RESUMO
We tested the influence of four polymorphisms and gene duplication in CYP2D6 on in vivo enzyme activity in a Chilean mestizo population in order to identify the most relevant genetic profiles that account for observed phenotypes in this ethnic group. CYP2D6*2 (2850C>T), *3 (2549A>del), *4 (1846G>A), *17 (1023C>T) and gene duplication were determined by PCR-RFLP or PCRL in a group of 321 healthy volunteers. Individuals with different variant alleles were phenotyped by determining debrisoquine 4-hydroxylase activity as a metabolic ratio (MR) using a validated HPLC assay. Minor allele frequencies were 0.41, 0.01, 0.12 and 0.00 for CYP2D6*2, *3, *4 and *17 variants, respectively, and the duplication frequency was 0.003. Genotype analysis correlated with phenotypes in 18 of 23 subjects (78.3%). 11 subjects were extensive metabolizers (EM), 8 were intermediate metabolizers (IM), 2 were poor metabolizers (PM) and 2 were ultra-rapid metabolizers (UM) which is fairly coincident with expected phenotypes metabolic ratios ranged from 0.11 to 126.41. The influence of CYP2D6*3 was particularly notable, although only heterozygote carriers were present in our population. Individuals homozygous for *4 were always PM. As expected, the only subject with gene duplication was UM. In conclusion, there was a clear effect of genotype on observed CYP2D6 activity. Classification of EM, PM and UM through genotyping was useful to characterize CYP2D6 phenotype in the Chilean mestizo population.
Assuntos
Citocromo P-450 CYP2D6/genética , Citocromo P-450 CYP2D6/metabolismo , Adolescente , Adulto , Chile , Debrisoquina/metabolismo , Feminino , Duplicação Gênica , Frequência do Gene , Estudos de Associação Genética , Humanos , Índios Sul-Americanos/genética , Cinética , Masculino , Polimorfismo Genético , População Branca/genética , Adulto JovemRESUMO
BACKGROUND: Increased cortisol levels and genetic polymorphisms have been related to both major depressive disorder and antidepressant treatment outcome. The aim of this study is to evaluate the relationship between circadian salivary cortisol levels, cortisol suppression by dexamethasone and genetic polymorphisms in some HPA axis-related genes to the response to placebo and fluoxetine in depressed patients. METHODS: The diagnosis and severity of depression were performed using the Mini International Neuropsychiatric Interview (M.I.N.I.) and Hamilton depression scale (HAM-D17), respectively. Euthyroid patients were treated with placebo (one week) followed by fluoxetine (20 mg) (two months). Severity of depression was re-evaluated after placebo, three weeks and two months of fluoxetine treatments. Placebo response was defined as HAM-D17 score reductions of at least 25% and to < 15. Early response and response were reductions of at least 50% after three weeks and two months, and remission with ≤ 7 after two months. Plasma TSH, free-T4, circadian salivary cortisol levels and cortisol suppression by dexamethasone were evaluated. Seven genetic polymorphisms located in the Corticotrophin-releasing-hormone-receptor-1 (rs242939, rs242941, rs1876828), Corticotrophin-releasing-hormone-receptor-2 (rs2270007), Glucocorticoid-receptor (rs41423247), FK506-binding-protein-5 (rs1360780), and Arginine-vasopressin (rs3729965) genes were determined. Association analyses between response to placebo/fluoxetine and polymorphism were performed by chi-square or Fisher exact test. Cortisol levels were compared by t-test, ANOVA and the general linear model for repeated measures. RESULTS: 208 depressed patients were recruited, 187 of whom were euthyroid. Placebo responders, fluoxetine responders and remitters exhibited significantly lower circadian cortisol levels than those who did not respond (p-values of 0.014, 0.008 and 0.021 respectively). Patients who abandoned treatment before the third week also exhibited a trend to low cortisol levels (p = 0.057). The polymorphisms rs242939 (CRHR1) and rs2270007 (CRHR2) were not in Hardy-Weinberg equilibrium. Only the rs242939 polymorphism (CRHR1) exhibited association with early response (three weeks) to fluoxetine (p-value = 0.043). No other association between outcomes and polymorphisms was observed. CONCLUSIONS: These results support the clinical relevance of low salivary cortisol levels as a predictor of antidepressant response, either to placebo or to fluoxetine. Only one polymorphism in the CRHR1 gene was associated with the early response. Other factors may be involved in antidepressant response, although further studies are needed to identify them.
Assuntos
Antidepressivos de Segunda Geração/uso terapêutico , Transtorno Depressivo Maior/tratamento farmacológico , Resistência a Medicamentos/genética , Fluoxetina/uso terapêutico , Hidrocortisona/sangue , Receptores de Hormônio Liberador da Corticotropina/genética , Adolescente , Adulto , Arginina Vasopressina/genética , Transtorno Depressivo Maior/sangue , Feminino , Humanos , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Polimorfismo Genético , Estudos Prospectivos , Escalas de Graduação Psiquiátrica , Receptores de Glucocorticoides/genética , Proteínas de Ligação a Tacrolimo/genética , Resultado do Tratamento , Adulto JovemRESUMO
Introduction.Levonorgestrel a synthetic progestagen used for endometriosis, dysmenorrhea and emergency contraception, is quickly and completely absorbed in the digestive tract. levonorgestrel is predominantly metabolised through hepatic routes that utilise the CYP3A system (CYP3A4 and CYP3A5). Objective.This study aimed to evaluate the association between variant alleles of CYP3A4*1B and CYP3A5*3 polymorphisms and the pharmacokinetics of levonorgestrel. Materials and methods. A group of 17 adult female healthy volunteers who signed an informed consent were genotyped for CYP3A4 and CYP3A5 through PCR-RFLP. Volunteers were submitted to pharmacokinetic analysis where, after a 12-hour overnight fast, they received a single oral dose of 0.75 mg of levonorgestrel. Serial blood samples were obtained (0 to 24 hours), and levonorgestrel concentrations were determined by UPLC-MS/MS to determine pharmacokinetic parameters. The procedures employed herein were performed according to the Declaration of Helsinki and Good Clinical Practices standards. Results. Observed genotype frequencies in the studied group for CYP3A4*1B were 11.8% for *1B/*1B, 5.8% for *1/*1B and 82.4% for *1/*1. CYP3A5*3 frequencies were 70.5% for *3/*3, 23.5% for *1/*3 and 6.5% for *1/*1. A high pharmacokinetic variability between volunteers was observed, but no statistical association of pharmacokinetic parameters was found within the studied CYP3A4/5 polymorphisms. Conclusions. Genetic polymorphisms could be important factors in determining inter-patient variability in plasma levonorgestrel concentrations, which in this study were not significantly associated with the presence of CYP3A4*1B and CYP3A5*3 polymorphisms. Therefore, due to the significant inter-patient variability that we observed during the course of this study, it is necessary to carry out studies with larger number of volunteers.
Introducción. El levonorgestrel, un progestágeno sintético usado para endometriosis, dismenorrea y anticoncepción de emergencia, es rápida y completamente absorbido en el tubo digestivo. Su metabolismo es principalmente hepático, mediante las enzimas CYP3A4 y CYP3A5. Objetivo. El presente estudio tuvo como objetivo evaluar la asociación entre la farmacocinética de levonorgestrel y las variantes alélicas de CYP3A4*1B y CYP3A5*3. Materiales y métodos. En un grupo de 17 mujeres adultas sanas, que firmaron un consentimiento informado, se practicó genotipificación para CYP3A4*1B y CYP3A5*3 mediante PCR. Posteriormente, las voluntarias fueron sometidas a un estudio farmacocinético donde, luego de 12 horas de ayuno, recibieron una dosis de 0,75 mg de levonorgestrel. Se extrajeron muestras sanguíneas seriadas (0 a 24 horas) y se determinaron las concentraciones de levonorgestrel mediante un método validado de UPLC-ms/ms, para luego obtener los parámetros farmacocinéticos. Todos los procedimientos consideraron los aspectos éticos de la Declaración de Helsinki y las buenas prácticas clínicas. Resultados. Las frecuencias genotípicas observadas para el grupo de estudio fueron 11,8 % para *1B/*1B; 5,8 % para *1/*1B, y 82,4 % para *1/*1 de CYP3A4*1B. Para CYP3A5*3, las frecuencias genotípicas fueron 70,5 % para *3/*3; 23,5 % para *1/*3, y 6,5 % para *1/*1. Se observa una interesante variabilidad entre las voluntarias que sugiere una relación con las variantes genéticas CYP3A, pero que no permite establecer una asociación estadísticamente significativa, presumiblemente debido al bajo número de individuos homocigotos mutados de CYP3A4 y silvestres de CYP3A5. Conclusiones. Los polimorfismos genéticos podrían ser factores relevantes en la determinación de la variabilidad entre pacientes en las concentraciones plasmáticas de levonorgestrel, lo cual, sin embargo, no pudo ser establecido estadísticamente en este estudio. Por lo tanto, resulta necesario continuar este tipo de estudios con mayor número de voluntarios para establecer una asociación entre la variabilidad observada y la presencia de estos polimorfismos.
Assuntos
Adulto , Feminino , Humanos , Adulto Jovem , /genética , Levanogestrel/farmacocinética , Polimorfismo Genético , Alelos , Biotransformação/genética , Chile , /metabolismo , Frequência do Gene , Genótipo , Levanogestrel/sangue , Projetos Piloto , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas/genética , Isoformas de Proteínas/genéticaRESUMO
INTRODUCTION: Levonorgestrel a synthetic progestagen used for endometriosis, dysmenorrhea and emergency contraception, is quickly and completely absorbed in the digestive tract. levonorgestrel is predominantly metabolised through hepatic routes that utilise the CYP3A system (CYP3A4 and CYP3A5). OBJECTIVE: This study aimed to evaluate the association between variant alleles of CYP3A4*1B and CYP3A5*3 polymorphisms and the pharmacokinetics of levonorgestrel. MATERIALS AND METHODS: A group of 17 adult female healthy volunteers who signed an informed consent were genotyped for CYP3A4 and CYP3A5 through PCR-RFLP. Volunteers were submitted to pharmacokinetic analysis where, after a 12-hour overnight fast, they received a single oral dose of 0.75 mg of levonorgestrel. Serial blood samples were obtained (0 to 24 hours), and levonorgestrel concentrations were determined by UPLC-MS/MS to determine pharmacokinetic parameters. The procedures employed herein were performed according to the Declaration of Helsinki and Good Clinical Practices standards. RESULTS: Observed genotype frequencies in the studied group for CYP3A4*1B were 11.8% for *1B/*1B, 5.8% for *1/*1B and 82.4% for *1/*1. CYP3A5*3 frequencies were 70.5% for *3/*3, 23.5% for *1/*3 and 6.5% for *1/*1. A high pharmacokinetic variability between volunteers was observed, but no statistical association of pharmacokinetic parameters was found within the studied CYP3A4/5 polymorphisms. CONCLUSIONS: Genetic polymorphisms could be important factors in determining inter-patient variability in plasma levonorgestrel concentrations, which in this study were not significantly associated with the presence of CYP3A4*1B and CYP3A5*3 polymorphisms. Therefore, due to the significant inter-patient variability that we observed during the course of this study, it is necessary to carry out studies with larger number of volunteers.
Assuntos
Citocromo P-450 CYP3A/genética , Levanogestrel/farmacocinética , Polimorfismo Genético , Adulto , Alelos , Biotransformação/genética , Chile , Citocromo P-450 CYP3A/metabolismo , Feminino , Frequência do Gene , Genótipo , Humanos , Levanogestrel/sangue , Projetos Piloto , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas/genética , Isoformas de Proteínas/genética , Adulto JovemRESUMO
Antecedentes: La mayoría de los pacientes que reciben tratamientos con anticoagulantes orales por periodos prolongados presentan variabilidad en la respuesta. El acenocumarol es el anticoagulante oral más prescrito en nuestro país, es biotransformado principalmente por CYP2C9 e investigaciones recientes demuestran que la variante CYP2C9*2 es una de las responsables de la variabilidad de respuesta a acenocumarol. Objetivo: Determinar las diferencias en los parámetros farmacocinéticos de acenocumarol en voluntarios que presentan la variante alélica CYP2C9*2. Métodos: Se estudiaron 24 voluntarios sanos. La detección de genotipos se realizó mediante PCR-RFLP y los parámetros farmacocinéticos se obtuvieron mediante la concentración plasmática de acenocumarol usando un método validado para UPLC-MS/MS. Resultados: Del total de 24 voluntarios, 19 tenían el genotipo CYP2C9*1/*1 (wt/wt), 4 tenían genotipo CYP2C9*1/*2 (heterocigoto) y 1 voluntario tenía genotipo de CYP2C9*2/*2 (homocigoto recesivo). Los parámetros farmacocinéticos del acenocumarol no fueron significativamente diferentes entre los individuos con genotipo CYP2C9*2 y CYP2C9*1. Sin embargo, la farmacocinética de acenocumarol del individuo CYP2C9*2/*2 mostró diferencias relevantes con respecto a la observada en el grupo CYP2C9*1/*1 (tmáx aumentó 1,4 veces, ke disminuyó 1,8 veces y t1/2 aumentó 1,7 veces). Conclusión: La farmacocinética de acenocumarol en el individuo con el genotipo CYP2C9*2/*2 refleja una potencial relevancia de este polimorfismo en el tratamiento con acenocumarol.
Background: Most of the patients receiving anticoagulant therapy for extended periods show variability in their clinical response. Acenocumarol, the most commonly prescribed oral anticoagulant in our country, is biotransformed mainly through CYP2C9 and recent research shows that CYP2C9*2 variant is partly responsible for the variable response to ace-nocumarol. Aim: to determine pharmacokinetics parameters of acenocumarol in volunteers exhibiting the CYP2C9*2 polymorphic variant. Methods: Genotype detection was performed using PCR-RFLP and pharmacokinetics parameters were obtained from the acenocumarol concentrations, using a UPLC-MS/MS validated method. The project was approved by the institutional Ethics Committee of the University of Chile's Faculty of Medicine. Results: 19 out of 24 volunteers had the CYP2C9*1/*1 genotype, 4 the CYP2C9*1/*2 genotype (heterozygous) and 1 subject had the CYP2C9*2/*2 genotype (recessive homozygous). No statistically significant differences between acenocumarol pharmacokinetics parameters of CYP2C9*2 compared to those with normal variant, CYP2C9*1were observed.. However, a single individual with the CYP2C9*2/*2 genotype showed different phar-macokinetics parameters: tmáx and t1/2 were increased 1.4 and 1.7 times, respectively, and kc was 1.8 times lower compared to the group with the CYP2C9*1/*1 genotype. Conclusion: There are clear differences in genotype-dependent acenocoumarol pharmacokinetics in individuals with the CYP2C9*2/*2 genotype, reflecting a potential relevance of this polymorphism in anticoagulation with acenocumarol.
Assuntos
Humanos , Masculino , Feminino , Adulto , Acenocumarol/farmacocinética , Anticoagulantes/farmacocinética , Hidrocarboneto de Aril Hidroxilases/genética , Genótipo , Hidrocarboneto de Aril Hidroxilases/metabolismo , Farmacogenética , Reação em Cadeia da Polimerase em Tempo RealRESUMO
OBJECTIVE: The aim of this study was to compare the pharmacokinetic parameters between two brands of pregabalin in healthy Chilean volunteers. METHODS: A randomized, single-dose, two-period, two-sequence, crossover study design with a 2-week washout period was conducted in healthy Chilean males. Plasma samples were collected over a 12-hour period after administration of 150 mg pregabalin in each period. A validated ultra-performance liquid chromatography with positive ionization mass spectrometric detection method was used to analyze pregabalin concentration in plasma. Pharmacokinetic parameters were determined using a noncompartmental method. Bioequivalence between the test and reference products was determined when the ratio for the 90% confidence intervals (CIs) of the difference in the means of the log-transformed area under the curve (AUC)(0-t), AUC(0-∞), and maximum concentration (C(max)) of the two products were within 0.80 and 1.25. RESULTS: The study was carried out on 22 healthy Chilean volunteers. The mean (SD) C(max), AUC(0-t) and AUC(0-∞) of the test formulation (Pregobin™) of pregabalin were 2.10 (0.56) µg/ml, 10.35 (2.00) µgxh/ml and 13.92 (2.74) µgxh/ml, respectively. The mean (SD) C(max), AUC(0-t) and AUC(0-∞) of the reference formulation (Lyrica™) of pregabalin were 2.15 (0.52) µg/ml, 10.31 (1.85) µgxh/ml and 13.78 (2.25) µgxh/ml, respectively. The parametric 90% CIs for C(max), AUC(0-t), and AUC(0-∞) were 0.97-1.13, 1.01-1.04, and 0.98-1.02, respectively. CONCLUSIONS: These results suggest that both products are bioequivalent and can be used as interchangeable options in the clinical setting.
