Body weight and blood pressure changes on dolutegravir-, efavirenz- or atazanavir-based antiretroviral therapy in Zimbabwe: a longitudinal study.

INTRODUCTION: Dolutegravir (DTG) is widely used for antiretroviral therapy (ART). We compared weight and blood pressure trends and examined the association between high blood pressure and weight gain among people living with HIV (PLHIV) switching to or starting DTG-based, efavirenz (EFV)-based and ritonavir-boosted atazanavir (ATV/r)-based ART in Zimbabwe. METHODS: PLHIV aged 18 years or older who started or switched to DTG, EFV or ATV/r-based ART between January 2004 and June 2022 at Newlands Clinic in Harare, Zimbabwe, were eligible. Weight was measured at all visits (Seca floor scales); blood pressure only at clinician-led visits (Omron M2 sphygmomanometer). We used Bayesian additive models to estimate trends in weight gain and the proportion with high blood pressure (systolic >140 mmHg or diastolic >90 mmHg) in the first 2 years after starting or switching the regimen. Finally, we examined whether trends in the proportion with high blood pressure were related to weight change. RESULTS: We analysed 99,969 weight and 35,449 blood pressure records from 9487 adults (DTG: 4593; EFV: 3599; ATV/r: 1295). At 24 months after starting or switching to DTG, estimated median weight gains were 4.54 kg (90% credibility interval 3.88-5.28 kg) in women and 3.71 kg (3.07-4.45 kg) in men, around twice that observed for ATV/r and over four-times the gain observed for EFV. Prevalence of high blood pressure among PLHIV receiving DTG-based ART increased from around 5% at baseline to over 20% at 24 months, with no change in PLHIV receiving EFV- or ATV/r-based ART. High blood pressure in PLHIV switching to DTG was associated with weight gain, with stronger increases in the proportion with high blood pressure for larger weight gains. CONCLUSIONS: Among PLHIV starting ART or switching to a new regimen, DTG-based ART was associated with larger weight gains and a substantial increase in the prevalence of high blood pressure. Routine weight and blood pressure measurement and interventions to lower blood pressure could benefit PLHIV on DTG-based ART. Further studies are needed to elucidate the mechanisms and reversibility of these changes after discontinuation of DTG.

Virologic outcomes on dolutegravir-, atazanavir-, or efavirenz-based ART in urban Zimbabwe: A longitudinal study.

There are few data from sub-Saharan Africa on the virological outcomes associated with second-line ART based on protease inhibitors or dolutegravir (DTG). We compared viral load (VL) suppression among people living with HIV (PLWH) on atazanavir (ATV/r)- or DTG-based second-line ART with PLWH on efavirenz (EFV)-based first-line ART. We analyzed data from the electronic medical records system of Newlands Clinic in Harare, Zimbabwe. We included individuals aged ≥12 years when commencing first-line EFV-based ART or switching to second-line DTG- or ATV/r-based ART with ≥24 weeks follow-up after start or switch. We computed suppression rates (HIV VL <50 copies/mL) at weeks 12, 24, 48, 72, and 96 and estimated the probability of VL suppression by treatment regimen, time since start/switch of ART, sex, age, and CD4 cell count (at start/switch) using logistic regression in a Bayesian framework. We included 7013 VL measurements of 1049 PLWH (61% female) initiating first-line ART and 1114 PLWH (58% female) switching to second-line ART. Among those switching, 872 (78.3%) were switched to ATV/r and 242 (21.7%) to DTG. VL suppression was lower in second-line ART than first-line ART, except at week 12, when those on DTG showed higher suppression than those on EFV (aOR 2.10, 95%-credible interval [CrI] 1.48-3.00) and ATV/r-based regimens (aOR 1.87, 95%-CrI 1.32-2.71). For follow-up times exceeding 24 weeks however, first-line participants demonstrated significantly higher VL suppression than second-line, with no evidence for a difference between DTG and ATV/r. Notably, from week 48 onward, VL suppression seemed to stabilize across all regimen groups, with an estimated 89.1% (95% CrI 86.9-90.9%) VL suppression in EFV, 74.5% (95%-CrI 68.0-80.7%) in DTG, and 72.9% (95%-CrI 69.5-76.1%) in ATV/r at week 48, showing little change for longer follow-up times. Virologic monitoring and adherence support remain essential even in the DTG era to prevent second-line treatment failure in settings with limited treatment options.

Preclinical characterization of a non-peptidomimetic HIV protease inhibitor with improved metabolic stability.

Protease inhibitors (PIs) remain an important component of antiretroviral therapy for the treatment of HIV-1 infection due to their high genetic barrier to resistance development. Nevertheless, the two most commonly prescribed HIV PIs, atazanavir and darunavir, still require co-administration with a pharmacokinetic boosting agent to maintain sufficient drug plasma levels which can lead to undesirable drug-drug interactions. Herein, we describe GS-9770, a novel investigational non-peptidomimetic HIV PI with unboosted once-daily oral dosing potential due to improvements in its metabolic stability and its pharmacokinetic properties in preclinical animal species. This compound demonstrates potent inhibitory activity and high on-target selectivity for recombinant HIV-1 protease versus other aspartic proteases tested. In cell culture, GS-9770 inhibits Gag polyprotein cleavage and shows nanomolar anti-HIV-1 potency in primary human cells permissive to HIV-1 infection and against a broad range of HIV subtypes. GS-9770 demonstrates an improved resistance profile against a panel of patient-derived HIV-1 isolates with resistance to atazanavir and darunavir. In resistance selection experiments, GS-9770 prevented the emergence of breakthrough HIV-1 variants at all fixed drug concentrations tested and required multiple protease substitutions to enable outgrowth of virus exposed to escalating concentrations of GS-9770. This compound also remained fully active against viruses resistant to drugs from other antiviral classes and showed no in vitro antagonism when combined pairwise with drugs from other antiretroviral classes. Collectively, these preclinical data identify GS-9770 as a potent, non-peptidomimetic once-daily oral HIV PI with potential to overcome the persistent requirement for pharmacological boosting with this class of antiretroviral agents.

Enhanced antifungal activity of posaconazole against Candida auris by HIV protease inhibitors, atazanavir and saquinavir.

The increasing incidence and dissemination of multidrug-resistant Candida auris represents a serious global threat. The emergence of pan-resistant C. auris exhibiting resistance to all three classes of antifungals magnifies the need for novel therapeutic interventions. We identified that two HIV protease inhibitors, atazanavir and saquinavir, in combination with posaconazole exhibited potent activity against C. auris in vitro and in vivo. Both atazanavir and saquinavir exhibited a remarkable synergistic activity with posaconazole against all tested C. auris isolates and other medically important Candida species. In a time-kill assay, both drugs restored the fungistatic activity of posaconazole, resulting in reduction of 5 and 5.6 log10, respectively. Furthermore, in contrast to the individual drugs, the two combinations effectively inhibited the biofilm formation of C. auris by 66.2 and 81.2%, respectively. Finally, the efficacy of the two combinations were tested in a mouse model of C. auris infection. The atazanavir/posaconazole and saquinavir/posaconazole combinations significantly reduced the C. auris burden in mice kidneys by 2.04- (99.1%) and 1.44-log10 (96.4%) colony forming unit, respectively. Altogether, these results suggest that the combination of posaconazole with the HIV protease inhibitors warrants further investigation as a new therapeutic regimen for the treatment of C. auris infections.

Applied physiologically-based pharmacokinetic modeling to assess uridine diphosphate-glucuronosyltransferase-mediated drug-drug interactions for Vericiguat.

Vericiguat (Verquvo; US: Merck, other countries: Bayer) is a novel drug for the treatment of chronic heart failure. Preclinical studies have demonstrated that the primary route of metabolism for vericiguat is glucuronidation, mainly catalyzed by uridine diphosphate-glucuronosyltransferase (UGT)1A9 and to a lesser extent UGT1A1. Whereas a drug-drug interaction (DDI) study of the UGT1A9 inhibitor mefenamic acid showed a 20% exposure increase, the effect of UGT1A1 inhibitors has not been assessed clinically. This modeling study describes a physiologically-based pharmacokinetic (PBPK) approach to complement the clinical DDI liability assessment and support prescription labeling. A PBPK model of vericiguat was developed based on in vitro and clinical data, verified against data from the mefenamic acid DDI study, and applied to assess the UGT1A1 DDI liability by running an in silico DDI study with the UGT1A1 inhibitor atazanavir. A minor effect with an area under the plasma concentration-time curve (AUC) ratio of 1.12 and a peak plasma concentration ratio of 1.04 was predicted, which indicates that there is no clinically relevant DDI interaction anticipated. Additionally, the effect of potential genetic polymorphisms of UGT1A1 and UGT1A9 was evaluated, which showed that an average modest increase of up to 1.7-fold in AUC may be expected in the case of concomitantly reduced UGT1A1 and UGT1A9 activity for subpopulations expressing non-wild-type variants for both isoforms. This study is a first cornerstone to qualify the PK-Sim platform for use of UGT-mediated DDI predictions, including PBPK models of perpetrators, such as mefenamic acid and atazanavir, and sensitive UGT substrates, such as dapagliflozin and raltegravir.

Synthetic and Clinical Perspectives of Evotaz: An Overview.

Viruses cause a variety of diseases in the human body. Antiviral agents are used to prevent the production of disease-causing viruses. These agents obstruct and kill the virus's translation and replication. Because viruses share the metabolic processes of the majority of host cells, finding targeted medicines for the virus is difficult. In the ongoing search for better antiviral agents, the USFDA approved EVOTAZ, a new drug discovered for the treatment of Human Immunodeficiency Virus (HIV). It is a once-daily (OD) fixed-dose combination of Cobicistat, a cytochrome P450 (CYP) enzyme inhibitor, and Atazanavir, a protease inhibitor. The combination drug was created in such a way that it can inhibit both CYP enzymes and proteases at the same time, resulting in the virus's death. The drug is not effective in children under the age of 18; however, it is still being studied for various parameters. This review article focuses on EVOTAZ's preclinical and clinical aspects, as well as its efficacy and safety profiles.

Modern antiretroviral regimens in pregnant women: virologic outcomes and durability.

OBJECTIVES: Data are lacking on the virologic efficacy and durability of modern antiretroviral treatment (ART) regimens during pregnancy. We compared virologic outcomes at delivery among women receiving dolutegravir versus other ART and the rate of change of the initial pregnancy regimen. DESIGN: Single-site retrospective cohort between 2009 and 2019. METHODS: We used univariable and multivariable generalized estimating equations to model the relationship between the maternal ART anchor and the proportion of women with a detectable viral load (greater than or equal to 20 HIV RNA copies/mL of plasma) closest to delivery (suboptimal virologic control) and with a detectable viral load at any time in the third trimester. We also compared changes in ART during pregnancy. RESULTS: We evaluated 230 pregnancies in 173 mothers. Rates of optimal virologic control at delivery did not significantly differ in mothers who received dolutegravir (93.1%), rilpivirine (92.1%), boosted darunavir (82.6%), or efavirenz (76.9%) but were significantly lower among mothers receiving atazanavir (49.0%) or lopinavir (40.9%). The odds of having a detectable viral load at any time in the third trimester was also higher for atazanavir and lopinavir. Raltegravir, elvitegravir, or bictegravir were used in less than 10 mothers at delivery, which precluded statistical analyses. The frequency of change in ART was significantly higher in mothers who initially received elvitegravir (68%) or efavirenz (47%) than dolutegravir (18%). CONCLUSION: Dolutegravir-containing, rilpivirine-containing, and boosted darunavir-containing regimens conferred excellent virologic control in pregnancy. Atazanavir and lopinavir, elvitegravir, and efavirenz were associated with either high rates of virologic failure or regimen change during pregnancy.

Eficácia da ivermectina e atazanavir no tempo de recuperação dos sintomas de covid-19: uma coorte prospectiva / Effectiveness of ivermectin and atazanavir on time to resolution from covid-19 symptoms: a prospective cohort / Eficacia de ivermectina y atazanavir en el tiempo hasta lá resolución de los síntomas de covid-19: una cohorte prospectiva

Objetivo: avaliar a eficácia da Ivermectina e do Atazanavir em comparação com placebo no tempo de resolução dos sintomas e no tempo de duração da doença por COVID-19. Método: estudo observacional, de coorte prospectivo, longitudinal, descritivo e analítico com pacientes sintomáticos ambulatoriais, acompanhados por 06 meses em duas Unidades Básicas de Saúde para atendimento de COVID-19 em Teresina- Piauí, Brasil, no período de novembro a abril de 2021 identificados por amostragem aleatória 1:1:1. Foram realizados exames Reverse transcription polymerase chain reaction (RT-PCR) para confirmação laboratorial da suspeita de infecção pelo novo coronavírus e avaliação sociodemográfica e clínica. Resultados: dos 87 pacientes randomizados, 62,1% (n=54) eram do sexo masculino, com média de idade de 35,1 anos, possuíam companheira (53,9%), baixa renda (50,6%), eutróficos (40,7%) e sem comorbidades de saúde (78,2%). Não houve diferença entre o tempo médio para resolução dos sintomas, que foi de 21 dias (IQR, 8-30) no grupo atazanavir, 30 dias (IQR, 5-90) no grupo ivermectina em comparação com 14 dias (IQR, 9-21) no grupo controle. No dia 180, houve resolução dos sintomas em 100% no grupo placebo, 93,9% no grupo atazanavir e 95% no grupo ivermectina. A duração mediana da doença foi de 08 dias em todos os braços do estudo. Conclusão: o tratamento com atazanavir (6 dias) e ivermectina (3 dias) não reduziu o tempo de resolução dos sintomas e nem o tempo de duração da doença entre os pacientes ambulatoriais com COVID-19 leve em comparação com o grupo placebo. Os resultados não suportam o uso de ivermectina e atazanavir para tratamento de COVID-19 leve a moderado.

Objective: to evaluate the effectiveness of Ivermectin and Atazanavir compared to placebo in the time to resolution of symptoms and duration of illness due to COVID-19. Method: observational, prospective, longitudinal, descriptive and analytical cohort study with symptomatic outpatients, followed for 06 months in two Basic Health Units for COVID-19 care in Teresina-Piauí, Brazil, from November to April 2021 identified by 1:1:1 random sampling. Reverse transcription polymerase chain reaction (RT-PCR) tests were performed for laboratory confirmation of suspected infection with the new coronavirus and sociodemographic and clinical evaluation. Results: of the 87 randomized patients, 62.1% (n=54) were male, with a mean age of 35.1 years, had a partner (53.9%), low income (50.6%), eutrophic (40.7%) and without health comorbidities (78.2%). There was no difference between the median time to resolution of symptoms, which was 21 days (IQR, 8-30) in the atazanavir group, 30 days (IQR, 5- 90) in the ivermectin group compared with 14 days (IQR, 9- 21) in the control group. At day 180, there was resolution of symptoms in 100% in the placebo group, 93.9% in the atazanavir group, and 95% in the ivermectin group. The median duration of illness was 8 days in all study arms. Conclusion: Treatment with atazanavir (6 days) and ivermectin (3 days) did not reduce the time to symptom resolution or the duration of illness among outpatients with mild COVID-19 compared to the placebo group. The results do not support the use of ivermectin and atazanavir for the treatment of mild to moderate COVID-19.

Objetivo: evaluar la efectividad de Ivermectina y Atazanavir en comparación con placebo en el tiempo de resolución de los síntomas y duración de la enfermedad por COVID-19. Método: estudio de cohorte observacional, prospectivo, longitudinal, descriptivo y analítico con pacientes ambulatorios sintomáticos, seguidos durante 06 meses en dos Unidades Básicas de Salud para atención de COVID-19 en Teresina-Piauí, Brasil, de noviembre a abril de 2021 identificados por 1:1:1 muestreo aleatorio. Se realizaron pruebas de reacción en cadena de la polimerasa con transcriptasa inversa (RT-PCR) para confirmación de laboratorio de sospecha de infección por el nuevo coronavirus y evaluación sociodemográfica y clínica. Resultados: de los 87 pacientes aleatorizados, 62,1% (n=54) eran del sexo masculino, con una edad media de 35,1 años, tenían pareja (53,9%), bajos ingresos (50,6%), eutróficos (40,7%) y sin comorbilidades de salud (78,2%). No hubo diferencia entre la mediana de tiempo hasta la resolución de los síntomas, que fue de 21 días (RIC, 8-30) en el grupo de atazanavir, 30 días (RIC, 5- 90) en el grupo de ivermectina en comparación con 14 días (RIC, 9 - 21) en el grupo control. En el día 180, hubo una resolución de los síntomas del 100 % en el grupo de placebo, del 93,9 % en el grupo de atazanavir y del 95 % en el grupo de ivermectina. La mediana de duración de la enfermedad fue de 8 días en todos los brazos del estudio. Conclusión: El tratamiento con atazanavir (6 días) e ivermectina (3 días) no redujo el tiempo de resolución de los síntomas ni la duración de la enfermedad entre los pacientes ambulatorios con COVID-19 leve en comparación con el grupo placebo. Los resultados no respaldan el uso de ivermectina y atazanavir para el tratamiento de la COVID-19 de leve a moderada.

In situ gastric floating gel of atazanavir sulphate for sustained release: formulation, optimization and evaluation.

Aim: Atazanavir sulphate belongs to BCS class II drug, its oral bioavailability is limited due to its rapid first-pass metabolism and P-gp efflux. Materials & methods: The in situ floating gel using the complexed drug was prepared by ion gelation method and optimized the formulation as per 32 full factorial design. Results: Floating lag time of optimized formulation was found to be 18 s and percentage drug release of 94.18 ± 0.18 % at the end of 16 h. The concentration of gelling polymer affects drug release and a floating lag time and vice versa. Conclusion: In situ floating gel of atazanavir sulphate was found promising to sustain drug release due to an increased gastric residence time, which leads to enhanced potential therapy.

In our study, we wanted to create a gel for a medicine called atazanavir sulphate. This gel can float in the stomach for a long time and slowly release the medicine. We mixed atazanavir sulphate with something called ß-cyclodextrin, and this mixture made the medicine dissolve better in water. We used this mixture to make our floating gel, which can stay in the stomach without sinking. Our gel can make the medicine work better because it dissolves well and stays in the stomach for a long time. This means the medicine can help people for a longer period.

Evaluation of the efficacy and safety of oral N-acetylcysteine in patients with COVID-19 receiving the routine antiviral and hydroxychloroquine protocol: A randomized controlled clinical trial.

BACKGROUND: The current absence of gold-standard or all-aspect favorable therapies for COVID-19 renders a focus on multipotential drugs proposed to prevent or treat this infection or ameliorate its signs and symptoms vitally important. The present well-designed randomized controlled trial (RCT) sought to evaluate the efficacy and safety of N-acetylcysteine (NAC) as adjuvant therapy for 60 hospitalized Iranian patients with COVID-19. METHODS: Two 30-person diets, comprising 15 single diets of Kaletra (lopinavir/ritonavir) + hydroxychloroquine (HCQ) with/without NAC (600 mg TDS) and atazanavir/ritonavir + HCQ with/without NAC (600 mg TDS), were administered in the study. RESULTS: At the end of the study, a further decrease in C-reactive protein was observed in the NAC group (P = 0.008), and no death occurred in the atazanavir/ritonavir + HCQ + NAC group, showing that the combination of these drugs may reduce mortality. The atazanavir/ritonavir + HCQ and atazanavir/ritonavir + NAC groups exhibited the highest O2 saturation at the end of the study and a significant rise in O2 saturation following intervention commencement, including NAC (P > 0.05). Accordingly, oral or intravenous NAC, if indicated, may enhance O2 saturation, blunt the inflammation trend (by reducing C-reactive protein), and lower mortality in hospitalized patients with COVID-19. CONCLUSION: The NAC could be more effective as prophylactic or adjuvant therapy in stable non-severe cases of COVID-19 with a particularly positive role in the augmentation of O2 saturation and faster reduction of the CRP level and inflammation or could be effective for better controlling of COVID-19 or its therapy-related side effects.

Evaluating variations in bilirubin glucuronidation activity by protease inhibitors in canine and human primary hepatocytes cultured in a 3D culture system.

Bilirubin is excreted into the bile from hepatocytes, mainly as monoglucuronosyl and bisglucuronosyl conjugates, reflecting bilirubin glucuronidation activity. However, there is limited information on the in vitro evaluation of liver cell lines or primary hepatocytes. This study aimed to investigate variations in the bilirubin metabolic function of canine and human hepatocyte spheroids formed in a three-dimensional (3D) culture system indicated by the formation of bilirubin glucuronides when protease inhibitors such as atazanavir, indinavir, ritonavir, and nelfinavir were treated with bilirubin. The culture supernatant was collected for bilirubin glucuronidation assessment and the cells were used to evaluate viability. On day 8 of culture, both canine and human hepatocyte spheroids showed high albumin secretion and distinct spheroid formation, and their bilirubin glucuronidation activities were evaluated considering cell viability. Treatment with atazanavir and ritonavir remarkably inhibited bilirubin glucuronide formation, wherein atazanavir showed the highest inhibition, particularly in human hepatocyte spheroids. These results may reflect the effects on cellular uptake of bilirubin and its intracellular metabolic function. Thus, primary hepatocytes cultured in a 3D culture system may be a useful in vitro system for the comprehensive evaluation of bilirubin metabolic function and risk assessment in bilirubin metabolic disorders for drug development.

Biterapia con atazanavir/ritonavir más raltegravir versus terapia triple en segunda línea: Ensayo ARTE / ATV/r+RAL (DT) after failure with NNRTI

Antecedentes: La terapia dual ha surgido como un nuevo concepto para el tratamiento del VIH. Este estudio tenía como objetivo comparar un régimen dual basado en ATV/r + RAL (TD) frente a estándar de tres drogas con ATV/r + TDF/FTC (TT) luego del fracaso de un primer esquema ba-sado en INNTR.ClinicalTrials.gov, Número: NCT01829802.Método: Estudio piloto abierto, multicéntrico y aleatoriza-do. Resultado primario: proporción de sujetos con ARN del VIH-1 menor a 50 copias/mL en semana 48 (S48). Resulta-dos secundarios: discontinuaciones asociadas a eventos adversos (EA), tiempo transcurrido hasta la supresión viral, desarrollo de mutaciones de resistencia a la integrasa y proteasa, cambio en recuento de CD4. Resultados: De los 57 participantes seleccionados, 34 fue-ron asignados aleatoriamente para recibir: TD (n: 18) o TT (n: 16). En semana 48, 67% (n: 12/18) en TD tuvo respues-ta virológica y 88% (n: 14/16) en rama según el análisis FDA, intención de tratamiento/expuestos (p = NS) y 73% (TD) y 93% (TT) según análisis por protocolo (p = NS). El cambio de CD4 entre basal - S48: +119 y +52 células/µL en DT y TT, respectivamente. Cuatro participantes en TD y uno en TT presentaron fracaso virológico en la semana 48. Un participante desarrolló una mutación de resistencia a integrasa (155H).Conclusión: ATV/r+RAL como terapia dual de segunda línea mostró una tendencia al fracaso virológico más frecuente, en comparación con TT, aunque el estudio piloto no tenía potencia para demostrar esta diferencia. Este estudio está registrado en ClinicalTrials.gov, Número: NCT01829802

Background: Dual therapy has emerged as a novel concept for HIV treatment. This study was aimed at comparing a nucleoside-sparing dual regimen consisting of ATV/r + RAL (DT) vs standard therapy of ATV/r + TDF/FTC (TT) among individuals failing first NNRTI-containing treatment.Methods: Randomized multicenter open-label pilot study. Primary outcome: proportion of subjects with plasma HIV-1 RNA below the limit of detection (<50 copies/mL) at 48 weeks (W48). Secondary outcomes: proportion of discontinuation due to adverse events (AEs), time until viral suppression, time until loss of virological response, development of integrase resistance mutations, and absolute change in CD4 counts. The primary outcome was analyzed using the FDA snapshot analysis.Results: Out of 57 participants screened, 34 were randomized to receive: DT (n: 18) or TT (n: 16). At W48, virological response was achieved in 67% (n: 12/18) of participants receiving DT and 88% (n: 14/16) receiving TT by FDA snapshot analysis (p = NS) and 73% and 93% by per-protocol analysis (p = NS). CD4 cell count median change from baseline to W48 was +119 and + 52 cell/µL in DT and TT, respectively. Four participants receiving DT and one TT presented virological failure at W48, with low pVL. One participant developed an integrase resistance mutation (155H) and suppressed later on TT.Conclusion: ATV/r+RAL as second-line therapy showed a trend to more frequent virological failure, compared to TT, although the study was unpowered to prove this difference. No major differences were seen in tolerance or toxicity.This study is registered with ClinicalTrials.gov, Number: NCT01829802

Kinetic Barriers to Disproportionation of Salts of Weakly Basic Drugs.

Disproportionation is a major issue in formulations containing salts of weakly basic drugs. Despite considerable interest in risk assessment approaches for disproportionation, the prediction of salt-to-base conversion remains challenging. Recent studies have highlighted several confounding factors other than pHmax that appear to play an important role in salt disproportionation and have suggested that kinetic barriers need to be considered in addition to the thermodynamic driving force when assessing the risk of a salt to undergo conversion to parent free base. Herein, we describe the concurrent application of in situ Raman spectroscopy and pH monitoring to investigate the disproportionation kinetics of three model salts, pioglitazone hydrochloride, sorafenib tosylate, and atazanavir sulfate, in aqueous slurries. We found that even for favorable thermodynamic conditions (i.e., pH ≫ pHmax), disproportionation kinetics of the salts were very different despite each system having a similar pHmax. The importance of free base nucleation kinetics was highlighted by the observation that the disproportionation conversion time in the slurries showed the same trend as the free base nucleation induction time. Pioglitazone hydrochloride, with a free base induction time of <1 min, rapidly converted to the free base in slurry experiments. In contrast, atazanavir sulfate, where the free base induction time was much longer, took several hours to undergo disproportionation in the slurry for pH ≫ pHmax. Additionally, we altered an established thermodynamically based modeling framework to account for kinetic effects (representing the nucleation kinetic barrier) to estimate the solid-state stability of salt formulations. In conclusion, a solution-based thermodynamic model is mechanistically appropriate to predict salt disproportionation in a solid-state formulation, when kinetic barriers are also taken into consideration.

First Pharmacokinetic Data of Tenofovir Alafenamide Fumarate and Tenofovir With Dolutegravir or Boosted Protease Inhibitors in African Children: A Substudy of the CHAPAS-4 Trial.

BACKGROUND: We evaluated the pharmacokinetics of tenofovir alafenamide fumarate (TAF) and tenofovir in a subset of African children enrolled in the CHAPAS-4 trial. METHODS: Children aged 3-15 years with human immunodeficiency virus infection failing first-line antiretroviral therapy were randomized to emtricitabine/TAF versus standard-of-care nucleoside reverse transcriptase inhibitor combination, plus dolutegravir, atazanavir/ritonavir, darunavir/ritonavir, or lopinavir/ritonavir. Daily emtricitabine/TAF was dosed according to World Health Organization (WHO)-recommended weight bands: 120/15 mg in children weighing 14 to <25 kg and 200/25 mg in those weighing ≥25 kg. At steady state, 8-9 blood samples were taken to construct pharmacokinetic curves. Geometric mean (GM) area under the concentration-time curve (AUC) and the maximum concentration (Cmax) were calculated for TAF and tenofovir and compared to reference exposures in adults. RESULTS: Pharmacokinetic results from 104 children taking TAF were analyzed. GM (coefficient of variation [CV%]) TAF AUClast when combined with dolutegravir (n = 18), darunavir/ritonavir (n = 34), or lopinavir/ritonavir (n = 20) were 284.5 (79), 232.0 (61), and 210.2 (98) ng*hour/mL, respectively, and were comparable to adult reference values. When combined with atazanavir/ritonavir (n = 32), TAF AUClast increased to 511.4 (68) ng*hour/mL. For each combination, tenofovir GM (CV%) AUCtau and Cmax remained below reference values in adults taking 25 mg TAF with a boosted protease inhibitors. CONCLUSIONS: In children, TAF combined with boosted PIs or dolutegravir and dosed according to WHO-recommended weight bands provides TAF and tenofovir concentrations previously demonstrated to be well tolerated and effective in adults. These data provide the first evidence for use of these combinations in African children. CLINICAL TRIALS REGISTRATION: ISRCTN22964075.

Atazanavir-induced unconjugated hyperbilirubinemia prevents vascular hyporeactivity during experimental human endotoxemia.

Objective: Inflammation-induced free radical release is important in the pathogenesis of several diseases, including atherosclerosis and sepsis. Heme oxygenase (HO) breaks down heme into carbon monoxide, iron, and biliverdin. Biliverdin IXα is directly converted to bilirubin by biliverdin reductase. Unconjugated bilirubin is a powerful antioxidant, and elevated levels have beneficial effects in preclinical models and human cardiovascular disease. However, its impact during acute inflammation in humans is unknown. In the present study, we investigated the impact of atazanavir-induced (unconjugated) hyperbilirubinemia on antioxidant capacity, inflammation, and vascular dysfunction in human experimental endotoxemia. Approach and results: Following double-blinded four-day treatment with atazanavir 2dd300 mg (or placebo), twenty healthy male volunteers received 2 ng/kg Escherichia coli lipopolysaccharide intravenously. Blood was drawn to determine the bilirubin levels, antioxidant capacity, and cytokine response. It was demonstrated that following atazanavir treatment, total bilirubin concentrations increased to maximum values of 4.67 (95%CI 3.91-5.59) compared to 0.82 (95%CI 0.64-1.07) mg/dL in the control group (p<0.01). Furthermore, the anti-oxidant capacity, as measured by the ferric-reducing ability of plasma (FRAP), was significantly increased with 36% in hyperbilirubinemia subjects (p<0.0001), and FRAP concentrations correlated strongly to bilirubin concentrations (R2 = 0.77, p<0.001). Hyperbilirubinemia attenuated the release of interleukin-10 from 377 (95%CI 233-609) to 219 (95%CI 152-318) pg/mL (p=0.01), whereas the release of pro-inflammatory cytokines remained unaltered. In vitro, in the absence of hyperbilirubinemia, atazanavir did not influence lipopolysaccharide-induced cytokine release in a whole blood assay. Vascular function was assessed using forearm venous occlusion plethysmography after intra-arterial infusion of acetylcholine and nitroglycerin. Hyperbilirubinemia completely prevented the LPS-associated blunted vascular response to acetylcholine and nitroglycerin. Conclusions: Atazanavir-induced hyperbilirubinemia increases antioxidant capacity, attenuates interleukin-10 release, and prevents vascular hyporesponsiveness during human systemic inflammation elicited by experimental endotoxemia. Clinical trial registration: http://clinicaltrials.gov, identifier NCT00916448.

Spherical crystal agglomeration technique for improved flow properties and oral bioavailability of atazanavir sulphate.

Aim: The current research focused on formulation of spherical crystal agglomerates (SCA) of atazanavir sulphate for improving flow property and solubility. Materials & methods: SCA were formulated by quasi-emulsification solvent diffusion. Methanol, water and dichloromethane were employed as a good solvent, bad solvent and bridging liquid respectively. Results & conclusion: SCA with improved solubility and micromeritic properties were directly compressed into a tablet. The SCA tablets had higher dissolution rates compared with plain drug and marketed product. In vivo pharmacokinetic studies revealed higher Cmax and AUC0-t of the SCA than marketed product with relative bioavailability of 1.74. The formulation was stable for more than 3 months, with insignificant difference in % drug content and % drug dissolution.

Atazanavir sulphate is a drug used for treatment of AIDS in which the patients are infected with HIV. Presently, it is available as a capsule. The amount of the drug reaching the blood after oral delivery is less due to the poor solubility of the drug. Compared with capsules, tablets are more preferred dosage forms due to its ease of manufacturing and tamper proof nature. In the present research work, we have developed a tablet formulation of the drug, which has improved solubility. The higher solubility leads to greater absorption after oral delivery. Thus the formulation is beneficial to the patients as the dose can be reduced and the treatment can be made more economic.

A Combination of Novel HIV-1 Protease Inhibitor and Cytochrome P450 (CYP) Enzyme Inhibitor to Explore the Future Prospective of Antiviral Agents: Evotaz.

Viruses belong to the class of micro-organisms that are well known for causing infections in the human body. Antiviral medications are given out to prevent the spread of disease-causing viruses. When the viruses are actively reproducing, these agents have their greatest impact. It is particularly challenging to develop virus-specific medications since viruses share the majority of the metabolic functions of the host cell. In the continuous search for better antiviral agents, the United States Food and Drug Administration (USFDA) approved a new drug named Evotaz on January 29, 2015 for the treatment of human immunodeficiency virus (HIV). Evotaz is a combined once-daily fixed drug, containing Atazanavir, an HIV protease inhibitor, and cobicistat, an inhibitor of the human liver cytochrome P450 (CYP) enzyme. The medication is created such that it can kill viruses by concurrently inhibiting protease and CYP enzymes. The medicine is still being studied for a number of criteria, but its usefulness in children under the age of 12 is currently unknown. The preclinical and clinical characteristics of Evotaz, as well as its safety and efficacy profiles and a comparison of the novel drug with antiviral medications presently available in the market, are the main topics of this review paper.

Supersaturating lipid-based solid dispersion of atazanavir provides enhanced solubilization and supersaturation in the digestive aqueous phase.

Understanding and controlling the drug solubilization in digestive environment is of great importance in the design of lipid based solid dispersion (LBSD) for oral delivery of poorly aqueous soluble drugs. In the current study we determined the extent of drug solubilization and supersaturation of supersaturating lipid based solid dispersion which is governed by formulation variables like drug payload, lipid composition, solid carrier properties and lipid to solid carrier ratio. Initially, the impact of lipid chain length and drug payload on drug solubilization in lipid preconcentrate and dispersibility were evaluated to design liquid LbF of the model antiretroviral drug, atazanavir. The temperature induced supersaturation method enhanced the drug payload in medium chain triglyceride formulation at 60 °C. Further, the selected liquid supersaturated LbF was transformed into solid state LbF by employing different solid carriers including silica (Neusilin® US2 and Aerosil® 200), clay (Montmorillonite and Bentonite) and polymer (HPMC-AS and Kollidon® CL-M). The fabricated LBSDs were evaluated for solid state characterization to identify the physical nature of drug. In vitro digestion studies were conducted using pH-stat lipolysis method to assess the supersaturation propensity in aqueous digestive phase. Results revealed that LBSDs with silica and polymer carriers showed maximum drug solubilization throughout experiment compared to liquid LbF. The ionic interaction between drug-clay particles significantly reduced the ATZ partitioning from clay based LBSDs. LBSDs with dual purpose solid carrier like HPMC-AS and Neusilin® US2 offers the potential to improve drug solubilization of ATZ for physiologically relevant time. Lastly, we conclude that evaluation of formulation variables is crucial to achieve optimal performance of supersaturating LBSD.

Atazanavir Resensitizes Candida auris to Azoles.

Candida auris represents an urgent health threat. Here, we identified atazanavir as a potent drug capable of resensitizing C. auris clinical isolates to the activity of azole antifungals. Atazanavir was able to significantly inhibit the efflux pumps, glucose transport, and ATP synthesis of all tested isolates of C. auris. In addition, the combination of itraconazole with atazanavir-ritonavir significantly reduced the burden of azole-resistant C. auris in murine kidneys by 1.3 log10 (95%), compared to itraconazole alone.