The anti-HIV drug abacavir stimulates β-catenin activity in osteoblast lineage cells

Bone mineral density (BMD) loss in people living with HIV occurs with the initiation of combined antiretroviral therapy (cART), particularly with tenofovir disoproxil fumarate (TDF) containing cART. Switching from TDF to abacavir (ABC) or dolutegravir (DTG) leads to increased BMD. Whether BMD gains are due to cessation of TDF or anabolic effects of ABC or DTG is unclear. We investigated the effects of ABC and DTG on osteoblast lineage cells in vitro and in vivo. Primary human osteoblasts and male C57BL/6 mice were treated with individual antiretrovirals (ARVs) or a combination of ABC/DTG/lamivudine (3TC). Nearly all ARVs and cART inhibited osteogenic activity in vitro. Due to the importance of Wnt/β-catenin in bone formation, we further investigated ARV effects on the Wnt/β-catenin pathway. ABC, alone and as part of ABC/DTG/3TC, increased osteoblastic β-catenin activity as indicated by increased TOPFlash activity, hypo-phosphorylated (active) β-catenin staining, and β-catenin targeted gene expression. Mice treated with TDF had decreased lumbar spine BMD and trabecular connectivity density in the vertebrae, while those treated with ABC/DTG/3TC reduced cortical area and thickness in the femur. Mice treated with ABC alone had no bone structural changes, increased circulating levels of the bone formation marker, P1NP, and elevated expression of the Wnt/β-catenin target gene, Lef1, in osteocyte enriched samples. Further, bones from ARV-treated mice were isolated to evaluate ARV distribution. All ARVs were detected in the bone tissue, which was inclusive of bone marrow, but when bone marrow was removed, only TDF, ABC, and DTG were detected at ~0.1% of the circulating levels. Overall, our findings demonstrate that ABC activates Wnt/β-catenin signaling, but whether this leads to increased bone formation requires further study. Assessing the impact of ARVs on bone is critical to informing ARV selection and/or discovery of regimens that do not negatively impact the skeleton.

Twice-Daily Dolutegravir Based Antiretroviral Therapy with One Month of Daily Rifapentine and Isoniazid (1HP) for TB Prevention

BACKGROUND

One month of daily rifapentine + isoniazid (1HP) is an effective, ultrashort option for TB prevention in people with HIV (PWH). However, rifapentine may decrease antiretroviral drug concentrations and increase the risk of virologic failure. ACTG A5372 evaluated the effect of 1HP on the pharmacokinetics of twice daily dolutegravir.

METHODS

A5372 was a multicenter, pharmacokinetic study in PWH (≥18 years) already on dolutegravir-containing antiretroviral therapy with HIV RNA < 50 copies/mL. Participants received daily rifapentine/isoniazid (600mg/300mg) for 28 days as part of 1HP. Dolutegravir was increased to 50mg twice daily during 1HP and intensive pharmacokinetic sampling was performed on day 0 (before 1HP) and on the final day of 1HP treatment.

RESULTS

Thirty-two participants (41% female; 66% Black/African; median (Q1, Q3) age 42 (34, 49) years) were included in the pharmacokinetic analysis. Thirty-one of 32 had HIV RNA levels <50 copies/mL at the end of 1HP dosing. One participant had an HIV RNA of 160 copies/mL at day 28, with HIV RNA <50 copies/mL upon repeat testing on day 42. The median (Q1, Q3) dolutegravir trough concentration was 1751 ng/mL (1195, 2542) on day 0 vs. 1987ng/mL (1331, 2278) on day 28 (day 28:day 0 GMR 1.05, [90% CI 0.93-1.2]; p = 0.43). No serious adverse events were reported.

CONCLUSION

Dolutegravir trough concentrations with 50mg twice daily dosing during 1HP treatment were greater than those with standard dose dolutegravir once daily without 1HP. These pharmacokinetic, virologic, and safety data provide support for twice daily dolutegravir use in combination with 1HP for TB prevention.

Chemotherapy in pediatric brain tumor and the challenge of the blood-brain barrier

BACKGROUND

Pediatric brain tumors (PBT) stand as the leading cause of cancer-related deaths in children. Chemoradiation protocols have improved survival rates, even for non-resectable tumors. Nonetheless, radiation therapy carries the risk of numerous adverse effects that can have long-lasting, detrimental effects on the quality of life for survivors. The pursuit of chemotherapeutics that could obviate the need for radiotherapy remains ongoing. Several anti-tumor agents, including sunitinib, valproic acid, carboplatin, and panobinostat, have shown effectiveness in various malignancies but have not proven effective in treating PBT. The presence of the blood-brain barrier (BBB) plays a pivotal role in maintaining suboptimal concentrations of anti-cancer drugs in the central nervous system (CNS). Ongoing research aims to modulate the integrity of the BBB to attain clinically effective drug concentrations in the CNS. However, current findings on the interaction of exogenous chemical agents with the BBB remain limited and do not provide a comprehensive explanation for the ineffectiveness of established anti-cancer drugs in PBT.

METHODS

We conducted our search for chemotherapeutic agents associated with the blood-brain barrier (BBB) using the following keywords: Chemotherapy in Cancer, Chemotherapy in Brain Cancer, Chemotherapy in PBT, BBB Inhibition of Drugs into CNS, Suboptimal Concentration of CNS Drugs, PBT Drugs and BBB, and Potential PBT Drugs. We reviewed each relevant article before compiling the information in our manuscript. For the generation of figures, we utilized BioRender software.

FOCUS

We focused our article search on chemical agents for PBT and subsequently investigated the role of the BBB in this context. Our search criteria included clinical trials, both randomized and non-randomized studies, preclinical research, review articles, and research papers.

FINDING

Our research suggests that, despite the availability of potent chemotherapeutic agents for several types of cancer, the effectiveness of these chemical agents in treating PBT has not been comprehensively explored. Additionally, there is a scarcity of studies examining the role of the BBB in the suboptimal outcomes of PBT treatment, despite the effectiveness of these drugs for other types of tumors.

Pharmacogenetic interactions of efavirenz or rifampin and isoniazid with levonorgestrel emergency contraception during treatment of HIV or tuberculosis

OBJECTIVE

In AIDS Clinical Trials Group study A5375, a pharmacokinetic trial of levonorgestrel emergency contraception, double-dose levonorgestrel (3 mg, versus standard dose 1.5 mg) offset the induction effects of efavirenz or rifampin on plasma levonorgestrel exposure over 8 h post-dose (AUC 0-8h ). We characterized the pharmacogenetics of these interactions.

METHODS

Cisgender women receiving efavirenz- or dolutegravir-based HIV therapy, or on isoniazid-rifampin for tuberculosis, were followed after a single oral dose of levonorgestrel. Linear regression models, adjusted for BMI and age, characterized associations of CYP2B6 and NAT2 genotypes (which affect plasma efavirenz and isoniazid exposure, respectively) with levonorgestrel pharmacokinetic parameters.

RESULTS

Of 118 evaluable participants, 17 received efavirenz/levonorgestrel 1.5 mg, 35 efavirenz/levonorgestrel 3 mg, 34 isoniazid-rifampin/levonorgestrel 3 mg, and 32 (control group) dolutegravir/levonorgestrel 1.5 mg. There were 73 Black and 33 Asian participants. Regardless of genotype, women on efavirenz and isoniazid-rifampin had higher levonorgestrel clearance. In the efavirenz/levonorgestrel 3 mg group, CYP2B6 normal/intermediate metabolizers had levonorgestrel AUC 0-8h values similar to controls, while CYP2B6 poor metabolizers had AUC 0-8h values of 40% lower than controls. In the isoniazid-rifampin group, NAT2 rapid/intermediate acetylators had levonorgestrel AUC 0-8h values similar to controls, while NAT2 slow acetylators had AUC 0-8h values 36% higher than controls.

CONCLUSION

CYP2B6 poor metabolizer genotypes exacerbate the efavirenz-levonorgestrel interaction, likely by increased CYP3A induction with higher efavirenz exposure, making the interaction more difficult to overcome. NAT2 slow acetylator genotypes attenuate the rifampin-levonorgestrel interaction, likely by increased CYP3A inhibition with higher isoniazid exposure.

Quantification of nine antiretroviral drugs in cerebrospinal fluid: An approach to overcome sample collection tube adsorption

A highly sensitive LC-MS/MS methods were developed and validated to quantify nine antiretrovirals (atazanavir [ATV], tenofovir [TFV], emtricitabine [FTC], darunavir [DRV], dolutegravir [DTG], efavirenz [EFV], lamivudine [3TC], raltegravir [RAL], and ritonavir [RTV]) in human cerebral spinal fluid (CSF). The approach remedies adsorption issues caused by polypropylene based sample collection tubes. 1% ammonium hydroxide in methanol was added in an amount equal to the volume of each quality control (QC) or patient sample. Protein precipitation was utilized with a CSF sample volume of 100 μL and a 100 μL of methanol:ACN and vortexed. Chromatographic separation was achieved with a 3 × 100 ACE® C18 column for ATV, DRV, DTG, EFV, RTV and RAL, and a 2 × 100 Polar RP column for TFV/FTC/3TC. Mobile phase was methanol:water:formic acid (70:30:0.1, v/v/v) for ATV, DRV, DTG, EFV and RTV (10 uL injection, flow rate: 1.00 mL/min), ACN:water:formic acid (35:65:0.1, v/v/v) for RAL (50 uL injection, flow rate: 1.00 mL/min), ACN:water:formic acid (2:98:0.1, v/v/v) for TFV, FTC and 3TC (50 uL injection, flow rate: 0.35 mL/min). Column temperature was 40° C across all assays. The mass spectrometer was operated in positive, multiple-reaction-monitoring (MRM) mode with electrospray ionization (ESI) for all analytes with the exception of EFV, which was operated in negative, MRM mode with ESI. The assay was linear over the calibration range of 1 to 250 ng/mL for all analytes. The addition of 1% ammonium hydroxide in sample tubes overcame up to 44% negative bias in QC samples and allowed the methods to meet full validation criteria.

ACE-2, TMPRSS2, and Neuropilin-1 Receptor Expression on Human Brain Astrocytes and Pericytes and SARS-CoV-2 Infection Kinetics

Angiotensin Converting Enzyme 2 (ACE-2), Transmembrane Serine Protease 2 (TMPRSS-2) and Neuropilin-1 cellular receptors support the entry of SARS-CoV-2 into susceptible human target cells and are characterized at the molecular level. Some evidence on the expression of entry receptors at mRNA and protein levels in brain cells is available, but co-expression of these receptors and confirmatory evidence on brain cells is lacking. SARS-CoV-2 infects some brain cell types, but infection susceptibility, multiple entry receptor density, and infection kinetics are rarely reported in specific brain cell types. Highly sensitive Taqman ddPCR, flow-cytometry and immunocytochemistry assays were used to quantitate the expression of ACE-2, TMPRSS-2 and Neuropilin-1 at mRNA and protein levels on human brain-extracted pericytes and astrocytes, which are an integral part of the Blood-Brain-Barrier (BBB). Astrocytes showed moderate ACE-2 (15.9 ± 1.3%, Mean ± SD, n = 2) and TMPRSS-2 (17.6%) positive cells, and in contrast show high Neuropilin-1 (56.4 ± 39.8%, n = 4) protein expression. Whereas pericytes showed variable ACE-2 (23.1 ± 20.7%, n = 2), Neuropilin-1 (30.3 ± 7.5%, n = 4) protein expression and higher TMPRSS-2 mRNA (667.2 ± 232.3, n = 3) expression. Co-expression of multiple entry receptors on astrocytes and pericytes allows entry of SARS-CoV-2 and progression of infection. Astrocytes showed roughly four-fold more virus in culture supernatants than pericytes. SARS-CoV-2 cellular entry receptor expression and "in vitro" viral kinetics in astrocytes and pericytes may improve our understanding of viral infection "in vivo". In addition, this study may facilitate the development of novel strategies to counter the effects of SARS-CoV-2 and inhibit viral infection in brain tissues to prevent the spread and interference in neuronal functions.

Pharmacokinetics of dose-adjusted levonorgestrel emergency contraception combined with efavirenz-based antiretroviral therapy or rifampicin-containing tuberculosis regimens

OBJECTIVES

To determine if double-dose levonorgestrel emergency contraception (EC) in combination with efavirenz or rifampicin, 2 drugs known to decrease levonorgestrel exposure, resulted in similar pharmacokinetics compared to standard-dose levonorgestrel EC without drug-drug interactions.

STUDY DESIGN

We conducted a phase 2, open-label, multicenter, partially randomized, 4 parallel group trial in pre-menopausal females ≥16 years old without an indication for EC and not on hormonal contraception. Participants on dolutegravir-based antiretroviral therapy (ART) received levonorgestrel 1.5 mg (control group); those on rifampicin-containing tuberculosis therapy received levonorgestrel 3 mg; those on efavirenz-based ART were randomized 1:2 to levonorgestrel 1.5 mg or 3 mg. Plasma was collected through 48 hours post-dose to assess levonorgestrel pharmacokinetics. Area under the concentration-time curve (AUC) over 8 hours was the primary outcome. Levonorgestrel pharmacokinetic parameters were compared between groups using geometric mean ratios (GMR) with 90% confidence intervals.

RESULTS

The median (Q1, Q3) age for all participants (n = 118) was 34 (27, 41) years and BMI was 23.2 (20, 26.3) kg/m2. Participants receiving levonorgestrel 1.5mg plus efavirenz (n = 17) had 50% lower AUC0-8h compared to the control group (n = 32) [0.50 (0.40, 0.62)]. Participants receiving levonorgestrel 3 mg had a similar AUC0-8h when receiving either efavirenz (n = 35) [0.99 (0.81, 1.20)] or rifampicin (n = 34) [1.16 (0.99, 1.36)] compared to control. Levonorgestrel 3 mg resulted in similar or higher maximum concentration with either efavirenz [1.17 (0.96, 1.41)] or rifampicin [1.27 (1.09, 1.49)] compared to the control group.

CONCLUSIONS

Doubling the dose of levonorgestrel EC successfully increased levonorgestrel exposure over the first 8 hours in participants receiving either efavirenz-based ART or rifampicin-containing tuberculosis therapy.

IMPLICATIONS

Adjusting levonorgestrel emergency contraception from 1.5 mg to 3 mg improves levonorgestrel pharmacokinetic exposure in participants receiving either efavirenz-based antiretroviral regimens or rifampicin-containing tuberculosis therapy. These data support guideline recommendations to double the dose of levonorgestrel emergency contraception in persons on medications that decrease levonorgestrel exposure by inducing levonorgestrel metabolism.

A novel 4-cell in-vitro blood-brain barrier model and its characterization by confocal microscopy and TEER measurement

The blood-brain barrier (BBB) is a protective cellular anatomical layer with a dynamic micro-environment, tightly regulating the transport of materials across it. To achieve in-vivo characteristics, an in-vitro BBB model requires the constituent cell types to be layered in an appropriate order. A cost-effective in-vitro BBB model is desired to facilitate central nervous system (CNS) drug penetration studies. Enhanced integrity of tight junctions observed during the in-vitro BBB establishment and post-experiment is essential in these models. We successfully developed an in-vitro BBB model mimicking the in-vivo cell composition and a distinct order of seeding primary human brain cells. Unlike other in-vitro BBB models, our work avoids the need for pre-coated plates for cell adhesion and provides better cell visualization during the procedure. We found that using bovine collagen-I coating, followed by bovine fibronectin coating and poly-L-lysine coating, yields better adhesion and layering of cells on the transwell membrane compared to earlier reported use of collagen and poly-L-lysine only. Our results indicated better cell visibility and imaging with the polyester transwell membrane as well as point to a higher and more stable Trans Endothelial Electrical Resistance values in this plate. In addition, we found that the addition of zinc induced higher claudin 5 expressions in neuronal cells. Dolutegravir, a drug used in the treatment of HIV, is known to appear in moderate concentrations in the CNS. Thus, dolutegravir was used to assess the functionality of the final model and cells. Using primary cells and an in-house coating strategy substantially reduces costs and provides superior imaging of cells and their tight junction protein expression. Our 4-cell-based BBB model is a suitable experimental model for the drug screening process.

An Efficient Humanized Mouse Model for Oral Anti-Retroviral Administration

HIV anti-retrovirals (ARVs) have vastly improved the life expectancy of people living with HIV (PLWH). However, toxic effects attributed to long-term ARV use also contribute to HIV-related co-morbidities such as heart disease, bone loss and HIV-associated neurocognitive disorders (HAND). Unfortunately, mouse models used to study the effects of ARVs on viral suppression, toxicity and HIV latency/tissue reservoirs have not been widely established. Here, we demonstrate an effective mouse model utilizing immune-compromised mice, reconstituted with infected human peripheral blood mononuclear cell (PBMCs). ARV is incorporated into mouse chow and administered daily. Combination ARV regimens included Atripla (efavirenz, tenofovir disoproxil fumarate, and emtricitabine) and Triumeq (abacavir, dolutegravir and lamivudine). Our model measures HIV-infected human cell trafficking, and ARV penetration throughout most relevant HIV organs and plasma, with a large amount of trafficking to the secondary lymphoid organs. Furthermore, te HIV viral load within each organ and the plasma was reduced in ARVs treated vs. untreated control. Overall, we have demonstrated a mouse model that is relatively easy and affordable to establish and utilize to study ARVs’ effect on various tissues, including the co-morbid conditions associated with PLWH, such as HAND, and other toxic effects.

Effectiveness and Safety of Bictegravir/Emtricitabine/Tenofovir Alafenamide in Patients With HIV-1 Infection and Ongoing Substance Use Disorder: The BASE Study

Background

People with human immunodeficiency virus (HIV) and substance use disorder (PWH/SUD) are at higher risk of nonadherence to antiretroviral therapy. Bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) exhibits high rates of efficacy with a favorable adverse event profile. The BASE study (NCT03998176) is a phase 4, single-arm study evaluating the effectiveness and safety of B/F/TAF among PWH/SUD.

Methods

Viremic (HIV RNA >1000 copies/mL) PWH/SUD initiated B/F/TAF once daily for 48 weeks (W). The primary endpoint was proportion of participants with HIV RNA <50 copies/mL at W24. Secondary endpoints were proportion of participants with HIV-1 RNA <50 copies/mL at W48, safety, B/F/TAF adherence (dried blood spot [DBS] concentrations of emtricitabine triphosphate and tenofovir diphosphate [TFV-DP]), substance use (NIDA-ASSIST), and quality of life (SF-12).

Results

Forty-three participants were enrolled; 95% reported methamphetamine use. Median age was 38 (range, 21-62) years; 21% were female, 81% White, 14% Black, and 16% Hispanic. Thirty-two (74%) and 21 (49%) participants had HIV RNA <50 copies/mL (intention-to-treat) at W24 and W48, respectively. Seven participants (16%) experienced confirmed virologic failure through W48; 1 developed emergent drug resistance (M184V). Fifteen participants (35%) experienced grade ≥3 adverse events. Five participants (12%) reported suicidal ideation; none resulted in discontinuation. Median DBS concentrations were representative of 5-6 doses/week (TFV-DP, 1603 fmol/punches). NIDA-ASSIST scores declined from baseline to W48 with methamphetamine use decreasing most (-7.9 points; -29%), and SF-12 physical/mental scores increased 1.2 and 7.6 points, respectively.

Conclusions

B/F/TAF among a high-risk population of PWH/SUD resulted in an initial 72% viral suppression rate at W24 before dropping to 49% at W48 as retention declined. One participant developed emergent drug resistance (M184V).

Rifapentine With and Without Moxifloxacin for Pulmonary Tuberculosis in People With Human Immunodeficiency Virus (S31/A5349)

BACKGROUND

Tuberculosis (TB) Trials Consortium Study 31/AIDS Clinical Trials Group A5349, an international randomized open-label phase 3 noninferiority trial showed that a 4-month daily regimen substituting rifapentine for rifampin and moxifloxacin for ethambutol had noninferior efficacy and was safe for the treatment of drug-susceptible pulmonary TB (DS-PTB) compared with the standard 6-month regimen. We explored results among the prespecified subgroup of people with human immunodeficiency virus (HIV) (PWH).

METHODS

PWH and CD4+ counts ≥100 cells/μL were eligible if they were receiving or about to initiate efavirenz-based antiretroviral therapy (ART). Primary endpoints of TB disease-free survival 12 months after randomization (efficacy) and ≥ grade 3 adverse events (AEs) on treatment (safety) were compared, using a 6.6% noninferiority margin for efficacy. Randomization was stratified by site, pulmonary cavitation, and HIV status. PWH were enrolled in a staged fashion to support cautious evaluation of drug-drug interactions between rifapentine and efavirenz.

RESULTS

A total of 2516 participants from 13 countries in sub-Saharan Africa, Asia, and the Americas were enrolled. Among 194 (8%) microbiologically eligible PWH, the median CD4+ count was 344 cells/μL (interquartile range: 223-455). The rifapentine-moxifloxacin regimen was noninferior to control (absolute difference in unfavorable outcomes -7.4%; 95% confidence interval [CI] -20.8% to 6.0%); the rifapentine regimen was not noninferior to control (+7.5% [95% CI, -7.3% to +22.4%]). Fewer AEs were reported in rifapentine-based regimens (15%) than the control regimen (21%).

CONCLUSIONS

In people with HIV-associated DS-PTB with CD4+ counts ≥100 cells/μL on efavirenz-based ART, the 4-month daily rifapentine-moxifloxacin regimen was noninferior to the 6-month control regimen and was safe.

CLINICAL TRIALS REGISTRATION

NCT02410772.

Population Pharmacokinetic Modeling and Simulation of Rifapentine Supports Concomitant Antiretroviral Therapy with Efavirenz and Non-Weight Based Dosing

The Brief Rifapentine-Isoniazid Efficacy for TB Prevention/A5279 trial demonstrated a 1-month daily regimen of rifapentine and isoniazid was noninferior to 9 months of isoniazid alone for preventing TB in persons living with HIV (PLWH). Our objective was to evaluate rifapentine pharmacokinetics in trial participants receiving antiretroviral therapy (ART) and perform simulations to compare weight-based rifapentine dosing with a standard, fixed dose. Nonlinear mixed effect modeling was used to estimate rifapentine and 25-desacetyl rifapentine population pharmacokinetic characteristics. The pharmacokinetic model was validated using a nonparametric bootstrap and visual predictive checks. Monte Carlo simulations were performed to compare weight-based and fixed dose regimens. Rifapentine and 25-desacetyl rifapentine concentrations (347 of each; 185 participants) were each described with a one-compartment model with one-way conversion between rifapentine and 25-desacetyl rifapentine. The absorption rate was nearly doubled in fed versus fasting states. Rifapentine clearance was increased 31% in those receiving efavirenz (EFV)-based versus nevirapine-based ART. Metabolite clearance was allometrically scaled with fat-free mass. Simulations showed lower rifapentine exposures with weight-based compared with fixed dosing. With 10 mg/kg weight-based regimens, 26% and 62% of simulated exposures in <35 kg and 35-45 kg weight classes were above target (AUC0 to 24 h of 257 mg*hr/L); 85% of simulated exposures across all weight classes with fixed dosing were above target. These data support fixed dosing with rifapentine 600 mg daily for TB prevention regardless of weight for PLWH 13 years or older receiving the 4-week regimen and no need for dose adjustment when given with EFV-based ART. Clinical Trials Registration. NCT01404312.

Efavirenz Pharmacokinetics and Human Immunodeficiency Virus Type 1 (HIV-1) Viral Suppression Among Patients Receiving Tuberculosis Treatment Containing Daily High-Dose Rifapentine

BACKGROUND

A 4-month regimen containing rifapentine and moxifloxacin has noninferior efficacy compared to the standard 6-month regimen for drug-sensitive tuberculosis. We evaluated the effect of regimens containing daily, high-dose rifapentine on efavirenz pharmacokinetics and viral suppression in patients with human immunodeficiency virus (HIV)-associated tuberculosis (TB).

METHODS

In the context of a Phase 3 randomized controlled trial, HIV-positive individuals already virally suppressed on efavirenz--containing antiretroviral therapy (ART) (EFV1), or newly initiating efavirenz (EFV2) received TB treatment containing rifapentine (1200 mg), isoniazid, pyrazinamide, and either ethambutol or moxifloxacin. Mid-interval efavirenz concentrations were measured (a) during ART and TB cotreatment (Weeks 4, 8, 12, and 17, different by EFV group) and (b) when ART was taken alone (pre- or post-TB treatment, Weeks 0 and 22). Apparent oral clearance (CL/F) was estimated and compared. Target mid-interval efavirenz concentrations were > 1 mg/L. Co-treatment was considered acceptable if > 80% of participants had mid-interval efavirenz concentrations meeting this target.

RESULTS

EFV1 and EFV2 included 70 and 41 evaluable participants, respectively. The geometric mean ratio comparing efavirenz CL/F with vs without TB drugs was 0.79 (90% confidence interval [CI] .72-.85) in EFV1 and 0.84 [90% CI .69-.97] in EFV2. The percent of participants with mid-interval efavirenz concentrations > 1mg/L in EFV1 at Weeks 0, 4, 8, and 17 was 96%, 96%, 88%, and 89%, respectively. In EFV2, at approximately 4 and 8 weeks post efavirenz initiation, the value was 98%.

CONCLUSIONS

TB treatment containing high-dose daily rifapentine modestly decreased (rather than increased) efavirenz clearance and therapeutic targets were met supporting the use of efavirenz with these regimens, without dose adjustment.

CLINICAL TRIALS REGISTRATION

NCT02410772.

Transformation of dolutegravir into an ultra-long-acting parenteral prodrug formulation

Ultra-long-acting integrase strand transfer inhibitors were created by screening a library of monomeric and dimeric dolutegravir (DTG) prodrug nanoformulations. This led to an 18-carbon chain modified ester prodrug nanocrystal (coined NM2DTG) with the potential to sustain yearly dosing. Here, we show that the physiochemical and pharmacokinetic (PK) formulation properties facilitate slow drug release from tissue macrophage depot stores at the muscle injection site and adjacent lymphoid tissues following single parenteral injection. Significant plasma drug levels are recorded up to a year following injection. Tissue sites for prodrug hydrolysis are dependent on nanocrystal dissolution and prodrug release, drug-depot volume, perfusion, and cell-tissue pH. Each affect an extended NM2DTG apparent half-life recorded by PK parameters. The NM2DTG product can impact therapeutic adherence, tolerability, and access of a widely used integrase inhibitor in both resource limited and rich settings to reduce HIV-1 transmission and achieve optimal treatment outcomes.

Factors associated with viral suppression among cisgender women living with human immunodeficiency virus in the United States: An integrative review

INTRODUCTION

Women account for 23% of new human immunodeficiency virus diagnoses in the United States, yet remain understudied. Adherence to antiretroviral therapy and consequent viral suppression are keys to preventing human immunodeficiency virus transmission, reducing risk of drug resistance, and improving health outcomes.

OBJECTIVES

This review identified and synthesized peer-reviewed studies in the United States describing factors associated with viral suppression among cisgender women living with human immunodeficiency virus.

METHODS

We searched five databases: Cumulative Index to Nursing and Allied Health (CINAHL), PubMed, Embase, Scopus, and PsycINFO, and reported the findings using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Eligible studies included: (1) peer-reviewed English-language articles published since 2010; (2) includes only cisgender women; (3) participants were at least 18 years of age; (4) reported metrics on viral loads; and (5) conducted in the United States.

RESULTS

Fourteen studies in total were reviewed. Eight studies had adult women living with human immunodeficiency virus, four recruited only pregnant women, and two included only racial minority women. The most commonly reported factors negatively associated with viral suppression were substance use (n = 4), followed by availability of health insurance, financial constraint, complexity of human immunodeficiency virus treatment regimen (n = 3), and intimate partner violence (n = 2). Other factors were depression, race, and age. In addition, all four studies that included only pregnant women reported early human immunodeficiency virus care engagement as a significant predictor of low viral loads pre- and post-partum.

CONCLUSION

Substance use, financial constraint, lack of health insurance, human immunodeficiency virus treatment regimen type, intimate partner violence, and late human immunodeficiency virus care pre-post pregnancy were the most common factors negatively associated with viral suppression. There is a paucity of data on viral suppression factors related to transgender and rural populations. More human immunodeficiency virus research is needed to explore factors associated with human immunodeficiency virus treatment outcomes in transgender women and cisgender women in rural U.S. regions.

Diminished Peripheral CD29hi Cytotoxic CD4+ T Cells Are Associated With Deleterious Effects During SIV Infection

Cytotoxic CD4+ T cells (CD4+ CTLs) limit HIV pathogenesis, as evidenced in elite controllers (a subset of individuals who suppress the virus without the need for therapy). CD4+ CTLs have also been shown to kill HIV-infected macrophages. However, little is known about their contribution towards HIV persistence, how they are affected following exposure to immune modulators like morphine, and what factors maintain their frequencies and function. Further, the lack of robust markers to identify CD4+ CTLs in various animal models limits understanding of their role in HIV pathogenesis. We utilized various PBMC samples obtained from SIV infected and cART treated rhesus macaques exposed to morphine or saline and subjected to flow cytometry evaluations. Thereafter, we compared and correlated the expression of CD4+ CTL-specific markers to viral load and viral reservoir estimations in total CD4+ T cells. We found that CD29 could be reliably used as a marker to identify CD4+ CTLs in rhesus macaques since CD29hi CD4+ T cells secrete higher cytotoxic and proinflammatory cytokines following PMA/ionomycin or gag stimulation. In addition, this immune cell subset was depleted during untreated SIV infection. Strikingly, we also observed that early initiation of cART reconstitutes depleted CD29hi CD4+ T cells and restores their function. Furthermore, we noted that morphine exposure reduced the secretion of proinflammatory cytokines/cytotoxic molecules in CD29hi CD4+ T cells. Lastly, increased functionality of CD29hi CD4+ T cells as depicted by elevated levels of either IL-21 or granzyme B hi T Bet+ gag specific responses were linked to limiting the size of the replication-competent reservoir during cART treatment. Collectively, our data suggest that CD4+ CTLs are crucial in limiting SIV pathogenesis and persistence.

Comparative Clinical Pharmacokinetics and Pharmacodynamics of HIV-1 Integrase Strand Transfer Inhibitors: An Updated Review

Bictegravir, cabotegravir, dolutegravir, elvitegravir, and raltegravir are members of the latest class of antiretrovirals available to treat human immunodeficiency virus (HIV) infection, the integrase strand transfer inhibitors. Integrase strand transfer inhibitors are potent inhibitors of the HIV integrase enzyme with IC_90/95 values in the low nanogram per milliliter range and they retain antiviral activity against strains of HIV with acquired resistance to other classes of antiretrovirals. Each of the integrase strand transfer inhibitors have unique pharmacokinetic/pharmacodynamic properties, influencing their role in clinical use in specific subsets of patients. Cabotegravir, approved for use in Canada but not yet by the US Food and Drug Administration, is formulated in both oral and intramuscular formulations; the latter of which has shown efficacy as a long-acting extended-release formulation. Cabotegravir, raltegravir, and dolutegravir have minimal drug-drug interaction profiles, as their metabolism has minimal cytochrome P450 involvement. Conversely, elvitegravir metabolism occurs primarily via cytochrome P450 3A4 and requires pharmacokinetic boosting to achieve systemic exposures amenable to once-daily dosing. Bictegravir metabolism has similar contributions from both cytochrome P450 3A4 and uridine 5'-diphospho-glucuronosyltransferase 1A1. Bictegravir, dolutegravir, and raltegravir are recommended components of initial regimens for most people with HIV in the US adult and adolescent HIV treatment guidelines. This review summarizes and compares the pharmacokinetics and pharmacodynamics of the integrase strand transfer inhibitor agents, and describes specific pharmacokinetic considerations for persons with hepatic impairment, renal dysfunction, pregnancy, and co-infections.

Safety and Pharmacokinetics of Double-Dose Lopinavir/Ritonavir + Rifampin Versus Lopinavir/Ritonavir + Daily Rifabutin for Treatment of Human Immunodeficiency Virus-Tuberculosis Coinfection

BACKGROUND

Protease inhibitor-based antiretroviral therapy may be used in resource-limited settings in persons with human immunodeficiency virus and tuberculosis (HIV-TB). Data on safety, pharmacokinetics/pharmacodynamics (PK/PD), and HIV-TB outcomes for lopinavir/ritonavir (LPV/r) used with rifampin (RIF) or rifabutin (RBT) are limited.

METHODS

We randomized adults with HIV-TB from July 2013 to February 2016 to arm A, LPV/r 400 mg/100 mg twice daily + RBT 150 mg/day; arm B, LPV/r 800 mg/200 mg twice daily + RIF 600 mg/day; or arm C, LPV/r 400 mg/100 mg twice daily + raltegravir (RAL) 400 mg twice daily + RBT 150 mg/day. All received two nucleoside reverse transcriptase inhibitors and other TB drugs. PK visits occurred on day 12 ± 2. Within-arm HIV-TB outcomes were summarized using proportions and 95% CIs; PK were compared using Wilcoxon tests.

RESULTS

Among 71 participants, 52% were women; 72% Black; 46% Hispanic; median age, 37 years; median CD4+ count, 130 cells/mm3; median HIV-1 RNA, 4.6 log10 copies/mL; 46% had confirmed TB. LPV concentrations were similar across arms. Pooled LPV AUC12 (157 203 hours × ng/mL) and Ctrough (9876 ng/mL) were similar to historical controls; RBT AUC24 (7374 hours × ng/mL) and Ctrough (208 ng/mL) were higher, although 3 participants in arm C had RBT Cmax <250 ng/mL. Proportions with week 48 HIV-1 RNA <400 copies/mL were 58%, 67%, and 61%, respectively, in arms A, B, and C.

CONCLUSIONS

Double-dose LPV/r+RIF and LPV/r+RBT 150mg/day had acceptable safety, PK and TB outcomes; HIV suppression was suboptimal but unrelated to PK. Faster RBT clearance and low Cmax in 3 participants on RBT+RAL requires further study.

Therapeutic implications of SARS-CoV-2 dysregulation of the gut-brain-lung axis

The emergence and rapid spread of novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused over 180 million confirmed cases resulting in over 4 million deaths worldwide with no clear end in sight for the coronavirus disease 19 (COVID-19) pandemic. Most SARS-CoV-2 exposed individuals experience mild to moderate symptoms, including fever, cough, fatigue, and loss of smell and taste. However, many individuals develop pneumonia, acute respiratory distress syndrome, septic shock, and multiorgan dysfunction. In addition to these primarily respiratory symptoms, SARS-CoV-2 can also infiltrate the central nervous system, which may damage the blood-brain barrier and the neuron's synapses. Resultant inflammation and neurodegeneration in the brain stem can further prevent efferent signaling to cranial nerves, leading to the loss of anti-inflammatory signaling and normal respiratory and gastrointestinal functions. Additionally, SARS-CoV-2 can infect enterocytes resulting in gut damage followed by microbial dysbiosis and translocation of bacteria and their byproducts across the damaged epithelial barrier. As a result, this exacerbates pro-inflammatory responses both locally and systemically, resulting in impaired clinical outcomes. Recent evidence has highlighted the complex interactions that mutually modulate respiratory, neurological, and gastrointestinal function. In this review, we discuss the ways SARS-CoV-2 potentially disrupts the gut-brain-lung axis. We further highlight targeting specific responses to SARS-CoV-2 for the development of novel, urgently needed therapeutic interventions. Finally, we propose a prospective related to the individuals from Low- and Middle-Income countries. Here, the underlying propensity for heightened gut damage/microbial translocation is likely to result in worse clinical outcomes during this COVID-19 pandemic.

Intramuscular and subcutaneous administration of antiretroviral drugs, compared with oral, enhances delivery to lymphoid tissues in BALB/c mice

BACKGROUND

Multiple tissue reservoirs are established soon after HIV infection, and some tissues may also be pharmacological sanctuaries. Parenteral administration of antiretroviral (ARV) drugs for treatment and prevention of HIV infection is an active area of drug development. The influence of route of administration on ARV tissue pharmacokinetics is not known.

OBJECTIVES

To investigate ARV pharmacokinetics in lymphatic and select non-lymphatic tissues (e.g. brain and testes) after intramuscular and subcutaneous administration compared with oral in BALB/c mice.

METHODS

Tissue concentrations of cobicistat, efavirenz, elvitegravir, maraviroc, rilpivirine, tenofovir alafenamide and tenofovir disoproxil fumarate were determined. The tissue penetration ratio (TPR) was the primary measure for comparison; a change in TPR arises from factors affecting tissue distribution controlling for changes in systemic bioavailability.

RESULTS

Intramuscular and subcutaneous delivery increased TPRs in the lymph node and spleen for 27 of 28 (96%) drug administration events. Decreased TPRs, however, were found in some tissues such as the brain and testes.

CONCLUSIONS

These results demonstrate a change in route of drug administration from oral to intramuscular or subcutaneous can change tissue uptake. This has implications for HIV pharmacotherapy. For example, HIV persists in lymphoid tissues despite long-term oral ARV therapy, and low ARV concentrations have been found in lymphoid tissues. The improved ARV lymphatic tissue bioavailability with intramuscular and subcutaneous administration allows future studies to investigate these routes of drug administration as a therapeutic manoeuvre to limit viral persistence and eliminate viral sanctuaries in the lymphatic tissues, which is a prerequisite for eradication of HIV.

Cross-validation of a high-performance liquid chromatography nevirapine plasma assay in a resource-limited setting in Zimbabwe

An international HIV pharmacology specialty laboratory (PSL) was established at the University of Zimbabwe to increase bioanalytical and investigator capacities. Quantitation of plasma nevirapine in samples from the AIDS Clinical Trials Group protocol 5279 was compared between the University of Nebraska Medical Center PSL and the University of Zimbabwe PSL. Both PSLs employed internally developed methods utilising reverse-phase high-performance liquid chromatography with ultraviolet detection. Eighty-seven percent of the cross-validation results exhibited ± 20% difference.

Nevirapine pharmacokinetics in HIV-infected persons receiving rifapentine and isoniazid for TB prevention

BACKGROUND

The use of rifamycin antibiotics for TB prevention carries a risk of detrimental drug-drug interactions with concomitantly used ART.

OBJECTIVES

To evaluate the interaction of the antiretroviral drug nevirapine in combination with 4 weeks of daily rifapentine and isoniazid for TB prevention in people living with HIV.

METHODS

Participants were individuals enrolled in the BRIEF-TB study receiving nevirapine and randomized to the rifapentine/isoniazid arm of the study. Participants provided sparse pharmacokinetic (PK) sampling at baseline and weeks 2 and 4 for trough nevirapine determination. Nevirapine apparent oral clearance (CL/F) was estimated and the geometric mean ratio (GMR) of CL/F prior to and during rifapentine/isoniazid was calculated.

RESULTS

Seventy-eight participants had evaluable PK data: 61 (78%) female, 51 (65%) black non-Hispanic and median (range) age of 40 (13-66) years. Median (IQR) nevirapine trough concentrations were: week 0, 7322 (5266-9302) ng/mL; week 2, 5537 (3552-8462) ng/mL; and week 4, 5388 (3516-8243) ng/mL. Sixty out of 78 participants (77%) had nevirapine concentrations ≥3000 ng/mL at both week 2 and 4. Median (IQR) nevirapine CL/F values were: week 0 pre-rifapentine/isoniazid, 2.03 (1.58-2.58) L/h; and during rifapentine/isoniazid, 2.62 (1.81-3.42) L/h. The GMR (90% CI) for nevirapine CL/F was 1.30 (1.26-1.33).

CONCLUSIONS

The CL/F of nevirapine significantly increased with concomitant rifapentine/isoniazid. The decrease in nevirapine trough concentrations during rifapentine/isoniazid therapy suggests induction of nevirapine metabolism, consistent with known rifapentine effects. The magnitude of this drug-drug interaction suggests daily rifapentine/isoniazid for TB prevention should not be co-administered with nevirapine-containing ART.

Plasma and intracellular pharmacokinetics of tenofovir disoproxil fumarate and emtricitabine in transgender women receiving feminizing hormone therapy

BACKGROUND

Transwomen have an increased risk of HIV acquisition compared with other adults. Drug-drug interactions between pre-exposure prophylaxis (PrEP) and gender-affirming therapy are cited as a reason for poor PrEP uptake among transwomen. We evaluated plasma tenofovir and emtricitabine pharmacokinetics and their active intracellular anabolites, tenofovir-diphosphate and emtricitabine-triphosphate, in transwomen receiving feminizing hormones.

METHODS

We enrolled HIV-negative transwomen (≥19 years) not receiving PrEP. Participants took oral tenofovir disoproxil fumarate/emtricitabine 300/200 mg daily for 14 days. Plasma was collected at 0 h (pre-dose), 0.5, 1, 2, 3, 4, 6, 8 and 12 h on day 14 post-tenofovir disoproxil fumarate/emtricitabine dose. The plasma AUC0-24 was calculated using the trapezoidal rule and compared with historical HIV-negative cisgender adults as geometric mean ratios (GMRs, 90% CI). Secondarily, tenofovir-diphosphate and emtricitabine-triphosphate from PBMCs collected at 0 h and 12 h were reported descriptively as geometric means (90% CI). Clinical trials registration: NCT03270969.

RESULTS

Among 15 transwomen (mean age 32 years), geometric mean tenofovir and emtricitabine plasma AUC0-24 were lower compared with controls: tenofovir, 2.10 versus 2.76 mg·h/L, GMR 0.76 (0.65-0.90), P = 0.01; emtricitabine, 9.15 versus 10.64 mg·h/L, GMR 0.86 (0.75-0.98), P = 0.07. Tenofovir-diphosphate and emtricitabine-triphosphate concentrations were higher than previously reported in the literature: 167.1 (146.6-190.5) fmol/106 cells and 15.4 (13.8-17.3) pmol/106 cells, respectively.

CONCLUSIONS

We observed lower plasma tenofovir and emtricitabine concentrations in transwomen compared with historical cisgender adults, yet intracellular tenofovir-diphosphate and emtricitabine-triphosphate concentrations were higher than previously reported in PBMCs. Understanding the differences of PrEP pharmacokinetics in plasma and tissue compartments and the resultant impact on efficacy remains important for transwomen.

Role of toll-like receptor 7/8 pathways in regulation of interferon response and inflammatory mediators during SARS-CoV2 infection and potential therapeutic options

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) is the causative agent of Corona Virus Disease 2019 (COVID-19). Lower production of type I and III interferons and higher levels of inflammatory mediators upon SARS-CoV2 infection contribute to COVID-19 pathogenesis. Optimal interferon production and controlled inflammation are essential to limit COVID-19 pathogenesis. However, the aggravated inflammatory response observed in COVID-19 patients causes severe damage to the host and frequently advances to acute respiratory distress syndrome (ARDS). Toll-like receptor 7 and 8 (TLR7/8) signaling pathways play a central role in regulating induction of interferons (IFNs) and inflammatory mediators in dendritic cells. Controlled inflammation is possible through regulation of TLR mediated response without influencing interferon production to reduce COVID-19 pathogenesis. This review focuses on inflammatory mediators that contribute to pathogenic effects and the role of TLR pathways in the induction of interferon and inflammatory mediators and their contribution to COVID-19 pathogenesis. We conclude that potential TLR7/8 agonists inducing antiviral interferon response and controlling inflammation are important therapeutic options to effectively eliminate SARS-CoV2 induced pathogenesis. Ongoing and future studies may provide additional evidence on their safety and efficacy to treat COVID-19 pathogenesis.

In-vitro Immunomodulatory activity of Azadirachta indica A.Juss. Ethanol: water mixture against HIV associated chronic CD4+ T-cell activation/ exhaustion

BACKGROUND

In Sub-Saharan Africa, herbal therapy continues to be utilized for HIV-1 disease management. However, the therapeutic benefits of these substances remain ambiguous. To date, little is known about the effects of these plant extracts on chronic CD4 + T-cell activation and exhaustion which is partly driven by HIV-1 associated microbial translocation.

METHODS

Effects of Azadirachta indica, Momordica foetida and Moringa oleifera ethanol: water mixtures on cell viability were evaluated using the Guava PCA system. Then, an in-vitro cell culture model was developed to mimic CD4+ T cell exposures to antigens following HIV-1 microbial translocation. In this, peripheral blood mononuclear cells (PBMCs) isolated from HIV negative (n = 13), viral load < 1000 copies per mL (n = 10) and viral load > 1000 copies per mL (n = 6) study participants from rural Uganda were treated with Staphylococcus enterotoxin B (SEB). Then, the candidate plant extract (A. indica) was added to test the potential to inhibit corresponding CD4+ T cell activation. Following BD Facs Canto II event acquisition, variations in %CD38, %CD69, Human Leukocyte Antigen -DR (HLA-DR), Programmed cell death protein 1 (PD-1), T-cell immunoglobulin and mucin domain-containing protein 3 (Tim-3), interferon gamma (IFN γ) and interleukin 2 (IL-2) CD4 + T cell expression were evaluated.

RESULTS

Following exposure to SEB, only A. indica demonstrated a concentration-dependent ability to downregulate the levels of CD4 + T cell activation. At the final concentration of 0.500 μg/mL of A. indica, a significant downregulation of CD4 + CD38 + HLA-DR+ expression was observed in HIV negative (p < 0.0001) and both HIV infected groups (P = 0.0313). This plant extract also significantly lowered SEB induced % CD4+ T cell HLADR, PD-1 and Tim-3 levels. PD-1 and CD69 markers were only significantly downmodulated in only the HIV negative ((p = 0.0001 and p = 0.0078 respectively) and viral load< 1000 copies per ml (p = 0.0078) groups.

CONCLUSION

A. indica exhibited the in-vitro immunomodulatory potential to inhibit the continuum of SEB induced CD4+ T-cell activation/ exhaustion without impacting general T-cell specific functions such as cytokine secretion. Additional studies are needed to confirm A. indica as a source of natural products for targeting persistent immune activation and inflammation during ART.

Pharmacogenetic interactions of rifapentine plus isoniazid with efavirenz or nevirapine

OBJECTIVES

The effect of rifapentine plus isoniazid on efavirenz pharmacokinetics was characterized in AIDS Clinical Trials Group protocol A5279 (NCT01404312). The present analyses characterize pharmacogenetic interactions between these drugs, and with nevirapine.

METHODS

A subset of HIV-positive individuals receiving efavirenz- or nevirapine-containing antiretroviral therapy in A5279 underwent pharmacokinetic evaluations at baseline, and again weeks 2 and 4 after initiating daily rifapentine plus isoniazid. Associations with polymorphisms relevant to efavirenz, nevirapine, isoniazid, and rifapentine pharmacokinetics were assessed.

RESULTS

Of 128 participants, 101 were evaluable for associations with rifapentine and its active 25-desacetyl metabolite, 87 with efavirenz, and 38 with nevirapine. In multivariable analyses, NAT2 slow acetylators had greater week 4 plasma concentrations of rifapentine (P = 2.6 × 10) and 25-desacetyl rifapentine (P = 7.0 × 10) among all participants, and in efavirenz and nevirapine subgroups. NAT2 slow acetylators also had greater plasma efavirenz and nevirapine concentration increases from baseline to week 4, and greater decreases from baseline in clearance. CYP2B6 poor metabolizers had greater efavirenz concentrations at all weeks and greater nevirapine concentrations at baseline. None of 47 additional polymorphisms in 11 genes were significantly associated with pharmacokinetics.

CONCLUSIONS

Among HIV-positive individuals receiving efavirenz or nevirapine, and who then initiated rifapentine plus isoniazid in A5279, NAT2 slow acetylators had greater rifapentine and 25-desacetyl rifapentine concentrations, and greater increases from baseline in plasma efavirenz and nevirapine concentrations. These associations are likely mediated by greater isoniazid exposure in NAT2 slow acetylators.

HIV-1 Integrase Inhibitors: A Comparative Review of Efficacy and Safety

The newest class of antiretrovirals for all persons living with HIV are the integrase strand transfer inhibitors (INSTIs). Since 2007, five INSTIs have been introduced: raltegravir, elvitegravir, dolutegravir, bictegravir, and cabotegravir. The INSTIs have favorable pharmacokinetic and pharmacodynamic properties, which contribute to both their effectiveness and their ease of use. With the exception of cabotegravir, each INSTI is US Food and Drug Administration approved for treatment-naïve individuals initiating antiretroviral therapy. All of the INSTIs, except raltegravir, are approved for antiretroviral treatment simplification for virologically suppressed patients without INSTI resistance. Data also support the use of dolutegravir and raltegravir in individuals with antiretroviral resistance as part of an optimized antiretroviral regimen. INSTIs are generally well tolerated by people living with HIV compared with older classes of antiretrovirals, but emerging data suggest that some INSTIs contribute to weight gain. Due to their efficacy, safety, and ease of use, HIV treatment guidelines recommend oral INSTIs as preferred components of antiretroviral therapy for individuals initiating therapy. The newest INSTI, cabotegravir, represents an alternative to oral administration of life-long antiretroviral therapy with the availability of a long-acting injectable formulation. This review summarizes the current use of INSTIs in adults living with HIV, highlighting the similarities and differences within the class related to pharmacodynamics, pharmacokinetics, safety, dosing, and administration that contribute to their role in modern antiretroviral therapy.

Transcriptomic approach predicts a major role for transforming growth factor beta type 1 pathway in L-Dopa-induced dyskinesia in parkinsonian rats

Dyskinesia induced by long-term L-Dopa (LID) therapy in Parkinson disease is associated with altered striatal function whose molecular bases remain unclear. Here, a transcriptomic approach was applied for comprehensive analysis of distinctively regulated genes in striatal tissue, their specific pathways, and functional- and disease-associated networks in a rodent model of LID. This approach has identified transforming growth factor beta type 1 (TGFβ1) as a highly upregulated gene in dyskinetic animals. TGFβ1 pathway is a top aberrantly regulated pathway in the striatum following LID development based on differentially expressed genes (> 1.5 fold change and P < 0.05). The induction of TGFβ1 pathway specific genes, TGFβ1, INHBA, AMHR2 and PMEPA1 was also associated with regulation of NPTX2, PDP1, SCG2, SYNPR, TAC1, TH, TNNT1 genes. Transcriptional network and upstream regulator analyses have identified AKT-centered functional and ERK-centered disease networks revealing the association of TGFβ1, IL-1β and TNFα with LID development. Therefore, results support that TGFβ1 pathway is a major contributor to the pathogenic mechanisms of LID.

Assessing the lymphoid tissue bioavailability of antiretrovirals in human primary lymphoid endothelial cells and in mice

BACKGROUND

The secondary lymphoid tissues (LTs), lymph nodes (LNs) and gut-associated lymphoid tissue (GALT) are considered reservoirs for HIV. Antiretrovirals (ARVs) have lower penetration into LT. In vitro models predictive of ARV LT penetration have not been established.

OBJECTIVES

To develop an in vitro model of LT bioavailability using human lymphoid endothelial cells (HLECs) and investigate its predictability with in vivo pharmacokinetic (PK) studies in mice.

METHODS

ARV bioavailability in HLECs was evaluated at the maximum plasma concentration (Cmax) observed in HIV-infected patients. ARVs were: abacavir, atazanavir, darunavir, dolutegravir, efavirenz, elvitegravir, emtricitabine, maraviroc, raltegravir, rilpivirine, ritonavir, tenofovir disoproxil fumarate and the PK booster cobicistat. The LT PK of representative drugs showing high (efavirenz), intermediate (dolutegravir) and low (emtricitabine) HLEC bioavailability was investigated in BALB/c mice given 50/10/30 mg/kg efavirenz/dolutegravir/emtricitabine orally, daily for 3 days. The concordance of in vitro and in vivo ARV bioavailability was examined.

RESULTS

ARVs showed high (>67th percentile; rilpivirine, efavirenz, elvitegravir and cobicistat), intermediate (67th-33rd percentile; ritonavir, tenofovir disoproxil fumarate, dolutegravir and maraviroc) and low (<33rd percentile; atazanavir, darunavir, raltegravir, emtricitabine and abacavir) HLEC bioavailability. The hierarchy of efavirenz, dolutegravir and emtricitabine bioavailability in LN, gut and brain tissues of mice was: efavirenz>dolutegravir>emtricitabine.

CONCLUSIONS

ARVs displayed distinct HLEC penetration patterns. PK studies of representative ARVs in LT of mice were concordant with HLEC bioavailability. These findings support further development of this approach and its translational predictability in humans.

Immuno-epidemiology and pathophysiology of coronavirus disease 2019 (COVID-19)

Occasional zoonotic viral attacks on immunologically naive populations result in massive death tolls that are capable of threatening human survival. Currently, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the infectious agent that causes coronavirus disease (COVID-19), has spread from its epicenter in Wuhan China to all parts of the globe. Real-time mapping of new infections across the globe has revealed that variable transmission patterns and pathogenicity are associated with differences in SARS-CoV-2 lineages, clades, and strains. Thus, we reviewed how changes in the SARS-CoV-2 genome and its structural architecture affect viral replication, immune evasion, and transmission within different human populations. We also looked at which immune dominant regions of SARS-CoV-2 and other coronaviruses are recognized by Major Histocompatibility Complex (MHC)/Human Leukocyte Antigens (HLA) genes and how this could impact on subsequent disease pathogenesis. Efforts were also placed on understanding immunological changes that occur when exposed individuals either remain asymptomatic or fail to control the virus and later develop systemic complications. Published autopsy studies that reveal alterations in the lung immune microenvironment, morphological, and pathological changes are also explored within the context of the review. Understanding the true correlates of protection and determining how constant virus evolution impacts on host-pathogen interactions could help identify which populations are at high risk and later inform future vaccine and therapeutic interventions.

The Lymphoid Tissue Pharmacokinetics of Tenofovir Disoproxil Fumarate and Tenofovir Alafenamide in HIV-Infected Persons

The secondary lymphoid tissues (LT), lymph nodes (LN) and gut-associated lymphoid tissue are the primary sites of HIV replication and where the latent pool of virus is maintained. We compared the pharmacokinetics of tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF) in LT of 13 HIV-infected persons receiving a TDF-containing antiretroviral regimen who subsequently switched to a TAF-containing regimen. Study participants were on stable antiretroviral therapy for ≥12 months with plasma HIV-RNA < 48 copies/mL for 6 months before enrollment and entry CD4 cell counts > 300 cells/µL. Intracellular concentrations of tenofovir-diphosphate (TFV-DP) and emtricitabine-triphosphate (FTC-TP) were quantified in PBMCs and in mononuclear cells obtained from LN, ileum and rectal tissues. With TAF, the TFV-DP concentrations in PBMCs and LN were 7.3-fold and 6.4-fold higher (ratios of geometric means of TAF to TDF), respectively, compared with TDF; ileal and rectal concentrations, however, were lower with geometric mean ratios of 0.14 and 0.18, respectively. A statistically significant relationship was observed between PBMC and LN concentrations of TFV-DP. During TDF-containing therapy, the expected effect of cobicistat to increase TFV plasma concentrations was observed, as were higher TFV-DP concentrations in PBMCs and mononuclear cells from LN, ileum and rectal tissues. The higher TFV-DP concentrations achieved with TAF in the LN provides the first human correlate of the observation in animals that TAF produced higher tenofovir LN concentrations. The ability to increase LN concentrations allows investigations of whether antiretroviral regimens with improved LN pharmacokinetics elicit a more complete virologic response in that compartment.

High-dose rifapentine with or without moxifloxacin for shortening treatment of pulmonary tuberculosis: Study protocol for TBTC study 31/ACTG A5349 phase 3 clinical trial

INTRODUCTION

Phase 2 clinical trials of tuberculosis treatment have shown that once-daily regimens in which rifampin is replaced by high dose rifapentine have potent antimicrobial activity that may be sufficient to shorten overall treatment duration. Herein we describe the design of an ongoing phase 3 clinical trial testing the hypothesis that once-daily regimens containing high dose rifapentine in combination with other anti-tuberculosis drugs administered for four months can achieve cure rates not worse than the conventional six-month treatment regimen.

METHODS/DESIGN

S31/A5349 is a multicenter randomized controlled phase 3 non-inferiority trial that compares two four-month regimens with the standard six-month regimen for treating drug-susceptible pulmonary tuberculosis in HIV-negative and HIV-positive patients. Both of the four-month regimens contain high-dose rifapentine instead of rifampin, with ethambutol replaced by moxifloxacin in one regimen. All drugs are administered seven days per week, and under direct observation at least five days per week. The primary outcome is tuberculosis disease-free survival at twelve months after study treatment assignment. A total of 2500 participants will be randomized; this gives 90% power to show non-inferiority with a 6.6% margin of non-inferiority.

DISCUSSION

This phase 3 trial formally tests the hypothesis that augmentation of rifamycin exposures can shorten tuberculosis treatment to four months. Trial design and standardized implementation optimize the likelihood of obtaining valid results. Results of this trial may have important implications for clinical management of tuberculosis at both individual and programmatic levels.

TRIAL REGISTRATION

NCT02410772. Registered 8 April 2015,https://www.clinicaltrials.gov/ct2/show/NCT02410772?term=02410772&rank=1.

Evaluating emtricitabine + rilpivirine + tenofovir alafenamide in combination for the treatment of HIV-infection

Introduction: Antiretroviral therapy (ART) is recommended for all people who are living with HIV to suppress viral load and to stop the progression and transmission of HIV-1. Fixed-dose combinations of antiretrovirals largely reduce pill burden.Areas covered: The authors first provide an overview of the use of non-nucleoside reverse transcriptase inhibitor (NNRTI) based therapy in HIV care. They then summarize the properties of each drug in the fixed-dose combination of tenofovir alafenamide/emtricitabine/rilpivirine/(TAF/FTC/RPV). The efficacy and safety of each component and the combination as a whole are reviewed: FTC is non-inferior to lamivudine (3TC) at assessed dosages; TAF was non-inferior to tenofovir disoproxil fumarate (TDF); the viral efficacy of RPV is non-inferior with EFV at the assessed dosage; TAF/FTC/RPV is non-inferior in efficacy but shows less of a decline in bone mineral density and renal function compared to TDF/FTC/RPV. Finally, adverse effects and drug-drug interaction data with FTC/RPV/TAF are discussed.Expert opinion: TAF/FTC/RPV can be used as an initial regimen for people living with HIV whose HIV RNA <100,000 copies/ml and CD4 cell count > 200 cells/mm³ when INSTI-based regimens are not a treatment option. Future antiretroviral therapy development may focus on dual therapy-based regimens containing RPV, particularly as long-acting formulations.

Modelling the long-acting administration of anti-tuberculosis agents using PBPK: a proof of concept study

SETTING

Anti-tuberculosis formulations necessitate uninterrupted treatment to cure tuberculosis (TB), but are characterised by suboptimal adherence, which jeopardises therapeutic efficacy. Long-acting injectable (LAI) formulations or implants could address these associated issues.

OBJECTIVE

niazid, rifapentine, bedaquiline and delamanid-in adults for treatment for latent tuberculous infection (LTBI).

DESIGN

PBPK models were developed and qualified against available clinical data by integrating drug physicochemical properties and in vitro and population pharmacokinetic data into a mechanistic description of drug distribution. Combinations of optimal dose and release rates were simulated such that plasma concentrations were maintained over the epidemiological cut-off or minimum inhibitory concentration for the dosing interval.

RESULTS

The PBPK model identified 1500 mg of delamanid and 250 mg of rifapentine as sufficient doses for monthly intramuscular administration, if a formulation or device can deliver the required release kinetics of 0.001-0.0025 h-1 and 0.0015-0.0025 h-1, respectively. Bedaquiline and isoniazid would require weekly to biweekly intramuscular dosing.

CONCLUSION

We identified the theoretical doses and release rates of LAI anti-tuberculosis formulations. Such a strategy could ease the problem of suboptimal adherence provided the associated technological complexities for LTBI treatment are addressed.

Long-acting formulations for the treatment of latent tuberculous infection: opportunities and challenges

Long-acting/extended-release drug formulations have proved very successful in diverse areas of medicine, including contraception, psychiatry and, most recently, human immunodeficiency virus (HIV) disease. Though challenging, application of this technology to anti-tuberculosis treatment could have substantial impact. The duration of treatment required for all forms of tuberculosis (TB) put existing regimens at risk of failure because of early discontinuations and treatment loss to follow-up. Long-acting injections, for example, administered every month, could improve patient adherence and treatment outcomes. We review the state of the science for potential long-acting formulations of existing tuberculosis drugs, and propose a target product profile for new formulations to treat latent tuberculous infection (LTBI). The physicochemical properties of some anti-tuberculosis drugs make them unsuitable for long-acting formulation, but there are promising candidates that have been identified through modeling and simulation, as well as other novel agents and formulations in preclinical testing. An efficacious long-acting treatment for LTBI, particularly for those co-infected with HIV, and if coupled with a biomarker to target those at highest risk for disease progression, would be an important tool to accelerate progress towards TB elimination.

A pharmacist-led medication switch protocol in an academic HIV clinic: patient knowledge and satisfaction

Background

Tenofovir alafenamide (TAF) is associated with less renal and bone toxicity compared with tenofovir disoproxil (TDF). TAF's recent FDA approval has spurred HIV providers to consider switching antiretroviral therapy (ART) regimens containing TDF to TAF to minimize long term risks. Patient views on the process of such medication switches have not been explored.

Methods

Patients taking elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate (E/C/F/TDF) following the Food and Drug Administration’s (FDA) approval of elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (E/C/F/TAF) received medication education from an HIV pharmacist prior to switching to the tenofovir alafenamide (TAF) formulation. Patients were asked to complete a cross-sectional survey assessing satisfaction with the switch process and knowledge about the new medication 4 to 8 weeks post-switch.

Results

Sixty five patients completed the switch and 57 (88%) completed a follow-up survey. Most (86%) reported understanding why the switch was made, while 91% correctly identified that TAF is associated with reduced renal toxicity, and 73% correctly identified that TAF is associated with reduced bone toxicity. No statistically significant difference was found in satisfaction with or understanding of why the medication switch was made when assessed by sex, age, race, or education, but there was a trend toward significance in the distribution of answers based on education level with those with a high school diploma, General Educational Development (GED) or less being more likely to be satisfied with the medication switch (p = 0.074).

Conclusions

Education from an ambulatory clinic-based HIV pharmacist resulted in high rates of patient satisfaction and understanding of the switch from TDF to TAF-containing ART.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3226-2) contains supplementary material, which is available to authorized users.

Transplantation of CCR5∆32 Homozygous Umbilical Cord Blood in a Child With Acute Lymphoblastic Leukemia and Perinatally Acquired HIV Infection

Background

Allogeneic hematopoietic cell transplantation (allo-HCT) in a CCR5∆32 homozygous donor resulted in HIV cure. Understanding how allo-HCT impacts the HIV reservoir will inform cure strategies.

Methods

A 12-year-old with perinatally acquired, CCR5-tropic HIV and acute lymphoblastic leukemia underwent myeloablative conditioning and umbilical cord blood (UCB) transplantation from a CCR5∆32 homozygous donor. Peripheral blood mononuclear cells (PBMCs) and the rectum were sampled pre- and post-transplant. The brain, lung, lymph node (LN), stomach, duodenum, ileum, and colon were sampled 73 days after transplantation (day +73), when the patient died from graft-vs-host disease. Droplet digital polymerase chain reaction (ddPCR) and in situ hybridization (ISH) were used detect the HIV reservoir in tissues. CCR5 and CD3 expression in the LN was assessed using immunohistochemistry (IHC).

Results

HIV DNA (vDNA) was detected in PBMCs by ddPCR pretransplant but not post-transplant. vDNA was detected by ISH in the rectum at days –8 and +22, and in the LN, colon, lung, and brain day +73. vDNA was also detected in the lung by ddPCR. IHC revealed CCR5+CD3+ cells in the LN postmortem.

Conclusions

HIV was detected in multiple tissues 73 days after CCR5∆32 homozygous UCB allo-HCT despite myeloablative conditioning and complete donor marrow engraftment. These results highlight the importance of analyzing tissue during HIV cure interventions and inform the choice of assay used to detect HIV in tissue reservoirs.

Development, validation and utilization of a highly sensitive LC-MS/MS method for quantification of levonorgestrel released from a subdermal implant in human plasma

Levonorgestrel (LNG) is a synthetic progestin that is available in oral contraceptive tablets, a subdermal implant, and an intrauterine system for contraception. LNG pharmacokinetics are a pivotal determinant of contraceptive efficacy and essential in assessing drug-drug interactions influencing LNG exposure following different routes of LNG administration. A highly sensitive LC-MS/MS method was developed and validated to quantify levonorgestrel in human plasma. Liquid-liquid extraction was utilized with a sample volume of 500 μL to extract levonorgestrel from plasma. Chromatographic separation of LNG was achieved with a Fortis™ C18 (3 μm: 100 mm × 2.1 mm) reverse phase analytical column. The mobile phases consisted of de-ionized water plus 0.1% NH4OH (100:0.1%, v/v) (A), and methanol plus 0.1% NH4OH (100:0.1%, v/v) (B) delivered as a gradient at a flow rate of 400 μL/min. Detection of LNG and internal standard (D-(-)-norgestrel-d7) was achieved using positive polarity mode monitoring at 313.2-245.2 amu and 320.1-251.2 amu, respectively. The assay was linear over the calibration range of 49.6 to 1500 pg/mL. This method was used to quantify plasma LNG released by subdermal implant in support of a drug interaction study among women with HIV receiving efavirenz- or nevirapine-based antiretroviral therapy.

Adipocytes impair efficacy of antiretroviral therapy

Adequate distribution of antiretroviral drugs to infected cells in HIV patients is critical for viral suppression. In humans and primates, HIV- and SIV-infected CD4 T cells in adipose tissues have recently been identified as reservoirs for infectious virus. To better characterize adipose tissue as a pharmacological sanctuary for HIV-infected cells, in vitro experiments were conducted to assess antiretroviral drug efficacy in the presence of adipocytes, and drug penetration in adipose tissue cells (stromal-vascular-fraction cells and mature adipocytes) was examined in treated humans and monkeys. Co-culture experiments between HIV-1-infected CD4 T cells and primary human adipocytes showed that adipocytes consistently reduced the antiviral efficacy of the nucleotide reverse transcriptase inhibitor tenofovir and its prodrug forms tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF). In HIV-infected persons, LC-MS/MS analysis of intracellular lysates derived from adipose tissue stromal-vascular-fraction cells or mature adipocytes suggested that integrase inhibitors penetrate adipose tissue, whereas penetration of nucleoside/nucleotide reverse transcriptase inhibitors such as TDF, emtricitabine, abacavir, and lamivudine is restricted. The limited distribution and functions of key antiretroviral drugs within fat depots may contribute to viral persistence in adipose tissue.

Comparative Clinical Pharmacokinetics and Pharmacodynamics of HIV-1 Integrase Strand Transfer Inhibitors

Dolutegravir (DTG), elvitegravir (EVG) and raltegravir (RAL) are members of the latest class of antiretrovirals (ARVs) that have become available to treat human immunodeficiency virus (HIV) infection: integrase strand transfer inhibitors (INSTIs). INSTIs are potent inhibitors of the HIV integrase enzyme, with protein binding-adjusted concentration inhibiting viral replication by 90/95 % [IC_90/95] values in the low nanogram per millilitre range, and they retain antiviral activity against strains of HIV with acquired resistance to other classes of ARVs. Each of the INSTIs has unique pharmacokinetic/pharmacodynamic properties, influencing its role in clinical use in specific subsets of patients. RAL and DTG have minimal drug-drug interaction profiles, as their metabolism has minimal cytochrome P450 (CYP) involvement. Conversely, EVG metabolism occurs primarily via CYP3A4 and requires pharmacokinetic boosting to achieve systemic exposures amenable to once-daily dosing. EVG and DTG have the added benefit of availability of fixed-dose combination tablets, allowing for convenient and simplified ARV regimens. RAL is the only INSTI to be listed as a preferred agent in the current US perinatal treatment guidelines. All three INSTIs are recommended regimens for treatment-naïve individuals in the US adult and adolescent HIV treatment guidelines. This review summarizes and compares the pharmacokinetics and pharmacodynamics of the INSTIs, and describes specific pharmacokinetic considerations for special patient conditions: hepatic impairment, renal dysfunction, pregnancy and co-infections.

Current strategies to treat tuberculosis

Tuberculosis (TB) has been a leading cause of death for more than a century. While effective therapies exist, treatment is long and cumbersome. TB control is complicated by the overlapping problems created by global inadequacy of public health infrastructures, the interaction of the TB and human immunodeficiency virus (HIV) epidemics, and the emergence of drug-resistant TB. After a long period of neglect, there is now significant progress in the development of novel treatment regimens for TB. Focusing on treatment for active disease, we review pathways to TB regimen development and the new and repurposed anti-TB agents in clinical development.

Impact of efavirenz pharmacokinetics and pharmacogenomics on neuropsychological performance in older HIV-infected patients

BACKGROUND

Pharmacokinetics (PK) and pharmacodynamics of efavirenz and its 8-hydroxy metabolite (8-OH-efavirenz) have not been robustly evaluated in older HIV-infected persons.

OBJECTIVES

We investigated relationships between neuropsychological (NP) performance and efavirenz and 8-OH-efavirenz PK in HIV-infected individuals >50 years of age.

METHODS

A cross-sectional study of HIV-infected adults on an efavirenz-containing regimen. The 12 and 18 h post-dose plasma efavirenz and 8-OH-efavirenz were quantified. CYP2B6 polymorphisms were investigated. Participants underwent neuropsychological tests; surveys were used for depression, sleep quality and anxiety. We investigated potential correlations of efavirenz and 8-OH-efavirenz plasma concentrations with NP performance, sleep, depression, anxiety and CYP2B6 polymorphisms.

RESULTS

Thirty participants (24 men and 6 women) with mean age 57 years (range 50-68). Plasma efavirenz concentrations did not correlate with NP performance; however, higher plasma 8-OH-efavirenz correlated with better learning (P = 0.002), language (P = 0.002) and total NP z-scores (P = 0.003). No correlation was seen for efavirenz or 8-OH-efavirenz with sleep, anxiety or depression. Median 12 and 18 h efavirenz plasma concentrations were 1967 ng/mL (IQR 1476-2394) and 1676 ng/mL (IQR 1120-2062), respectively. Median 12 and 18 h 8-OH-efavirenz plasma concentrations were 378 ng/mL (IQR 223-589) and 384 ng/mL (IQR 216-621), respectively. CYP2B6 G516T was associated with significantly higher plasma efavirenz at 12 and 18 h (P = 0.02) but not worse NP function.

CONCLUSIONS

Better neurocognitive functioning was associated with higher 8-OH-efavirenz but not efavirenz plasma concentrations. No correlation was observed with sleep or depression. These findings point to a need for greater understanding of the metabolic profile of efavirenz and 8-OH-efavirenz in plasma and the CNS and relationships with antiviral effect and neurotoxicity.

Efavirenz Pharmacokinetics and Pharmacodynamics in HIV-Infected Persons Receiving Rifapentine and Isoniazid for Tuberculosis Prevention

BACKGROUND

Concomitant use of rifamycins to treat or prevent tuberculosis can result in subtherapeutic concentrations of antiretroviral drugs. We studied the interaction of efavirenz with daily rifapentine and isoniazid in human immunodeficiency virus (HIV)-infected individuals receiving a 4-week regimen to prevent tuberculosis.

METHODS

Participants receiving daily rifapentine and isoniazid with efavirenz had pharmacokinetic evaluations at baseline and weeks 2 and 4 of concomitant therapy. Efavirenz apparent oral clearance was estimated and the geometric mean ratio (GMR) of values before and during rifapentine and isoniazid was calculated. HIV type 1 (HIV-1) RNA was measured at baseline and week 8.

RESULTS

Eighty-seven participants were evaluable: 54% were female, and the median age was 35 years (interquartile range [IQR], 29-44 years). Numbers of participants with efavirenz concentrations ≥1 mg/L were 85 (98%) at week 0; 81 (93%) at week 2; 78 (90%) at week 4; and 75 (86%) at weeks 2 and 4. Median efavirenz apparent oral clearance was 9.3 L/hour (IQR, 6.42-13.22 L/hour) at baseline and 9.8 L/hour (IQR, 7.04-15.59 L/hour) during rifapentine/isoniazid treatment (GMR, 1.04 [90% confidence interval, .97-1.13]). Seventy-nine of 85 (93%) participants had undetectable HIV-1 RNA (<40 copies/mL) at entry; 71 of 75 (95%) participants had undetectable HIV-1 RNA at week 8. Two participants with undetectable HIV-1 RNA at study entry were detectable (43 and 47 copies/mL) at week 8.

CONCLUSIONS

The proportion of participants with midinterval efavirenz concentrations ≥1 mg/L did not cross below the prespecified threshold of >80%, and virologic suppression was maintained. Four weeks of daily rifapentine plus isoniazid can be coadministered with efavirenz without clinically meaningful reductions in efavirenz mid-dosing concentrations or virologic suppression.

CLINICAL TRIALS REGISTRATION

NCT 01404312.

Plasma and Intracellular Pharmacokinetics of Tenofovir Disoproxil Fumarate 300 mg Every 48 Hours vs 150 mg Once Daily in HIV-Infected Adults With Moderate Renal Function Impairment

BACKGROUND

The approved tenofovir disoproxil fumarate (TDF) dose of 300 mg every 48 hours for adults with moderate renal impairment is often confusing and inconvenient. Using a new TDF formulation, we compared the pharmacokinetics of the standard dose with a dose of 150 mg once daily in HIV-infected adults.

METHODS

This was an open-label pharmacokinetic study. Virologically suppressed HIV-infected adults with a creatinine clearance 30 to <50 mL/minute receiving TDF 300 mg every 48 hours as part of a nonnucleoside reverse transcriptase inhibitor (NNRTI)- or lopinavir/ritonavir (LPV/r)-based regimen were enrolled. Intensive 48-hour blood sampling for pharmacokinetic assessment was performed at enrollment, after which the TDF dose was changed to 150 mg once daily. Two weeks later, 24-hour blood sampling was performed; subjects then returned to the standard dose. Tenofovir (TFV) pharmacokinetic parameters were calculated using a noncompartmental analysis.

RESULTS

Forty adults (55% female) were enrolled: 20 receiving NNRTI-based and 20 receiving LPV/r-based treatment. Median age was 56 years (range, 44-65 years), weight 51 kg (range, 38-80 kg), and creatinine clearance 43.9 mL/minute (range, 30.9-49.7 mL/minute). The TFV geometric mean ratio of the area under the curve (AUC0-48 h) for every 24 hours vs every 48 hours was 1.09 (90% confidence interval [CI], .98-1.22) and 1.00 (90% CI, .92-1.09) for patients receiving NNRTI- and LPV/r-based treatment, respectively. Concomitant LPV/r use markedly increased TFV plasma concentrations, and AUC0-48 h was 67% higher with the standard dose, whereas no differences in intracellular TFV diphosphate concentrations were observed. All subjects remained virologically suppressed, and no drug-related adverse events were reported.

CONCLUSIONS

TDF 150 mg every 24 hours provides comparable systemic exposure to the standard dose of 300 mg every 48 hours in patients with moderate renal impairment.

CLINICAL TRIALS REGISTRATION

NCT01671982.

Impact of an electronic medical record on the incidence of antiretroviral prescription errors and HIV pharmacist reconciliation on error correction among hospitalized HIV-infected patients

BACKGROUND

Previous review of admissions from 2009-2011 in our institution found a 35.1% error rate in antiretroviral (ART) prescribing, with 55% of errors never corrected. Subsequently, our institution implemented a unified electronic medical record (EMR) and we developed a medication reconciliation process with an HIV pharmacist. We report the impact of the EMR on incidence of errors and of the pharmacist intervention on time to error correction.

METHODS

Prospective medical record review of HIV-infected patients hospitalized for >24 h between 9 March 2013 and 10 March 2014. An HIV pharmacist reconciled outpatient ART prescriptions with inpatient orders within 24 h of admission. Prescribing errors were classified and time to error correction recorded. Error rates and time to correction were compared to historical data using relative risks (RR) and logistic regression models.

RESULTS

43 medication errors were identified in 31/186 admissions (16.7%). The incidence of errors decreased significantly after EMR (RR 0.47, 95% CI 0.34, 0.67). Logistic regression adjusting for gender and race/ethnicity found that errors were 61% less likely to occur using the EMR (95% CI 40%, 75%; P<0.001). All identified errors were corrected, 65% within 24 h and 81.4% within 48 h. Compared to historical data where only 31% of errors were corrected in <24 h and 55% were never corrected, errors were 9.4× more likely to be corrected within 24 h with HIV pharmacist intervention (P<0.001).

CONCLUSIONS

Use of an EMR decreased the error rate by more than 50% but despite this, ART errors remained common. HIV pharmacist intervention was key to timely error correction.