the latent reservoir in resting memory CD4(+) T cells. RESULTS Disulfiram was safe and well tolerated. There was a high level of subject-to-subject variability in plasma disulfiram levels. The latent reservoir did not change significantly (1.16-fold change; 95% confidence interval [CI], .70- to 1.92-fold; P = .56). During disulfiram administration, residual viremia did not change significantly compared to baseline (1.53-fold; 95% CI, .88- to 2.69-fold; P = .13), although residual viremia was estimated to increase by 1.88-fold compared to baseline during the postdosing period (95% CI, 1.03- to 3.43-fold; P = .04). In a post hoc analysis, a rapid and transient increase in viremia was noted in a subset of individuals (n = 6) with immediate postdose sampling (HIV-1 RNA increase, 2.96-fold; 95% CI, 1.29- to 6.81-fold; P = .01). CONCLUSIONS Administration of disulfiram to patients on antiretroviral therapy does not reduce the size of the latent reservoir. A possible dose-related effect on residual viremia supports future studies assessing the impact of higher doses on HIV-1 production. Disulfiram affects relevant signaling pathways and can be safely administered, supporting future studies of this drug.

Interactions between Natural Health Products and Antiretroviral Drugs: Pharmacokinetic and Pharmacodynamic Effects

Concurrent use of natural health products (NHPs) with antiretroviral drugs (ARVs) is widespread among human immunodeficiency virus-infected patients. This article reviews the clinical pharmacokinetic and pharmacodynamic interactions between NHPs and ARVs. Many NHPs are complex mixtures and are likely to contain organic compounds that may induce and/or inhibit drug metabolizing enzymes and drug transporters. Although the weight of evidence for the effects of certain NHPs varies and many studies of these products lack scientific rigor, it has been observed that St. Johns wort clearly induces cytochrome P450 3A4 and P-glycoprotein and reduces protease inhibitor and nonnucleoside reverse-transcriptase inhibitor concentrations, thereby increasing the likelihood of therapeutic failure. Limited clinical research suggests that intake of garlic and vitamin C results in reductions in ARV concentrations. The intake of milk thistle, Echinacea species, and goldenseal inhibits cytochrome P450 enzymes in vitro and may increase ARV concentrations, but by clinically unimportant amounts. Intake of fish oil reduces ARV-induced hypertriglyceridemia without significantly affecting lopinavir concentrations. Before recommending the use of NHPs as adjuncts to ARV use, studies should first exclude significant pharmacokinetic interactions and ensure that ARV efficacy is maintained.

Drug Interactions Involving Combination Antiretroviral Therapy and Other Anti-Infective Agents: Repercussions for Resource-Limited Countries

The scale-up of antiretroviral treatment (ART) in resource-poor countries has been impressive, both in its scope and in its impact. In 2003, 400,000 people in resource-limited settings were receiving antiretroviral drugs (ARVs); by 2006, this number had increased to 2 million people [1]. Treatment of common infections occurring with HIV is also increasing, as most HIV-infected persons live in areas where infectious diseases such as tuberculosis (TB) and malaria are prevalent. The use of over-the-counter and natural health products is also pervasive [2]. Therefore, the management of HIV infection in these settings will require multiple concurrent medications, with a potential for drug interactions and overlapping toxicities. Although in recent years there has been a significant expansion in access to ARVs in resource-poor countries, options are limited in most areas. In 2006, 95% of individuals receiving first-line ARVs in resource-poor settings were being treated with 1 of 4 fixed-dose regimens: stavudine (d4T) lamivudine (3TC) nevirapine (NVP); zidovudine (AZT) 3TC NVP; d4T 3TC efavirenz (EFV); or AZT 3TC EFV [1]. Currently, the World Health Organization (WHO) recommends a first-line regimen that includes a thiacytadine analogue (either 3TC or emtricitabine), a companion nucleoside reverse-transcriptase inhibitor (NRTI) (either AZT, tenofovir [TDF], abacavir [ABC], or d4T), and a nonNRTI (NNRTI) (either EFV or NVP) [3]. Second-line regimens include 2 previously unused NRTIs (didanosine, TDF, ABC, 3TC, and/or AZT) coupled with either a ritonavir (RTV)– boosted protease inhibitor (PI) (either lopinavir, saquinavir, indinavir, atazanavir, or fosamprenavir) or unboosted nelfinavir. Available antimicrobial drugs such as itraconazole, ketoconazole, clarithromycin, and rifampin have serious interactions or overlapping toxicities with ARVs. Cost, as well as political and infrastructural constraints, limits access to drugs—such as fluconazole, azithromycin, and rifabutin—that have fewer interactions [4]. Thus, even when drug interactions are well characterized, clinicians caring for HIV-infected patients have few options. Now that HIV treatment is available in many resource-limited countries, clinicians must understand the basic principles of drug metabolism. In this review, we describe new insights into mechanisms of CYP450 induction and inhibition. In addition, we provide a comprehensive review of the major interactions between ARVs recommended by WHO as firstor second-line therapy for HIV in resource-limited settings and drugs used to treat TB, malaria, and fungal, bacterial, and parasitic diseases.

Comparison of Once-Daily versus Twice-Daily Combination Antiretroviral Therapy in Treatment-Naive Patients: Results of AIDS Clinical Trials Group (ACTG) A5073, a 48-Week Randomized Controlled Trial

BACKGROUND Dosing frequency is an important determinant of regimen effectiveness. Methods. To compare efficacy of once-daily (QD) versus twice-daily (BID) antiretroviral therapy, we randomized human immunodeficiency virus (HIV)-positive, treatment-naive patients to lopinavir-ritonavir (LPV/r) administered at a dosage of 400 mg of lopinavir and 100 mg of ritonavir BID (n = 160) or 800 mg of lopinavir and 200 mg of ritonavir QD (n = 161), plus either emtricitabine 200 mg QD and extended-release stavudine at a dosage of 100 mg QD or tenofovir at a dosage of 300 mg QD. Randomization was stratified by screening HIV RNA level <100,000 copies/mL versus > or = 100,000 copies/mL. The primary efficacy end point was sustained virologic response (SVR; defined as reaching and maintaining an HIV RNA level <200 copies/mL) through week 48. RESULTS Subjects were 78% male, 33% Hispanic, and 34% black. A total of 82% of subjects completed the study, and 71% continued to receive the initially assigned dosage schedule. The probability of SVR did not differ significantly for the BID versus QD comparison, with an absolute proportional difference of 0.03 (95% confidence interval [CI], -0.07 to 0.12). The comparison depended on the screening RNA stratum (P=.038); in the higher RNA stratum, the probability of SVR was significantly better in the BID arm than in the QD arm: 0.89 (95% CI, 0.79-0.94) versus 0.76 (95% CI, 0.64-0.84), a difference of 0.13 (95% CI, 0.01-0.25). Lopinavir trough plasma concentrations were higher with BID dosing. Adherence to prescribed doses of LPV/r was 90.6% in the QD arm versus 79.9% in the BID arm (P<.001). Conclusions. Although subjects assigned to QD regimens had better adherence, overall treatment outcomes were similar in the QD and BID arms. Subjects with HIV RNA levels > or =100,000 copies/mL had better SVR with BID regimens at 48 weeks, which suggests a possible advantage in this setting for more frequent dosing. Clinical trial registration. ClinicalTrials.gov registration number: NCT00036452.

25-Hydroxyvitamin D Insufficiency and Deficiency is Associated With HIV Disease Progression and Virological Failure Post-Antiretroviral Therapy Initiation in Diverse Multinational Settings

BACKGROUND Low 25-hydroxyvitamin D (25(OH)D) has been associated with increased HIV mortality, but prospective studies assessing treatment outcomes after combination antiretroviral therapy (cART) initiation in resource-limited settings are lacking. METHODS A case-cohort study (N = 411) was nested within a randomized cART trial of 1571 cART-naive adults in 8 resource-limited settings and the United States. The primary outcome (WHO stage 3/4 disease or death within 96 weeks of cART initiation) was met by 192 cases, and 152 and 29 cases met secondary outcomes of virologic and immunologic failure. We studied prevalence and risk factors for baseline low 25(OH)D (<32 ng/mL) and examined associated outcomes using proportional hazard models. RESULTS Low 25(OH)D prevalence was 49% and ranged from 27% in Brazil to 78% in Thailand. Low 25(OH)D was associated with high body mass index (BMI), winter/spring season, country-race group, and lower viral load. Baseline low 25(OH)D was associated with increased risk of human immunodeficiency virus (HIV) progression and death (adjusted hazard ratio (aHR) 2.13; 95% confidence interval [CI], 1.09-4.18) and virologic failure (aHR 2.42; 95% CI, 1.33-4.41). CONCLUSIONS Low 25(OH)D is common in diverse HIV-infected populations and is an independent risk factor for clinical and virologic failure. Studies examining the potential benefit of vitamin D supplementation among HIV patients initiating cART are warranted.

CD4+ T Cell Depletion in an Untreated HIV Type 1-Infected Human Leukocyte Antigen-B*5801-Positive Patient with an Undetectable Viral Load

We report a case of a patient infected with human immunodeficiency virus type 1 (HIV-1) for 20 years who has experienced CD4(+) T cell depletion in spite of maintaining undetectable viral loads. Our data suggest that immune activation can cause CD4(+) T cell depletion even when HIV-1 replication appears to be controlled by host factors.

Pharmacokinetic and metabolic effects of American ginseng (Panax quinquefolius) in healthy volunteers receiving the HIV protease inhibitor indinavir

BackgroundComplementary and alternative medicine (CAM) use is prevalent among HIV-infected patients to reduce the toxicity of antiretroviral therapy. Ginseng has been used for treatment of hyperglycemia and insulin resistance, a common side effect of some HIV-1 protease inhibitors (PI). However, it is unknown whether American ginseng (AG) can reverse insulin resistance induced by the PI indinavir (IDV), and whether these two agents interact pharmacologically. We evaluated potential pharmacokinetic interactions between IDV and AG, and assessed whether AG improves IDV-induced insulin resistance.MethodsAfter baseline assessment of insulin sensitivity using the insulin clamp technique, healthy volunteers received IDV 800 mg q8 h for 3 days and then IDV and AG 1g q8h for 14 days. IDV pharmacokinetics and insulin sensitivity were assessed before and after AG co-administration.ResultsThere was no difference in the area-under the plasma-concentration-time curve after the co-administration of AG, compared to IDV alone (n = 13). Although insulin-stimulated glucose disposal per unit of insulin (M/I) decreased by an average of 14.8 ± 5.9% after 3 days of IDV (from 0.113 ± 0.012 to 0.096 ± 0.014 mg/kgFFM/min per μU/ml of insulin, p = 0.03, n = 11), M/I remained unchanged after co-administration of IDV and AG.ConclusionIDV decreases insulin sensitivity, which is unaltered by AG co-administration. AG does not significantly affect IDV pharmacokinetics.

Three Distinct Phases of HIV-1 RNA Decay in Treatment-Naive Patients Receiving Raltegravir-Based Antiretroviral Therapy: ACTG A5248

OBJECTIVE The goal of this study was to define viral kinetics after initiation of raltegravir (RAL)-based antiretroviral therapy (ART). METHODS ART-naive patients received RAL, tenofovir disoproxil fumarate, and emtricitabine for 72 weeks. Human immunodeficiency virus type 1 (HIV-1) RNA were measured by ultrasensitive and single-copy assays, and first (d1)-, second (d2)-, and, third (d3)-phase decay rates were estimated by mixed-effects models. Decay data were compared to historical estimates for efavirenz (EFV)- and ritonavir/lopinavir (LPV/r)-based regimens. RESULTS Bi- and tri-exponential models for ultrasensitive assay (n = 38) and single-copy assay (n = 8) data, respectively, provided the best fits over 8 and 72 weeks. The median d1 with ultrasensitive data was 0.563/day (interquartile range [IQR], 0.501-0.610/day), significantly slower than d1 for EFV-based regimens [P < .001]). The median duration of d1 was 15.1 days, transitioning to d2 at an HIV-1 RNA of 91 copies/mL, indicating a longer duration of d1 and a d2 transition at lower viremia levels than with EFV. Median patient-specific decay estimates with the single-copy assay were 0.607/day (IQR, 0.582-0.653) for d1, 0.070/day (IQR, 0.042-0.079) for d2, and 0.0016/day (IQR, 0.0005-0.0022) for d3; the median d1 duration was 16.1 days, transitioning to d2 at 69 copies/mL. d3 transition occurred at 110 days, at 2.6 copies/mL, similar to values for LPV/r-based regimens. CONCLUSIONS Models using single-copy assay data revealed 3 phases of decay with RAL-containing ART, with a longer duration of first-phase decay consistent with RAL-mediated blockade of productive infection from preintegration complexes.

Relationships among neurocognitive status, medication adherence measured by pharmacy refill records, and virologic suppression in HIV-infected persons

Background:Optimal antiretroviral therapy (ART) effectiveness depends on medication adherence, which is a complex behavior with many contributing factors, including neurocognitive function. Pharmacy refill records offer a promising and practical tool to assess adherence. Methods:A substudy of the CHARTER (CNS HIV Anti-Retroviral Therapy Effects Research) study was conducted at the Johns Hopkins University (JHU) and the University of Washington. Pharmacy refill records were the primary method to measure ART adherence, indexed to a “sentinel” drug with the highest central nervous system penetration–effectiveness score. Standardized neuromedical, neuropsychological, psychiatric, and substance use assessments were performed at enrollment and at 6 months. Regression models were used to determine factors associated with adherence and relationships between adherence and changes in plasma and cerebrospinal fluid HIV RNA concentrations between visits. Results:Among 80 (33 at JHU and 47 at University of Washington) participants, the mean adherence score was 86.4%, with no difference between sites. In the final multivariable model, better neurocognitive function was associated with better adherence, especially among participants who were at JHU, male, and HIV infected for a longer period of time. Worse performance in working memory tests was associated with worse adherence. Better adherence predicted greater decreases in cerebrospinal fluid HIV RNA between visits. Conclusions:Poorer global neurocognitive functioning and deficits in working memory were associated with lower adherence defined by a pharmacy refill record measure, suggesting that assessments of cognitive function, and working memory in particular, may identify patients at risk for poor ART adherence who would benefit from adherence support.

Dynamics of Immune Reconstitution and Activation Markers in HIV+ Treatment-Naïve Patients Treated with Raltegravir, Tenofovir Disoproxil Fumarate and Emtricitabine

Background The dynamics of CD4+ T cell reconstitution and changes in immune activation and inflammation in HIV-1 disease following initiation of antiretroviral therapy (ART) are incompletely defined and their underlying mechanisms poorly understood. Methods Thirty-nine treatment-naïve patients were treated with raltegravir, tenofovir DF and emtricitabine. Immunologic and inflammatory indices were examined in persons with sustained virologic control during 48 weeks of therapy. Results Initiation of ART increased CD4+ T cell numbers and decreased activation and cell cycle entry among CD4+ and CD8+ T cell subsets, and attenuated markers of coagulation (D-dimer levels) and inflammation (IL-6 and TNFr1). These indices decayed at different rates and almost all remained elevated above levels measured in HIV-seronegatives through 48 weeks of viral control. Greater first and second phase CD4+ T cell restoration was related to lower T cell activation and cell cycling at baseline, to their decay with treatment, and to baseline levels of selected inflammatory indices, but less so to their changes on therapy. Conclusions ART initiation results in dynamic changes in viral replication, T cell restoration, and indices of immune activation, inflammation, and coagulation. These findings suggest that determinants of T cell activation/cycling and inflammation/coagulation may have distinguishable impact on immune homeostasis. Trial Registration Clinicaltrials.gov NCT00660972