HIV-1 Integrase T218I/S Polymorphisms Do Not Reduce HIV-1 Integrase Inhibitors' Phenotypic Susceptibility.

The recently Food and Drug Administration (FDA)-approved cabotegravir (CAB) has demonstrated efficacy as an antiretroviral agent for HIV treatment and prevention, becoming an important tool to stop the epidemic in the United States of America (USA). However, the effectiveness of CAB can be compromised by the presence of specific integrase natural polymorphisms, including T97A, L74M, M50I, S119P, and E157Q, particularly when coupled with the primary drug-resistance mutations G140S and Q148H. CAB's recent approval as a pre-exposure prophylaxis (PrEP) may increase the number of individuals taking CAB, which, at the same time, could increase the number of epidemiological implications. In this context, where resistance mutations, natural polymorphisms, and the lack of drug-susceptibility studies prevail, it becomes imperative to comprehensively investigate concerns related to the use of CAB. We used molecular and cell-based assays to assess the impact of T218I and T218S in the context of major resistance mutations G140S/Q148H on infectivity, integration, and resistance to CAB. Our findings revealed that T218I and T218S, either individually or in combination with G140S/Q148H, did not significantly affect infectivity, integration, or resistance to CAB. Notably, these polymorphisms also exhibited neutrality concerning other widely used integrase inhibitors, namely raltegravir, elvitegravir, and dolutegravir. Thus, our study suggests that the T218I and T218S natural polymorphisms are unlikely to undermine the effectiveness of CAB as a treatment and PrEP strategy.

Marcadores lipídicos en los pacientes con VIH/sida en tratamiento con inhibidores de la proteasa

Introducción: Las enfermedades cardiovasculares constituyen la principal causa de morbimortalidad a escala mundial. Otra enfermedad con impacto significativo en los sistemas de salud pública es el VIH/sida. Los pacientes infectados con el virus de la inmunodeficiencia humana, tienen mayor riesgo de desarrollar enfermedades cardiovasculares. Posterior al tratamiento antirretroviral ha disminuido la incidencia de enfermedades oportunistas asociadas al VIH/sida, y se ha elevado la incidencia de enfermedades asociadas al envejecimiento, como la enfermedad cardiovascular. El uso de antirretrovirales inhibidores de la proteasa se asocia a hiperlipidemia y, por consiguiente, al aumento de complicaciones cardiovasculares. Objetivo: Determinar los marcadores lipídicos en pacientes con VIH/sida en tratamiento con inhibidores de la proteasa. Materiales y métodos: Se realizó un estudio observacional, analítico, transversal en los pacientes con VIH/sida de la provincia de Matanzas, durante el período comprendido entre marzo y agosto de 2020, en el Laboratorio Clínico del Hospital Universitario Clínico Quirúrgico Comandante Faustino Pérez Hernández. Resultados: Se evaluaron los marcadores lipídicos como factor de riesgo cardiovascular asociado al tratamiento antirretroviral, siendo los triglicéridos el de mayor incidencia. Conclusiones: Se identificaron los marcadores lipídicos como factores de riesgo cardiovascular, en este caso la hipertrigliceridemia.

Introduction: Cardiovascular diseases are the main risk of morbidity and mortality worldwide. Another disease with significant impact on public health systems is HIV/AIDS. Patients infected with the human immunodeficiency virus have a higher risk of developing cardiovascular diseases. After antiretroviral treatment, the incidence of opportunistic diseases associated with HIV/AIDS has decreased and the incidence of diseases associated with aging such as cardiovascular disease has increased. The use of protease inhibitor antiretroviral drugs is associated with hyperlipidemia and a consequent increase in cardiovascular complications. Objective: To determine lipid markers in patients with HIV/AIDS undergoing treatment with protease inhibitors. Materials and method: An observational, analytical, cross-sectional study was carried out in patients with HIV/AIDS from the province of Matanzas during the period from March to August 2020, in the Clinical Laboratory of the Provincial Teaching Clinical Surgical Hospital Faustino Pérez Hernandez. Results: Lipid markers were evaluated as cardiovascular risk factor associated with antiretroviral treatment, with triglycerides being the one of highest incidence. Conclusions: Lipid markers were identified as cardiovascular risk factors; in this case hypertriglyceridemia.

Resistencia genotípica del HIV a los antirretrovirales en niños de Argentina entre 2006 y 2021 / HIV genotypic drug resistance to antiretrovirals in children in Argentina between 2006 and 2021

Introducción: La resistencia del HIV a los antirretrovirales (ARVs) es una de las principales causas de fallo terapéutico en niños, niñas y adolescentes que conviven con el virus. Desde el año 2006, el Laboratorio de Biología Celular y Retrovirus del Hospital Garrahan realiza el estudio genotípico de resistencia (ER) del HIV-1 a los ARVs a fin de identificar mutaciones que disminuyen la susceptibilidad del virus a los fármacos que componen el tratamiento ARV. Objetivos: El objetivo del trabajo fue estudiar el tipo y frecuencia de resistencia del HIV a los ARVs, a través de un análisis de 371 ER realizados entre los años 2006 y 2021 en niños, niñas y adolescentes con HIV-1 adquirido por transmisión vertical y con solicitud médica de ER por presentar fallo terapéutico. Resultados: Entre los años 2006 y 2013 la proporción de casos con resistencia a al menos una clase de fármaco ARV fue mayor al 90%, sugiriendo una asociación directa entre el fallo virológico y la disminución en la susceptibilidad del HIV-1 a uno o más componentes del TARV. A partir del año 2012, se observa una disminución progresiva del nivel de resistencia de HIV-1, llegando al 50% en 2021 (p<0.0001). La frecuencia de mutaciones de resistencia fue diferente para cada una de las clases de ARVs. Mientras que la resistencia a INNTR no sufrió cambios significativos a lo largo del período de estudio, oscilando entre 27% y 75%. La proporción de mutaciones a IPs en pacientes con fallo virológico disminuyó de 87% en 2006 a 17% en 2021 y para los INTR, disminuyó de 79% en 2006 a 45% en 2021. Conclusión: El nivel de resistencia a los ARVs ha disminuido de manera sustancial a lo largo de los últimos 16 años, probablemente por el uso de nuevos fármacos ARV con alta potencia que posibilitaron la intensificación de los tratamientos ARV y la implementación de criterios de fallo terapéutico más estrictos tanto a nivel clínico como virológico (AU)

Introduction: HIV resistance to antiretroviral (ARV) drugs is one of the main causes of therapeutic failure in children and adolescents living with the virus. Since 2006, the Cell Biology and Retrovirus Laboratory of the Garrahan Hospital has been performing the genotypic study of HIV-1 resistance to ARV drugs in order to identify mutations that reduce the susceptibility of the virus to the drugs that constitute ARV treatment. Objectives: The aim of this study was to assess the type and frequency of HIV resistance to ARV drugs through an analysis of 371 genotype studies performed between 2006 and 2021 in children and adolescents with HIV-1 acquired through motherto-child transmission and with medical request for genotype study due to therapeutic failure. Results: Between 2006 and 2013, the proportion of cases with resistance to at least one ARV drug class was greater than 90%, suggesting a direct association between virologic failure and decreased susceptibility of HIV-1 to one or more components of ART. From 2012 onwards, a progressive decrease in the level of HIV-1 resistance was observed, reaching 50% in 2021 (p<0.0001). The frequency of resistant mutations was different for each of the ARV classes, while resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs) did not change significantly over the study period, ranging from 27% to 75%. The proportion of drug-resistant mutations to protease inhibitors (PI) in patients with virologic failure decreased from 87% in 2006 to 17% in 2021 and for NNRTIs from 79% in 2006 to 45% in 2021. Conclusion: The level of resistance to ARV drugs has decreased substantially over the last 16 years, probably due to the use of new ARV drugs with high potency that allowed the intensification of ARV treatments and the implementation of stricter criteria for therapeutic failure both clinically and virologically (AU)

Adherence to antiretroviral therapy among women living with HIV/AIDS in the interior of the Brazilian state of Pará: cross-sectional study

ABSTRACT BACKGROUND: High prevalence of human immunodeficiency virus (HIV) infection and occurrence of drug-resistant strains have been recorded in northern Brazil. Abandonment of treatment and insufficient and inadequate adherence to antiretroviral therapy (ART) among people living with HIV/AIDS (PLWHA) have been recorded in the metropolitan area of Belém, the capital of the state of Pará. OBJECTIVES: To identify the sociodemographic profile and level of adherence to ART among women seen at a referral unit in the interior of Pará, northern Brazil. DESIGN AND SETTING: Cross-sectional study at a referral unit for care for PLWHA. METHODS: We included 86 women living with HIV/AIDS (WLWHA) in the Rio Caeté integrated region, northeastern Pará. Social, demographic and behavioral information, as well as the ART level, were obtained using forms that have been described in the scientific literature. Logistic regression models were used to assess associations of variables with ART. RESULTS: Most WLWHA were single (52.4%), young (47.7%) and heterosexual (97.7%), had low levels of education (63.0%), were unemployed (69.8%), had one sexual partner (75.7%), used condoms (46.7%) and were not using either licit drugs (68.7%) or illicit drugs (89.6%). Their adherence level was classified as insufficient , and only their viral load showed an association with ART. CONCLUSIONS: The participants' low level of education and poor socioeconomic conditions may have been interfering with their adherence to ART. Such influences can be minimized through multiprofessional interventions that take the individuality of women served by the healthcare service into consideration.

Sarcoma de Kaposi oral en paciente seropositivo, fase sintomática avanzada. Presentación de caso / Oral Kaposi Sarcoma, advanced symptomatic phase, in a seropositive patient. Case presentation

RESUMEN Se presentó el caso clínico de un paciente seropositivo, en fase sintomática avanzada. Fue atendido en el Servicio de Medicina Interna del Hospital Clínico Quirúrgico Docente "León Cuervo Rubio", de la ciudad de Pinar del Río, por presentar disnea, astenia, anorexia y pérdida de peso. Al examen oral se constató lesión tumoral de la lengua que dificultaba la masticación y deglución. La biopsia mostró sarcoma de Kaposi asociado al VIH/sida. La evolución tórpida y el estadio tan avanzado de la enfermedad, propiciaron el deceso del paciente (AU).

ABSTRACT The authors presented the clinical case of a seropositive patient, in advanced symptomatic phase. The patient attended the Internal Medicine Service of the Teaching Clinical Surgical Hospital Leon Cuervo Rubio of Pinar del Rio, presenting dyspnea, asthenia, anorexia and weight loss. On the oral examination, a tumor lesion was found making difficult to chew and swallow. A biopsy showed Kaposi sarcoma associated to HIV/AIDS. The torpid evolution and disease's advanced stage propitiated the patient's death (AU).

Development and validation of RP-HPLC method for simultaneous determination of lamivudine, stavudine, and zidovudine in perfusate samples: Application to the Single-Pass Intestinal Perfusion (SPIP) studies

A reversed-phase high performance liquid chromatography (RP-HPLC) method with ultraviolet detection was developed and validated for the simultaneous quantification of antiretroviral drugs lamivudine (3TC), stavudine (d4T), and zidovudine (AZT) in perfusate samples obtained from the Single-Pass Intestinal Perfusion studies. The chromatographic analysis was performed using a Gemini C18 column and didanosine as internal standard (IS). The following parameters were considered for the validation procedure: system suitability, accuracy, precision, linearity and selectivity. The limits of detection were 0.32 µg/mL for 3TC, 0.11 µg/mL for d4T and 0.45 µg/mL for AZT and the limits of quantification were 1.06 µg/mL for 3TC, 0.38 µg/mL for d4T and 1.51 µg/mL for AZT. Repeatability and intermediate precision ranged from 1.05 to 1.31 and 1.50 to 1.87, respectively, and are expressed as percent of relative standard deviation (RSD). Based on these results, the developed and validated RP-HPLC method can be used for simultaneous determination of 3TC, d4T, and AZT in perfusate samples. Furthermore, this method is simple and adequate for measurements of the antiretroviral drugs in the same sample, since those compounds are mostly co-administered. Besides, this work can be used as an initial base for the development of similar methods in the same conditions presented in our study.

Variables psicosociales predictoras de la no adherencia a los antirretrovirales en personas con VIH-SIDA / Predictive Psychosocial Variables of Non-Adherence to Antiretrovirals in People with HIV-AIDS

Resumen Objetivo: El presente estudio tuvo como objetivo evaluar los niveles de adherencia al tratamiento antirretroviral, así como determinar los factores psicológicos predictores de la no adherencia a dicho tratamiento en pacientes con VIH-SIDA. Método: Diseño descriptivo, transversal y correlacional. La muestra estuvo conformada por 25 personas diagnosticadas con VIH-SIDA que asistieron a los servicios integrales de una asociación civil en la ciudad de Guadalajara, México, y que se encontraban bajo tratamiento antirretroviral. Se utilizó el Cuestionario de adherencia al tratamiento para el VIH-SIDA [CAT-VIH] y el Cuestionario de Factores Relacionados con la Adherencia al Tratamiento para el VIH/SIDA (CFR-AT VIH). Se realizaron análisis descriptivos y no paramétricos para la comparación de las variables de estudio, así como sus respectivas correlaciones. Resultados: Solo 60% de los evaluados presentan una adecuada adherencia al tratamiento con antirretrovirales; además se encontraron diferencias significativas entre adherentes y no adherentes en las variables de autoeficacia (Z=-3.196; p=.001); estrés (Z=-2.033; p=.042); y depresión (Z=-2.409; p=.016). Se obtuvieron correlaciones positivas de la adherencia con autoeficacia (r=.750; p=.000) y apoyo social (r=.462; p=.020) y correlaciones negativas con estrés (r=-.543; p=.005) y depresión (r=-.544; p=.005). Conclusiones: A mayores estados de estrés y depresión, menor serán los niveles de adherencia al tratamiento con antirretrovirales; por lo cual estas variables deben ser tomadas en cuenta para el diseño de estrategias de mejora de la adherencia en personas con VIH-SIDA.

Abstract Objective: Objective: The main aim of this study was to evaluate the levels of adherence to antiretrovirals treatment as well as to determine the psychological factors that predict the non-adherence to antiretrovirals in HIV patients who attend a civil association in Guadalajara, México. Method: It was a descriptive, transversal and correlational design. The sample consisted of 25 patients diagnosed with HIV who attended integral services of a Civil Association. The Adherence to Treatment for HIV/AIDS Questionnaire [CAT-HIV] and the Questionnaire of Factors Related to Adherence to Treatment for HIV/AIDS (CFR-AT HIV) were used. Descriptive and nonparametric analyzes were carried out to compare the study variables, as well as their respective correlations, all through the statistical program SPSS v.20. Results: Only 60% of those evaluated showed adequate adherence to antiretrovirals; in addition, significance differences between adherents and non-adherents in the self-efficacy variable (Z = -3.196, p = .001); stress (Z = -2.033, p = .042); and depression (Z = -2.409, p = .016). Positive correlations of adherence were obtained with self-efficacy (r = .750, p = .000) and social support (r = .462, p = .020) and negative correlations with stress (r = - .543; p = .005) and depression (r = -. 544; p = .005). Conclusions: The higher levels of stress and depression, the lower the levels of adherence to antiretroviral treatment; therefore, these variables must be considered in the design of strategies to improve adherence in people with HIV.

Efectividad y seguridad del esquema genérico lamivudina/tenofovir y efavirenz en pacientes con VIH/SIDA naïve: estudio fase IV no aleatorizado, Cali-Colombia 2012-2014 / Effectiveness and safety of generic version of lamivudine/tenofovir and efavirenz in treatment naïve HIV-infected patients: a nonrandomized, open-label, phase IV study in Cali-Colombia, 2012-2014

Resumen Antecedentes: Los estudios clínicos orientados a evaluar la calidad de medicamentos genéricos pueden ser útiles para fortalecer políticas de acceso a terapia anti-retroviral combinada (TARc). Objetivo: Describir la efectividad y seguridad del esquema genérico lamivudina/tenofovir/efavirenz (3TC/TDF/EFV) en pacientes con infección por VIH/SIDA naïve, pertenecientes a un programa de atención integral. Materiales/Métodos: Estudio clínico prospectivo fase IV abierto y sin grupo control. Entre 2012-2014, se incluyeron y siguieron 40 pacientes con infección por VIH/SIDA naïve y con indicación para iniciar tratamiento. Los pacientes fueron tratados con el esquema genérico 3TC/TDF/EFV y fueron seguidos durante 12 meses. El seguimiento incluyó valoración clínica, parámetros inmunovirológicos y de laboratorio, al inicio del tratamiento y a los 3, 6 y 12 meses. Resultados: De los 40 pacientes, 30 (75%) cumplieron los doce meses de tratamiento; de ellos, 80% alcanzó CV indetectable (< 40 copias/mL) y 83,3% CV < 50 copias/mL. Adicionalmente, en el grupo hubo un incremento en la mediana de 173 linfocitos TCD4/mm3. Por su parte, los resultados del hemograma completo, creatininemia y transaminasas hepáticas se conservaron en rangos normales y no generaron cambios del TARc. Los efectos adversos reconocidos para estos medicamentos se presentaron en menos de 10% de los pacientes y no tuvieron implicaciones graves. Conclusiones: En este grupo pequeño de pacientes, el esquema genérico 3TC/TDF/EFV es efectivo y seguro en el tratamiento de pacientes con infección por VIH/SIDA naïve, y su perfil de efectividad y seguridad es similar al del esquema 3TC/TDF/EFV innovador en pacientes con condiciones clínicas similares.

Background: Clinical studies aimed to evaluating the quality of generic drugs may be useful to strengthen policies of access to combined antiretroviral therapy (cART). Aim: To describe the effectiveness and safety of the generic schema lamivudine/tenofovir/efavirenz (3TC/TDF/EFV) in patients with HIV/AIDS naive, belonging to a comprehensive care program. Methods: A nonrandomized, open-label, phase IV study, during 2012 to 2014 naive HIV-infected patients 18 years or older with indication to receive cART were recruited. Patients were treated with generic scheme 3TC/TDF/EFV and were followed-up during 12 months. Clinical, immunological and laboratory parameters were assessed at baseline, 3, 6 and 12 months of treatment. Results: Of the 40 patients, 30 (75%) met the 12 months of treatment; of them, 80% achieved undetectable viral load (< 40 copies/mL) and 83.3% viral load < 50 copies/mL. Additionally, there was a significant increase (173 cells/mm3) in the median for CD4 T lymphocyte count. Moreover, the results of the whole blood count, creatinine and transaminases were preserved in normal ranges and did not generate changes in the cART. Potential side effects of antiretroviral drugs occurred in less than 10% of patients and had no serious implications. Conclusions: In this small group of patients, the generic scheme 3TC/TDF/EFV is effective and safe in the treatment of patients with HIV/AIDS naïve, and its effectiveness and safety profile is similar to show by innovator scheme 3TC/TDF/EFV in patients with similar clinical conditions. Registro Estudio: Registro Público Cubano de Ensayos Clínicos (RPCEC) ID: RPCEC00000134. Registered 20 July 2012.

Prevalence and risk factors of mild chronic renal failure in HIV-infected patients: influence of female gender and antiretroviral therapy

ABSTRACT Background In people living with HIV, much is known about chronic kidney disease, defined as a glomerular filtration rate under 60 mL/min. However, there is scarce data about prevalence and risk factors for milder impairment (60-89 mL/min). Objective The present study aims to assess the influence of sex, antiretroviral therapy, and classical risk factors on the occurrence of mild decreased renal function in a large Spanish cohort of HIV-infected patients. Methods Cross-sectional, single center study, including all adult HIV-1-infected patients under antiretroviral treatment with at least two serum creatinine measures during 2014, describing the occurrence of and the risk factors for mildly decreased renal function (eGFR by CKD-EPI creatinine equation of 60-89 mL/min). Results Among the 4337 patients included, the prevalence rate of mildly reduced renal function was 25%. Independent risk factors for this outcome were age older than 50 years (OR 3.03, 95% CI 2.58-3.55), female sex (OR 1.23, 95% CI 1.02-1.48), baseline hypertension (OR 1.57, 95% CI 1.25-1.97) or dyslipidemia (OR 1.48, 95% CI 1.17-1.87), virologic suppression (OR 1.88, 95% CI 1.39-2.53), and exposure to tenofovir disoproxil-fumarate (OR 1.67, 95% CI 1.33-2.08) or ritonavir-boosted protease-inhibitors (OR 1.19, 95% CI 1.03-1.39). Conclusions Females and patients over 50 seem to be more vulnerable to renal impairment. Potentially modifiable risk factors and exposure to tenofovir disoproxil-fumarate or ritonavir-boosted protease-inhibitors are present even in earlier stages of chronic kidney dysfunction. It remains to be determined whether early interventions including antiretroviral therapy changes (tenofovir alafenamide, cobicistat) or improving comorbidities management will improve the course of chronic kidney disease.

Prevalence and risk factors of mild chronic renal failure in HIV-infected patients: influence of female gender and antiretroviral therapy.

BACKGROUND: In people living with HIV, much is known about chronic kidney disease, defined as a glomerular filtration rate under 60mL/min. However, there is scarce data about prevalence and risk factors for milder impairment (60-89mL/min). OBJECTIVE: The present study aims to assess the influence of sex, antiretroviral therapy, and classical risk factors on the occurrence of mild decreased renal function in a large Spanish cohort of HIV-infected patients. METHODS: Cross-sectional, single center study, including all adult HIV-1-infected patients under antiretroviral treatment with at least two serum creatinine measures during 2014, describing the occurrence of and the risk factors for mildly decreased renal function (eGFR by CKD-EPI creatinine equation of 60-89mL/min). RESULTS: Among the 4337 patients included, the prevalence rate of mildly reduced renal function was 25%. Independent risk factors for this outcome were age older than 50 years (OR 3.03, 95% CI 2.58-3.55), female sex (OR 1.23, 95% CI 1.02-1.48), baseline hypertension (OR 1.57, 95% CI 1.25-1.97) or dyslipidemia (OR 1.48, 95% CI 1.17-1.87), virologic suppression (OR 1.88, 95% CI 1.39-2.53), and exposure to tenofovir disoproxil-fumarate (OR 1.67, 95% CI 1.33-2.08) or ritonavir-boosted protease-inhibitors (OR 1.19, 95% CI 1.03-1.39). CONCLUSIONS: Females and patients over 50 seem to be more vulnerable to renal impairment. Potentially modifiable risk factors and exposure to tenofovir disoproxil-fumarate or ritonavir-boosted protease-inhibitors are present even in earlier stages of chronic kidney dysfunction. It remains to be determined whether early interventions including antiretroviral therapy changes (tenofovir alafenamide, cobicistat) or improving comorbidities management will improve the course of chronic kidney disease.

HIV antiretroviral drug Efavirenz induces anxiety-like and depression-like behavior in rats: evaluation of neurotransmitter alterations in the striatum.

Efavirenz (EFV) is an effective antiretroviral drug with a favorable pharmacokinetic profile and widely used in combination regimens to treat HIV infection. However, there are major concerns about the safety of this drug. Patients treated with EFV often experience neuropsychiatric adverse effects, which frequently lead to switching to alternative EFV-free regimens. The mechanisms involved in the central action of EFV are intrinsically unclear. Thus, this study aimed to investigate the effects of acute and subchronic (2 weeks) EFV administration in a series of behavioral tests for anxiety-like and depression-like behavior in healthy rats. We also evaluated the effect of EFV treatment in striatal concentrations of monoamine neurotransmitters (serotonin, dopamine and noradrenaline) and their metabolites and the amino acid neurotransmitters glutamate and GABA. Our results showed that acute treatment with EFV induced an anxiogenic-like effect, while sub-chronic treatment induced both anxiogenic-like and depressive-like behavior which was dose related.. Additionally, EFV treatment caused marked alterations in the striatal concentrations of monoamines and their metabolites (and turnover rates) and the amino acid neurotransmitters glutamate and GABA. These changes were influenced by treatment duration and dose. These findings add more evidence about the neuropsychiatric adverse effects of EFV and propose potential new mechanisms for the toxic action of this drug in the central nervous system.

The CYP2B6 G516T polymorphism influences CD4+ T-cell counts in HIV-positive patients receiving antiretroviral therapy in an ethnically diverse region of the Amazon.

OBJECTIVES: Cytochrome P450 (CYP) enzyme polymorphisms seem to significantly influence the variability of the responses to certain antiretroviral drugs and their toxicity levels. The objective of this study was to evaluate the influence of the CYP2B6 G516T polymorphism on hepatic, renal, immunological, and viral marker changes in HIV-1-positive patients receiving treatment in an ethnically diverse region of the Amazon. METHODS: CYP2B6 G516T genotyping was performed by real-time PCR (RT-PCR) in samples from 185 patients. Urea, creatinine, aspartate aminotransferase (AST), alanine aminotransferase (ALT), CD4+/CD8+ T-cell counts, and HIV-1 plasma viral load were measured. RESULTS: The polymorphic CYP2B6 G516T allele frequency was 0.36, which is different from the frequencies in other ethnic groups. The polymorphic genotype was associated with changes in the urea and ALT levels, although the median values were within the normal range. The TT genotype was also associated with significantly lower CD4+ T-cell counts in patients using efavirenz. CONCLUSIONS: The CYP2B6 G516T polymorphism seems to affect the response to efavirenz treatment by reducing CD4+ T-cell counts in patients with a high degree of miscegenation who use this antiretroviral agent.

Avaliação dos mecanismos envolvidos na permeabilidade de fármacos antirretrovirais por meio do modelo de perfusão in situ em ratos / Evaluation of mechanisms involved in the permeability of antiretroviral drugs using the intestinal in situ perfusion model in rats

Para medicamentos administrados oralmente, as etapas de liberação do fármaco a partir da forma farmacêutica e sua subsequente absorção constituem importantes processos para que a adequada biodisponibilidade oral ocorra. Deste modo, as características de solubilidade e de permeabilidade são de extrema importância para que mecanismos relacionados à absorção sejam compreendidos no âmbito das propriedades ADME (absorção, distribuição, metabolismo e excreção). Com base nisso, o Sistema de Classificação Biofarmacêutica (SCB) foi proposto como uma ferramenta que permite a classificação de fármacos em quatro classes distintas de acordo com a solubilidade e permeabilidade. De maneira complementar, o Sistema de Classificação Biofarmacêutica de Distribuição de Fármacos (SCBDF) foi proposto levando em consideração a solubilidade e o metabolismo das substâncias, além de considerar o impacto de transportadores presentes nos tecidos biológicas, inclusive no trato gastrintestinal (TGI). Assim, o presente trabalho teve como objetivo avaliar os mecanismos envolvidos na permeabilidade de fármacos antirretrovirais (estavudina, lamivudina e zidovudina) por meio do modelo de perfusão in situ com coleta de sangue mesentérico em ratos, considerando os aspectos relacionados ao efluxo e ao metabolismo pré-sistêmico que ocorrem nos enterócitos. Além disso, estudos in vitro em culturas celulares MDCK e MDCK-MDR1 foram realizados a fim de auxiliar na elucidação dos mecanismos de transporte dos referidos fármacos. Para a realização dos estudos de perfusão in situ, ratos Wistar foram anestesiados e a porção do jejuno foi canulada para permitir a entrada do fármaco solubilizado no interior do intestino, bem como a coleta das amostras de perfusato em intervalos regulares de tempo. A veia mesentérica também foi canulada para viabilizar a obtenção das amostras de sangue durante os experimentos. Para os estudos de efluxo, o verapamil foi adicionado à solução de perfusão como inibidor de Pgp (glicoproteína-P), enquanto que o cetoconazol foi empregado como inibidor de enzimas CYP3A. Em modelo in vitro MDCK e MDCK-MDR1, os experimentos foram conduzidos bidirecionalmente com o uso de GG918 como inibidor de P-gp. Em todos os experimentos realizados, o metoprolol e a ranitidina foram empregados como marcadores de alta e de baixa permeabilidade, respectivamente. Os resultados de permeabilidade mostraram que a estavudina e a zidovudina apresentam características de alta permeabilidade, enquanto a lamivudina apresentou o menor resultado dentre os três fármacos. Os ensaios bidirecionais em MDCK, no entanto, mostraram que os três antirretrovirais apresentam baixos valores de permeabilidade, uma vez que seus resultados foram significativamente menores que o valor encontrado para o metoprolol. Com relação à avaliação do mecanismo de efluxo, tanto a lamivudina quanto a zidovudina apresentaram interações significativas com a P-gp nos dois métodos empregados (perfusão in situ e MDCK-MDR1), uma vez que o aumento nos valores de permeabilidade foi constatado quando o inibidor de P-gp foi empregado. Os estudos de metabolismo intestinal realizados por meio do modelo de perfusão in situ mostraram que nenhum dos fármacos antirretrovirais apresentou interação significativa com as enzimas CYP3A quando o cetoconazol foi empregado como inibidor, uma vez que não foram constatadas mudanças significativas nos valores de permeabilidade. A comparação entre os resultados de permeabilidade efetiva (Pef) e de permeabilidade aparente (Pap), obtidos por meio da quantificação das amostras de perfusato e de plasma, respectivamente, permitiu verificar que as diferenças estatísticas entre estes dois parâmetros podem indicar variados mecanismos de transporte, uma vez que a Pap constata a quantidade da substância que realmente foi capaz de superar as barreiras físicas e bioquímicas presentes na parede do TGI. Logo, a Pap é considerada um parâmetro mais próximo das condições in vivo. Esta diferença foi constatada apenas para a zidovudina nos ensaios de transporte de efluxo, uma vez que o valor médio de Pef não representou a mesma conclusão fornecida pelo valor médio de Pap. Os resultados obtidos permitiram concluir que os fármacos antirretrovirais apresentam permeabilidade de moderada a alta em função do possível envolvimento de carreadores de influxo. Além disso, os três fármacos antirretrovirais interagiram de alguma forma com a P-gp, sendo os resultados referentes à lamivudina e à zidovudina mais significativos. Embora tenha sido constatada o envolvimento da P-gp na permeabilidade da zidovudina, sua elevada fração absorvida indica que a absorção desta substância não é limitada por este mecanismo e que a ação do carreador de efluxo não é clinicamente relevante neste caso. Com relação aos estudos de metabolismo, a presença de enzimas CYP3A nos enterócitos também não representou uma condição desfavorável para a absorção dos antirretrovirais. Assim, a avaliação dos mecanismos no presente trabalho contribuiu para a caracterização biofarmacêutica da estavudina, lamivudina e zidovudina e as metodologias descritas podem ser empregadas nas etapas iniciais de desenvolvimento farmacêutico com o objetivo de assegurar a segurança e a eficácia de medicamentos.

For orally administered pharmaceutical products, the drug release from the dosage form and its absorption are considered important processes for adequate oral bioavailability. Thus, the solubility and permeability characteristics are extremely important for understanding of mechanisms related to the absorption in the scope of the ADME properties (absorption, distribution, metabolism and excretion). Based on that, the Biopharmaceutics Classification System (BCS) was proposed as a tool for classifying drugs into four classes considering their solubility and permeability characteristics. In an additional way, the Biopharmaceutics Drug Disposition Classification System (BDDCS) was proposed considering the solubility and metabolism of compounds. Besides, the BDDCS also considers the impact of transporters in biological tissues, such as in the gastrointestinal tract (GIT). Thus, this study aimed to evaluate the mechanisms involved in the permeability of antiretroviral drugs (stavudine, lamivudine and zidovudine) using the intestinal in situ perfusion model with mesenteric blood sampling in rats, considering efflux and intestinal pre-systemic metabolism that occur in the enterocytes. Furthermore, in vitro studies in cell cultures MDCK and MDCK-MDR1 were performed in order to elucidate the transport mechanisms of the drugs. For intestinal in situ perfusion studies, Wistar rats were anesthetized and a portion of jejunum was cannulated to allow the drug entry into the intestine, as well as the perfusate sampling at regular time intervals. The mesenteric vein was also cannulated to allow blood sampling during the experiments. For efflux studies, verapamil was used as P-gp (P-glycoprotein) inhibitor while ketoconazole was used as CYP3A inhibitor. In in vitro model MDCK and MDCK-MDR1, the experiments were performed bidirectionally using GG918 as P-gp inhibitor. For all experiments, metoprolol and ranitidine were used as markers of high and low permeability, respectively. Permeability results showed that stavudine and zidovudine present high permeability characteristics while lamivudine showed the lowest value. However, bidirectional studies in MDCK showed that the antiretroviral drugs present low permeability since their results are far from metoprolol's results. Regarding efflux studies, both lamivudine and zidovudine presented relevant interaction with P-gp in in situ perfusion and MDCK-MDR1 models, since the increase in permeability values was observed when P-gp inhibitor was added. Metabolism studies performed through intestinal in situ perfusion showed that none of antiretroviral drugs interact significantly with CYP3A enzymes, since that no variation in permeability results were noticed. Comparison between effective permeability (Peff) and apparent permeability (Papp), obtained from prefusate and plasma, respectively, allowed to check that statistical differences between these two parameters can indicate different transport mechanisms, since Papp is related to the drug amount that really overcome the physical and biochemical barriers in the gut. Thus, Papp is considered the closest parameter to in vivo condition. This difference was observed for zidovudine in efflux studies, since Peff values does not match with the conclusion provided by the Papp. The results obtained allowed to conclude that the antiretroviral drugs presents moderate to high permeability due to the involvement of influx carriers. Furthermore, the antiretroviral drugs interacted with the P-gp, but lamivudine and zidovudine showed significant results. Although the involvement between zidovudine and P-gp is observed, its high fraction absorbed indicates that the absorption is not limited by efflux transporter, which is not relevant clinically. Regarding 32 metabolism studies, CYP3A enzymes is not considered as a limiting condition for absorption of the antiretroviral drugs. Thus, the evaluation of the mechanisms contributes for biopharmaceutical characterization of stavudine, lamivudine and zidovudine and the methodologies used in this study can be applied in early drug development to ensure adequate safety and efficacy of pharmaceutical products.

Avaliação dos mecanismos envolvidos na permeabilidade de fármacos antirretrovirais por meio dos modelos ex vivo ( células de Franz ) e in vitro ( PAMPA ) / Evaluation of mechanisms involved in the permeability of antiretroviral drugs through ex vivo ( Franz cells ) and in vitro ( PAMPA ) models

Para fármacos administrados por via oral, o controle da extensão e da velocidade de absorção depende basicamente de duas importantes etapas: solubilidade do fármaco nos líquidos fisiológicos e sua permeabilidade através das membranas biológicas. Assim, o Sistema de Classificação Biofarmacêutica (SCB) foi proposto como uma ferramenta para o desenvolvimento de novos fármacos, de novas formulações e para auxiliar nos processos de bioisenção. No entanto, outro fator relacionado à biodisponibilidade e que deve ser considerado nos estudos biofarmacêuticos é o metabolismo. Desta forma, o Sistema de Classificação Biofarmacêutica de Distribuição de Fármacos (SCBDF) foi proposto com a finalidade de classificar os fármacos de acordo com suas características de solubilidade e de metabolismo de modo que seja possível avaliar e predizer o comportamento do fármaco in vivo. O metabolismo tem sido amplamente investigado, sobretudo as enzimas do citocromo P450, as quais estão presentes também nos enterócitos. Além disso, o SCBDF oferece um suporte quanto à avaliação dos mecanismos de permeabilidade envolvidos nos processos de absorção, interações fármaco-fármaco e interações fármaco-alimento. Assim, o presente trabalho teve como objetivo elucidar os mecanismos envolvidos na permeabilidade de fármacos antirretrovirais por meio dos modelos ex vivo (câmaras de difusão vertical tipo Franz) e in vitro (PAMPA, MDCK-MDR1 e microssomas) considerando os aspectos relacionados ao metabolismo intestinal e ao efluxo destes fármacos. Dada a importância da utilização de fármacos antirretrovirais na terapia medicamentosa contra a Síndrome da Imunodeficiência Adquirida (SIDA) e que estes medicamentos são normalmente administrados cronicamente, a compreensão dos mecanismos envolvidos na permeabilidade é de suma importância, uma vez que estes não estão totalmente esclarecidos e poucas informações são encontradas na literatura. Além disso, a biodisponibilidade de fármacos como estavudina, lamivudina e zidovudina indica variação na permeabilidade, necessitando de uma investigação científica mais aprofundada dos processos absortivos. Assim, segmentos de jejuno provenientes de ratos machos Wistar foram utilizados para a avaliação da permeabilidade intestinal dos referidos antirretrovirais considerando a avaliação de efluxo pela glicoproteína-P e o metabolismo intestinal pela CYP3A. De maneira complementar, estudos in vitro com o emprego de membranas artificiais paralelas (PAMPA) e culturas celulares de MDCK-MDR1 foram realizados com a finalidade de auxiliar na elucidação dos mecanismos de permeabilidade dos fármacos antirretrovirais. Além disso, a avaliação do metabolismo dos referidos fármacos foi realizada com o emprego de microssomas a fim de verificar se tais substâncias são substratos de enzimas da família CYP3A e, assim, verificar o impacto do metabolismo intestinal na absorção. Os resultados de permeabilidade obtidos em PAMPA foram: 0,74±0,11 x 10-6 cm/s para a estavudina, 0,25±0,12 x 10-6 cm/s para a lamivudina e 1,14±0,25 x 10-6 cm/s para a zidovudina. Já no modelo ex vivo com o emprego de câmaras de difusão vertical tipo Franz, os resultados foram: 1,56±0,32 x 10-5 cm/s para a estavudina, 1,26±0,27 x 10-5 cm/s para a lamivudina e 2,54±0,49 x 10-5 cm/s para a zidovudina. Portanto, com base nos resultados obtidos a partir dos dois métodos empregados, sugere-se que 30 outro mecanismo de transporte que não envolva a permeabilidade por difusão transcelular passiva possa estar relacionado à permeabilidade dos fármacos antirretrovirais. Com relação aos estudos de efluxo, os resultados obtidos a partir dos experimentos realizados em câmaras de difusão vertical tipo Franz demonstraram o aumento significativo da permeabilidade dos três antirretrovirais quando o inibidor de P-gp foi empregado, sendo: de 15,6 x 10-6 para 42,5 x 10-6 cm/s para a estavudina, de 12,6 x 10-6 para 37,5 x 10-6 cm/s para a lamivudina e de 25,4 x 10-6 para 56,6 x 10-6 cm/s para a zidovudina. Em culturas celulares MDCK-MDR1, os resultados de permeabilidade foram utilizados para a obtenção das razões entre as direções B→A e A→B. Os valores de Papp na condição inibida para os fármacos estudados apresentaram razão menor do que 1. Já a razão B→A/A→B para cada fármaco nos ensaios sem inibidor apresentou-se igual ou maior que 2, evidenciando a interação fármaco-transportador. Com base nisso, o modelo ex vivo com o emprego de segmentos intestinais em câmaras de difusão vertical tipo Franz apresentou-se adequado na avaliação do mecanismo de efluxo dos fármacos antirretrovirais, o que foi confirmado com os estudos realizados em MDCK-MDR1. Assim, os fármacos antirretrovirais estudados apresentaram interação significativa com a P-gp. Em relação aos estudos de metabolismo realizados em câmaras de difusão vertical tipo Franz, os resultados demonstraram grande variação na permeabilidade dos três antirretrovirais quando o inibidor de CYP3A foi empregado, sendo: de 15,6 x 10-6 para 23,5 x 10-6 cm/s para a estavudina, de 12,6 x 10-6 para 27,3 x 10-6 cm/s para a lamivudina e de 25,4 x 10-6 para 40,5 x 10-6 cm/s para a zidovudina. Já no modelo que emprega microssomas, os resultados de metabolização na ausência e na presença de inibidor de CYP3A foram: de 16,56% para 19,79% para a estavudina, de 14,56% para 15,55% para a lamivudina e de 17,85% para 16,48% para a zidovudina. Com base nisso, sugerese o emprego de microssomas para a determinação de metabolismo, uma vez que o método ex vivo empregado demonstrou grande variação entre os valores obtidos. Desta forma, observou-se que, para cada fármaco, não houve influência significativa no metabolismo pré-sistêmico relacionado às enzimas do complexo CYP3A, o que indica que a absorção oral das referidas substâncias não é limitada por tais enzimas. Portanto, a utilização dos diferentes métodos empregados no desenvolvimento do presente trabalho permitiu compreender os mecanismos envolvidos no transporte dos fármacos antirretrovirais, o que se torna de grande relevância nas etapas de desenvolvimento farmacêutico de novas moléculas e na compreensão de eventos clínicos ainda não esclarecidos atualmente

For orally administered drugs, control of the extent and rate of absorption depends on two important steps: solubility of the drug in physiological liquids and their permeability across biological membranes. Thus, the Biopharmaceutics Classification System (BCS) has been proposed as a tool for the development of new drugs, new formulations and aid in the biowaiver processes. However, another factor related to bioavailability that should be considered in biopharmaceutic studies is the metabolism. Thus, the Biopharmaceutics Drug Disposition Classification System (BDDCS) has been proposed for drug classification according to their solubility and metabolism characteristics, so it is possible to evaluate and predict the in vivo behavior of a compound. Metabolism has been extensively investigated, especially cytochrome P450 enzymes, which are also expressed in enterocytes. Besides, BDDCS provides support in evaluating the permeability mechanisms involved in the absorption processes, drug-drug interactions and drug-food interactions. Thus, the present study aimed to evaluate the mechanisms of permeability of antiretroviral drugs through the ex vivo (Franz cells) and in vitro (PAMPA, MDCK-MDR1 and microsomes) models considering aspects related to the intestinal metabolism and efflux of these drugs. Given the importance of the use of antiretroviral drugs in drug therapy against Acquired Immune Deficiency Syndrome (AIDS) and that these drugs are usually administered in a long-term way, understanding the mechanisms involved in the permeability is of a great importance, since they are not totally elucidated and no information is found in the literature. In addition, drugs as stavudine, lamivudine and zidovudine indicate variation in the permeability, which require further scientific investigation of absorptive processes. Thus, jejunum segments from rats were used to evaluate the intestinal permeability of these antiretroviral drugs, considering the evaluation of efflux by P-glycoprotein and intestinal metabolism by CYP3A. In a complementary manner, in vitro studies using parallel artificial membranes (PAMPA) and cell cultures MDCK-MDR1 were performed to aid in the elucidation of the permeability mechanisms of antiretroviral drugs. Also, the evaluation of the metabolism was carried out using microsomes to verify if such substances are substrates of CYP3A, and verify the impact of the intestinal metabolism in the absorption. The permeability results obtained in PAMPA were: 0.74±0.11x10-6 cm/s for stavudine, 0.25±0.12x10-6 cm/s for lamivudine and 1.14±0.25x10-6 cm/s for zidovudine. In ex vivo method using the intestinal segments in Franz cells, the results were: 1.56±0.32x10-5 cm/s for stavudine, 1.26±0.27x10-5 cm/s for lamivudine and 2.54±0.49x10-5 cm/s for zidovudine. Thus, based on the results obtained from these two methods, it is suggested that the antiretroviral drugs present other transport mechanism that is different from transcellular passive diffusion. For efflux studies, results obtained from experiments performed in Franz cells shown the increase of the permeability of the three antiretroviral drugs when the P-gp inhibitor was used: from 15.6x10-6 to 42,5x10-6 cm/s for stavudine, from 12.6x10-6 cm/s to 37.5x10-6 cm/s for lamivudine, and 25.4x10-6 to 56.6x10-6 cm/s for zidovudine. In MDCK-MDR1, the permeability results were used for obtaining ratio values between the directions B→A and A→B. The Papp values obtained with 33 inhibitor shown a ratio less than 1. For ratio B→A/A→B for each drug in experiments without inhibitor, the values obtained was equal or greater than 2, which shows the interaction between drug and transporter. Based on that, the ex vivo model using intestinal segments in Franz cells seems to be adequate for evaluation of efflux mechanism of antiretroviral drugs, which was confirmed by MDCK-MDR1 studies. Thus, the antiretroviral drugs presented interaction with P-gp. For metabolism studies in intestinal segments in Franz cells, a wide range of standard deviation was observed for the three antiretroviral drugs when the CYP3A inhibitor was used: from 15.6x10-6 cm/s to 23.5x10-6 cm/s for stavudine, from 12.6x10-6 cm/s to 27.3x10-6 cm/s for lamivudine, and from 25.4x10-6 cm/s to 40.5x10-6 cm/s for zidovudine. In experiments in microsomes, the results of metabolization in the absence and presence of CYP3A inhibitor were: from 16.56 to 19.79% for stavudine, from 14.56 to 15.55% for lamivudine and from 17.85 to 16.48% for zidovudine. Based on that, it is suggested the use of microsomes for metabolism evaluation, since the ex vivo method presented high variability between the results obtained. For each drug, no significative influence in pre-systemic metabolism related to CYP3A enzymes was observed, which indicates that the oral absorption of the drugs is not limited by these enzymes. The use of different methods in this work allowed to understand the mechanisms involved in the transport of antiretroviral drugs, which is of a great relevance in drug development and in the understanding of clinical events currently not clarified

Avaliação dos mecanismos envolvidos na permeabilidade de fármacos antirretrovirais por meio dos modelos ex vivo (células de Franz) e in vitro (PAMPA) / Evaluation of mechanisms involved in the permeability of antiretroviral drugs through ex vivo (Franz cells) and in vitro (PAMPA) models

Para fármacos administrados por via oral, o controle da extensão e da velocidade de absorção depende basicamente de duas importantes etapas: solubilidade do fármaco nos líquidos fisiológicos e sua permeabilidade através das membranas biológicas. Assim, o Sistema de Classificação Biofarmacêutica (SCB) foi proposto como uma ferramenta para o desenvolvimento de novos fármacos, de novas formulações e para auxiliar nos processos de bioisenção. No entanto, outro fator relacionado à biodisponibilidade e que deve ser considerado nos estudos biofarmacêuticos é o metabolismo. Desta forma, o Sistema de Classificação Biofarmacêutica de Distribuição de Fármacos (SCBDF) foi proposto com a finalidade de classificar os fármacos de acordo com suas características de solubilidade e de metabolismo de modo que seja possível avaliar e predizer o comportamento do fármaco in vivo. O metabolismo tem sido amplamente investigado, sobretudo as enzimas do citocromo P450, as quais estão presentes também nos enterócitos. Além disso, o SCBDF oferece um suporte quanto à avaliação dos mecanismos de permeabilidade envolvidos nos processos de absorção, interações fármaco-fármaco e interações fármaco-alimento. Assim, o presente trabalho teve como objetivo elucidar os mecanismos envolvidos na permeabilidade de fármacos antirretrovirais por meio dos modelos ex vivo (câmaras de difusão vertical tipo Franz) e in vitro (PAMPA, MDCK-MDR1 e microssomas) considerando os aspectos relacionados ao metabolismo intestinal e ao efluxo destes fármacos. Dada a importância da utilização de fármacos antirretrovirais na terapia medicamentosa contra a Síndrome da Imunodeficiência Adquirida (SIDA) e que estes medicamentos são normalmente administrados cronicamente, a compreensão dos mecanismos envolvidos na permeabilidade é de suma importância, uma vez que estes não estão totalmente esclarecidos e poucas informações são encontradas na literatura. Além disso, a biodisponibilidade de fármacos como estavudina, lamivudina e zidovudina indica variação na permeabilidade, necessitando de uma investigação científica mais aprofundada dos processos absortivos. Assim, segmentos de jejuno provenientes de ratos machos Wistar foram utilizados para a avaliação da permeabilidade intestinal dos referidos antirretrovirais considerando a avaliação de efluxo pela glicoproteína-P e o metabolismo intestinal pela CYP3A. De maneira complementar, estudos in vitro com o emprego de membranas artificiais paralelas (PAMPA) e culturas celulares de MDCK-MDR1 foram realizados com a finalidade de auxiliar na elucidação dos mecanismos de permeabilidade dos fármacos antirretrovirais. Além disso, a avaliação do metabolismo dos referidos fármacos foi realizada com o emprego de microssomas a fim de verificar se tais substâncias são substratos de enzimas da família CYP3A e, assim, verificar o impacto do metabolismo intestinal na absorção. Os resultados de permeabilidade obtidos em PAMPA foram: 0,74±0,11 x 10-6 cm/s para a estavudina, 0,25±0,12 x 10-6 cm/s para a lamivudina e 1,14±0,25 x 10-6 cm/s para a zidovudina. Já no modelo ex vivo com o emprego de câmaras de difusão vertical tipo Franz, os resultados foram: 1,56±0,32 x 10-5 cm/s para a estavudina, 1,26±0,27 x 10-5 cm/s para a lamivudina e 2,54±0,49 x 10-5 cm/s para a zidovudina. Portanto, com base nos resultados obtidos a partir dos dois métodos empregados, sugere-se que 30 outro mecanismo de transporte que não envolva a permeabilidade por difusão transcelular passiva possa estar relacionado à permeabilidade dos fármacos antirretrovirais. Com relação aos estudos de efluxo, os resultados obtidos a partir dos experimentos realizados em câmaras de difusão vertical tipo Franz demonstraram o aumento significativo da permeabilidade dos três antirretrovirais quando o inibidor de P-gp foi empregado, sendo: de 15,6 x 10-6 para 42,5 x 10-6 cm/s para a estavudina, de 12,6 x 10-6 para 37,5 x 10-6 cm/s para a lamivudina e de 25,4 x 10-6 para 56,6 x 10-6 cm/s para a zidovudina. Em culturas celulares MDCK-MDR1, os resultados de permeabilidade foram utilizados para a obtenção das razões entre as direções B→A e A→B. Os valores de Papp na condição inibida para os fármacos estudados apresentaram razão menor do que 1. Já a razão B→A/A→B para cada fármaco nos ensaios sem inibidor apresentou-se igual ou maior que 2, evidenciando a interação fármaco-transportador. Com base nisso, o modelo ex vivo com o emprego de segmentos intestinais em câmaras de difusão vertical tipo Franz apresentou-se adequado na avaliação do mecanismo de efluxo dos fármacos antirretrovirais, o que foi confirmado com os estudos realizados em MDCK-MDR1. Assim, os fármacos antirretrovirais estudados apresentaram interação significativa com a P-gp. Em relação aos estudos de metabolismo realizados em câmaras de difusão vertical tipo Franz, os resultados demonstraram grande variação na permeabilidade dos três antirretrovirais quando o inibidor de CYP3A foi empregado, sendo: de 15,6 x 10-6 para 23,5 x 10-6 cm/s para a estavudina, de 12,6 x 10-6 para 27,3 x 10-6 cm/s para a lamivudina e de 25,4 x 10-6 para 40,5 x 10-6 cm/s para a zidovudina. Já no modelo que emprega microssomas, os resultados de metabolização na ausência e na presença de inibidor de CYP3A foram: de 16,56% para 19,79% para a estavudina, de 14,56% para 15,55% para a lamivudina e de 17,85% para 16,48% para a zidovudina. Com base nisso, sugerese o emprego de microssomas para a determinação de metabolismo, uma vez que o método ex vivo empregado demonstrou grande variação entre os valores obtidos. Desta forma, observou-se que, para cada fármaco, não houve influência significativa no metabolismo pré-sistêmico relacionado às enzimas do complexo CYP3A, o que indica que a absorção oral das referidas substâncias não é limitada por tais enzimas. Portanto, a utilização dos diferentes métodos empregados no desenvolvimento do presente trabalho permitiu compreender os mecanismos envolvidos no transporte dos fármacos antirretrovirais, o que se torna de grande relevância nas etapas de desenvolvimento farmacêutico de novas moléculas e na compreensão de eventos clínicos ainda não esclarecidos atualmente

For orally administered drugs, control of the extent and rate of absorption depends on two important steps: solubility of the drug in physiological liquids and their permeability across biological membranes. Thus, the Biopharmaceutics Classification System (BCS) has been proposed as a tool for the development of new drugs, new formulations and aid in the biowaiver processes. However, another factor related to bioavailability that should be considered in biopharmaceutic studies is the metabolism. Thus, the Biopharmaceutics Drug Disposition Classification System (BDDCS) has been proposed for drug classification according to their solubility and metabolism characteristics, so it is possible to evaluate and predict the in vivo behavior of a compound. Metabolism has been extensively investigated, especially cytochrome P450 enzymes, which are also expressed in enterocytes. Besides, BDDCS provides support in evaluating the permeability mechanisms involved in the absorption processes, drug-drug interactions and drug-food interactions. Thus, the present study aimed to evaluate the mechanisms of permeability of antiretroviral drugs through the ex vivo (Franz cells) and in vitro (PAMPA, MDCK-MDR1 and microsomes) models considering aspects related to the intestinal metabolism and efflux of these drugs. Given the importance of the use of antiretroviral drugs in drug therapy against Acquired Immune Deficiency Syndrome (AIDS) and that these drugs are usually administered in a long-term way, understanding the mechanisms involved in the permeability is of a great importance, since they are not totally elucidated and no information is found in the literature. In addition, drugs as stavudine, lamivudine and zidovudine indicate variation in the permeability, which require further scientific investigation of absorptive processes. Thus, jejunum segments from rats were used to evaluate the intestinal permeability of these antiretroviral drugs, considering the evaluation of efflux by P-glycoprotein and intestinal metabolism by CYP3A. In a complementary manner, in vitro studies using parallel artificial membranes (PAMPA) and cell cultures MDCK-MDR1 were performed to aid in the elucidation of the permeability mechanisms of antiretroviral drugs. Also, the evaluation of the metabolism was carried out using microsomes to verify if such substances are substrates of CYP3A, and verify the impact of the intestinal metabolism in the absorption. The permeability results obtained in PAMPA were: 0.74±0.11x10-6 cm/s for stavudine, 0.25±0.12x10-6 cm/s for lamivudine and 1.14±0.25x10-6 cm/s for zidovudine. In ex vivo method using the intestinal segments in Franz cells, the results were: 1.56±0.32x10-5 cm/s for stavudine, 1.26±0.27x10-5 cm/s for lamivudine and 2.54±0.49x10-5 cm/s for zidovudine. Thus, based on the results obtained from these two methods, it is suggested that the antiretroviral drugs present other transport mechanism that is different from transcellular passive diffusion. For efflux studies, results obtained from experiments performed in Franz cells shown the increase of the permeability of the three antiretroviral drugs when the P-gp inhibitor was used: from 15.6x10-6 to 42,5x10-6 cm/s for stavudine, from 12.6x10-6 cm/s to 37.5x10-6 cm/s for lamivudine, and 25.4x10-6 to 56.6x10-6 cm/s for zidovudine. In MDCK-MDR1, the permeability results were used for obtaining ratio values between the directions B→A and A→B. The Papp values obtained with 33 inhibitor shown a ratio less than 1. For ratio B→A/A→B for each drug in experiments without inhibitor, the values obtained was equal or greater than 2, which shows the interaction between drug and transporter. Based on that, the ex vivo model using intestinal segments in Franz cells seems to be adequate for evaluation of efflux mechanism of antiretroviral drugs, which was confirmed by MDCK-MDR1 studies. Thus, the antiretroviral drugs presented interaction with P-gp. For metabolism studies in intestinal segments in Franz cells, a wide range of standard deviation was observed for the three antiretroviral drugs when the CYP3A inhibitor was used: from 15.6x10-6 cm/s to 23.5x10-6 cm/s for stavudine, from 12.6x10-6 cm/s to 27.3x10-6 cm/s for lamivudine, and from 25.4x10-6 cm/s to 40.5x10-6 cm/s for zidovudine. In experiments in microsomes, the results of metabolization in the absence and presence of CYP3A inhibitor were: from 16.56 to 19.79% for stavudine, from 14.56 to 15.55% for lamivudine and from 17.85 to 16.48% for zidovudine. Based on that, it is suggested the use of microsomes for metabolism evaluation, since the ex vivo method presented high variability between the results obtained. For each drug, no significative influence in pre-systemic metabolism related to CYP3A enzymes was observed, which indicates that the oral absorption of the drugs is not limited by these enzymes. The use of different methods in this work allowed to understand the mechanisms involved in the transport of antiretroviral drugs, which is of a great relevance in drug development and in the understanding of clinical events currently not clarified

Effectiveness and safety of generic version of abacavir/lamivudine and efavirenz in treatment naïve HIV-infected patients: a nonrandomized, open-label, phase IV study in Cali-Colombia, 2011-2012.

BACKGROUND: Generic drug policies are often associated with concerns about the quality and effectiveness of these products. Phase IV clinical trials may be a suitable design to assess the effectiveness and safety of generic drugs. The objective of this study was to describe the effectiveness and the safety of the generic abacavir/lamivudine and efavirenz in treatment-naïve HIV-infected patients. METHODS: A monocentric, nonrandomized, open-label, phase IV study in treatment naïve HIV-infected patients 18 years or older with indication to receive abacavir/lamivudine and efavirenz were recruited from a program that provides comprehensive outpatient consultation and continuing care. The primary end-point was to achieve viral load <40 copies/mL at 12 months after baseline to assess effectiveness. Secondary end-point of the study were 1) to asses increasing in T-CD4 lymphocytes levels as accompaniment to asses effectiveness, and 2) to assess both gastrointestinal, skin, and central nervous system symptoms, and lipid profile, cardiovascular risk, renal, and hepatic function as safety profile. Data were determined at baseline, 3, 6, and 12 months. Close clinical monitoring and pharmaceutical care were used for data collection. Wilcoxon matched-pairs signed-rank test was used to compare proportions or medians. RESULTS: Sixty patients were invited to participate in the study; 42 were enrolled and 33 completed the follow-up. Of the nine patients excluded from the study, only one was withdrawn due to adverse events. At 12 months, 31 of 42 patients (73.8 % in intention-to-treat analysis) achieved a viral load of HIV1 RNA <40 copies/mL. There was a significant increase (172 cells/mm3) in the median for CD4 T lymphocyte count. The adverse events were mild and met the safety profile for this antiretroviral regimen, mainly of central nervous system symptoms, skin rash, lipid abnormalities, and an increase of 2 % in the median of the percentage of cardiovascular risk. CONCLUSIONS: The clinical outcomes of generic version of abacavir/lamivudine and efavirenz in HIV treatment naïve patients showed the expected safety and effectiveness profile of proprietary ARV drugs. TRIAL REGISTRATION: Registro Público Cubano de Ensayos Clínicos (RPCEC) ID: RPCEC00000202 . Registered 19 November 2015.

[Allergic hypersensitivity to antiretroviral drugs: etravirine, raltegravir and darunavir]. / Hipersensibilidad alérgica a antirretrovirales: etravirina, raltegravir y darunavir.

All antiretroviral drugs can have both short-term and long-term adverse events. The risk of specific side effects varies from drug to drug, from drug class to drug class, and from patient to patient. A better understanding of the adverse effects of antiretroviral agents is of interest not only for HIV specialists, but also for other physicians who care allergy reactions in HIV-positive patients. Each antiretroviral medication is associated with its own specific adverse effects or may cause problems only in particular circumstances. In this article some adverse allergic effects of HAART therapy in the treatment of HIV from a patient are reviewed. Our aim is to gain a working knowledge of these adverse effects, promoting the early recognition and reversal of potentially serious adverse effects, and reducing the potential for adverse drug interactions.

Todos los fármacos antirretrovirales tienen efectos adversos que pueden manifestarse a corto o largo plazo. El riesgo de efectos secundarios específicos varía de un fármaco a otro, de una clase de medicamento a otra y de un paciente a otro. Una mejor comprensión de estos efectos es de interés no sólo para los especialistas en VIH, sino también para otros médicos que atendemos las reacciones alérgicas en los pacientes VIH-positivos. Cada fármaco antirretroviral se asocia con sus propios efectos adversos específicos o puede causar problemas sólo en circunstancias particulares. En este artículo se revisan algunos efectos alérgicos adversos del tratamiento antirretroviral de gran actividad (TARGA) en el tratamiento del VIH de un paciente. Nuestro objetivo es obtener un conocimiento práctico de estos efectos adversos, promoviendo el reconocimiento temprano y la reversión de los efectos adversos graves y reducir las interacciones farmacológicas adversas.

Parenteral antiretroviral formulations are still urgently needed: a case report and commentary.

This case report highlights a challenging clinical dilemma to administer antiretroviral therapy in a critically-ill human immunodeficiency virus-infected patient who presented with multiple opportunistic infections and a non-functional gastrointestinal tract. The need for parenteral antiretroviral drug options is discussed and investigational drugs are briefly reviewed.

Reacciones adversas más frecuentes de los fármacos antirretrovirales

Introducción: las reacciones adversas a los antirretrovirales constituyen un obstáculo para el cumplimiento y la buena adherencia, debido a la gravedad que pueden alcanzar estos efectos, al abandono del tratamiento y/o remplazo del fármaco en cuestión. Objetivos: describir las reacciones a antirretrovirales más frecuentemente observadas. Pacientes y métodos: diseño observacional retrospectivo realizado en varones y mujeres, mayores de edad, portadores de HIV, que consultaron en el Servicio de Atención Integral del Hospital Nacional entre noviembre de 2007 y diciembre 2012. Resultados: fueron incluidos 190 pacientes, en 59 casos (31%) se presentaron efectos secundarios al TARGA. La edad media fue 35 años (rango 19-63 años). El 62,2% de los sujetos correspondían al sexo masculino. Predominaron las manifestaciones neuropsicológicas (28%), dermatológicas (22%) y hematológicas (21%).

Introduction: Adverse reactions to antiretroviral drugs are obstacles for the compliance and good adherence because of their severity, the treatment dropouts and/or the replacement of the drug. Objective: To describe the most frequently observed adverse reactions to antiretroviral drugs. Patients and methods: Retrospective observational design carried out in adult men and women, HIV carriers, who attended the Comprehensive Care Service between November, 2007 and December, 2012. Results: One hundred ninety patients were included and 59 cases (31%) presented side-effects to HAART. Mean age was 35 years (range: 19-63 years) and 62.2% of the subjects were men. Neuropsychological (28%), dermatologic (22%) and hematologic (21%) manifestations predominated.

Evolución rápida de la resistencia a drogas antirretrovirales en 2 pacientes infectados por VIH-1 / Rapid development of resistance to antiretroviral drugs in two patients infected with HIV-1

Introducción: el empleo de la terapia antirretroviral ha facilitado la recuperación lenta y parcial del sistema inmune, lo que permite reducir las complicaciones oportunistas, incrementar la supervivencia y mejorar la calidad de vida en pacientes infectados por el virus de inmunodeficiencia humana tipo 1. Objetivo: determinar las variantes virales de evolución rápida a la resistencia a drogas antirretrovirales en pacientes positivos a VIH-1. Métodos: se estudiaron 2 pacientes positivos a VIH-1; se nombraron con las letras A y B, respectivamente, y se les determinó la resistencia a drogas antirretrovirales en 2 tiempos diferentes: momento del diagnóstico y 2012. Los resultados se relacionaron con variables clínicas. Resultados: el paciente A, en el momento del diagnóstico, presentó un virus subtipo BG con niveles bajos de resistencia a zidovudina y estavudina y el B, virus subtipo B, con bajos niveles de resistencia a zidovudina. En el año 2012, el paciente A mostró una variante viral FRC18_cpx con altos niveles de resistencia a lamivudina, emtricitabina y nevirapina. El paciente B se mantuvo infectado con un virus subtipo B, pero resistente a los inhibidores de la transcriptasa inversa. Conclusiones: estos resultados muestran la dinámica y rápida evolución de las variantes de VIH-1 en pacientes infectados...

Introduction: the use of antiretroviral therapy has facilitated the slow and partial recovery of the immune system, allowing to reduce opportunistic complications, to increase survival and to improve quality of life in patients infected with human immunodeficiency virus type 1. Objective: to determine rapid evolving viral variants with resistance to antiretroviral drugs in HIV-1 positive patients. Methods: two HIV-1 positive patients were studied. They were appointed by the letters A and B, respectively, and antiretroviral drug resistance were determined at two different times: Moment of diagnosis and 2012. Results were related to clinical variables. Results: at the time of diagnosis Patient A had subtype BG virus with low levels of resistance to zidovudine and stavudine. Patient B had subtype B virus with low levels of resistance to zidovudine. In 2012, the patient A showed FRC18-cpx viral variant with high levels of resistance to lamivudine, emtricitabine, and nevirapine. Patient B remained infected with subtype B virus, but resistant to the reverse transcriptase inhibitors. Conclusions: these results show the dynamic and rapidly evolving variants of HIV-1 infected patients...