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1.
Clin Pharmacol Ther ; 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33448339

RESUMO

The Pharmacogene Variation Consortium (PharmVar) catalogues star (*) allele nomenclature for the polymorphic human CYP2B6 gene. Genetic variation within the CYP2B6 gene locus impacts the metabolism or bioactivation of clinically important drugs. Of particular importance are efficacy and safety concerns regarding: efavirenz, which is used for the treatment of HIV type-1 infection; methadone, a mainstay in the treatment of opioid use disorder and as an analgesic; ketamine, used as an antidepressant and analgesic; and bupropion, which is prescribed to treat depression and for smoking cessation. This GeneFocus provides a comprehensive overview and summary of CYP2B6 and describes how haplotype information catalogued by PharmVar is utilized by the Pharmacogenomics Knowledgebase (PharmGKB) and the Clinical Pharmacogenetics Implementation Consortium (CPIC).

2.
Pharmacotherapy ; 2020 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-33345336

RESUMO

STUDY OBJECTIVE: Methadone is associated with QT interval prolongation and torsades de pointes. The objective of this study was to (a) determine the incidence of QT interval prolongation among patients on maintenance methadone therapy in an urban opioid treatment program (OTP), (b) compare characteristics of patients who developed methadone-associated QT prolongation with those who did not develop QT prolongation, and (c) investigate the relationship between QT interval prolongation and stereospecific serum methadone and metabolite [2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP)] concentrations. DESIGN: Prospective study. SETTING: Urban opioid treatment program (OTP). PATIENTS: n = 93 patients on maintenance methadone therapy in an urban OTP. INTERVENTION: Patients underwent a 12-lead electrocardiogram (ECG) prior to initiating methadone and again during steady-state maintenance methadone therapy. In a subset (n = 43), blood was obtained to determine serum (S)- and (R)-methadone and (S)- and (R)-EDDP concentrations, which were compared in patients who developed Bazett's-corrected QT (QTc) prolongation [≥470 ms (men) or ≥480 ms (women) and/or ≥60 ms lengthening from pretreatment value] with those who did not have QTc prolongation. MEASUREMENTS AND MAIN RESULTS: Mean [± standard deviation (SD)] age was 36 ± 12 years; 73% were female, and 74% were white. QTc prolongation occurred in 14 (15.1%) patients. Patients who developed QTc prolongation were older (41 ± 13 vs. 35 ± 9 years, p = 0.03) and had a longer pre-methadone QTc compared with those who did not have QTc prolongation (429 ± 11 vs. 420 ± 20 ms, respectively, p = 0.02). Serum (S)-methadone concentrations were higher in patients with QTc prolongation compared to patients without prolongation (199 ± 81 vs. 128 ± 68 ng/ml, respectively, p = 0.01), whereas the difference in serum (R)-methadone concentrations between the groups did not reach significance (189 ± 68 vs. 125 ± 60 ng/ml, respectively, p = 0.08). Serum (R)-methadone concentrations correlated with QTc intervals [R2  = 0.15 (95% confidence interval (CI) 0.11-0.62, p = 0.0009)]. The correlation between serum (S)-methadone concentrations and QTc did not reach significance [R2  = 0.08 (95% CI -0.01 to 0.54, p = 0.06)]. Serum (S)-and (R)-EDDP concentrations were not significantly different between the groups and did not significantly correlate with QTc intervals. CONCLUSIONS: Approximately 15% of patients taking maintenance methadone therapy developed QT interval prolongation. Both serum (S)- and (R)-methadone concentrations, but not (S)- or (R)-EDDP, contribute to methadone-associated QT prolongation.

3.
Clin Pharmacol Ther ; 2020 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-32770672

RESUMO

Proton pump inhibitors (PPIs) are widely used for acid suppression in the treatment and prevention of many conditions, including gastroesophageal reflux disease, gastric and duodenal ulcers, erosive esophagitis, Helicobacter pylori infection, and pathological hypersecretory conditions. Most PPIs are metabolized primarily by cytochrome P450 2C19 (CYP2C19) into inactive metabolites, and CYP2C19 genotype has been linked to PPI exposure, efficacy, and adverse effects. We summarize the evidence from the literature and provide therapeutic recommendations for PPI prescribing based on CYP2C19 genotype (updates at www.cpicpgx.org). The potential benefits of using CYP2C19 genotype data to guide PPI therapy include (i) identifying patients with genotypes predictive of lower plasma exposure and prescribing them a higher dose that will increase the likelihood of efficacy, and (ii) identifying patients on chronic therapy with genotypes predictive of higher plasma exposure and prescribing them a decreased dose to minimize the risk of toxicity that is associated with long-term PPI use, particularly at higher plasma concentrations.

4.
Clin Pharmacol Ther ; 2020 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-32772362

RESUMO

The CYP2B6 gene is highly polymorphic and its activity shows wide interindividual variability. However, substantial variability in CYP2B6 activity remains unexplained by the known CYP2B6 genetic variations. Circulating, cell-free micro RNAs (miRNAs) may serve as biomarkers of hepatic enzyme activity. CYP2B6 activity in 72 healthy volunteers was determined using the disposition of efavirenz as a probe drug. Circulating miRNA expression was quantified from baseline plasma samples. A linear model consisting of the effects of miRNA expression, genotype-determined metabolizer status, and demographic information was developed to predict CYP2B6 activity. Expression of 2,510 miRNAs were quantified out of which 7 miRNAs, together with the CYP2B6-genotypic metabolizer status and demographics, was shown to be predictive markers for CYP2B6 activity. The reproducibility of the model was evaluated by cross-validation. The average Pearson's correlation (R) between the predicted and observed maximum plasma concentration (Cmax ) ratios of efavirenz and its metabolite-8-OH efavirenz using the linear model with all features (7 miRNA + metabolizer status + age + sex + race) was 0.6702. Similar results were also observed using area under the curve (AUC) ratios (Pearson correlation's R = 0.6035). Thus, at least 36% (R2 ) of the variability of in vivo CYP2B6 activity was explained using this model. This is a significant improvement over the models using only the genotype-based metabolizer status or the demographic information, which explained only 6% or less of the variability of in vivo CYP2B6 activity. Our results, therefore, demonstrate that circulating plasma miRNAs can be valuable biomarkers for in vivo CYP2B6 activity.

5.
J Clin Psychiatry ; 81(5)2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32857933

RESUMO

BACKGROUND: Selective serotonin reuptake inhibitors (SSRIs) are commonly used to treat pediatric anxiety disorders, including generalized anxiety disorder (GAD); however, their efficacy and tolerability are difficult to predict. This study evaluated the efficacy and tolerability of escitalopram in adolescents with GAD (DSM-IV-TR) and the impact of variants in HTR2A and serotonin transporter (SLC6A4) genes and cytochrome P450 2C19 (CYP2C19) phenotypes on response as well as CYP2C19 phenotype on escitalopram pharmacokinetics from February 2015 through November 2018. METHODS: Patients were treated with escitalopram (forced titration to 15 mg/d, then flexible titration to 20 mg/d) (n = 26, mean ± SD age: 14.8 ± 1.7 years) or placebo (n = 25, mean ± SD age: 14.9 ± 1.6 years) for 8 weeks. Outcomes were the change in scores on the Pediatric Anxiety Rating Scale (PARS) and Clinical Global Impressions (CGI) scales as well as vital signs and adverse events. Plasma escitalopram and desmethylcitalopram area under the curve during 24 hours (AUC0-24) and maximum concentration (Cmax) were determined and compared across CYP2C19 phenotypes. RESULTS: Escitalopram was superior to placebo for mean ± SD baseline-to-endpoint change in PARS (-8.65 ± 1.3 vs -3.52 ± 1.1, P = .005) and CGI scores, and increasing CYP2C19 metabolism was associated with decreases in escitalopram Cmax (P = .07) and AUC0-24 (P < .05). Vital signs, corrected QT interval, and adverse events were similar in patients who received escitalopram and placebo. CONCLUSIONS: Escitalopram reduces anxiety symptoms, and pharmacogenetics variables influence the trajectory and magnitude of improvement. Variation in CYP2C19 metabolism accounts for significant differences in escitalopram pharmacokinetics, raising the possibility that CYP2C19 phenotype should be considered when prescribing escitalopram. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02818751.


Assuntos
Ansiolíticos/uso terapêutico , Transtornos de Ansiedade/tratamento farmacológico , Citalopram/uso terapêutico , Inibidores de Captação de Serotonina/uso terapêutico , Adolescente , Área Sob a Curva , Criança , Citalopram/análogos & derivados , Citalopram/sangue , Citalopram/farmacocinética , Citocromo P-450 CYP2C19/genética , Citocromo P-450 CYP2C19/metabolismo , Método Duplo-Cego , Feminino , Humanos , Masculino , Escalas de Graduação Psiquiátrica , Inibidores de Captação de Serotonina/sangue , Inibidores de Captação de Serotonina/farmacocinética , Resultado do Tratamento
6.
Cell Metab ; 31(5): 909-919.e8, 2020 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-32275862

RESUMO

Perturbations in carbohydrate, lipid, and protein metabolism contribute to obesity-induced type 2 diabetes (T2D), though whether alterations in ketone body metabolism influence T2D pathology is unknown. We report here that activity of the rate-limiting enzyme for ketone body oxidation, succinyl-CoA:3-ketoacid-CoA transferase (SCOT/Oxct1), is increased in muscles of obese mice. We also found that the diphenylbutylpiperidine pimozide, which is approved to suppress tics in individuals with Tourette syndrome, is a SCOT antagonist. Pimozide treatment reversed obesity-induced hyperglycemia in mice, which was phenocopied in mice with muscle-specific Oxct1/SCOT deficiency. These actions were dependent on pyruvate dehydrogenase (PDH/Pdha1) activity, the rate-limiting enzyme of glucose oxidation, as pimozide failed to alleviate hyperglycemia in obese mice with a muscle-specific Pdha1/PDH deficiency. This work defines a fundamental contribution of enhanced ketone body oxidation to the pathology of obesity-induced T2D, while suggesting pharmacological SCOT inhibition as a new class of anti-diabetes therapy.

7.
Contemp Clin Trials ; 91: 105976, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32147571

RESUMO

BACKGROUND: Cancer-related fatigue is a significant problem and is associated with poor quality of life. Behavioral interventions include exercise and cognitive-behavioral therapy, which survivors may be unwilling or unable to adopt. Pharmacologic interventions (e.g., selective serotonin reuptake inhibitors) have been disappointing. One potential therapy is the antidepressant bupropion, a norepinephrine-dopamine reuptake inhibitor that targets both inflammation and the hypothalamic-pituitary-adrenal axis. The current study is intended to provide a rigorous test of the efficacy and tolerability of bupropion for cancer-related fatigue. METHODS: A randomized, double-blind, placebo-controlled trial will examine the effects of bupropion on cancer-related fatigue. The trial will be conducted nationwide through the University of Rochester Medical Center (URMC) National Cancer Institute Community Oncology Research Program (NCORP). Disease-free breast cancer survivors (n = 422) who completed chemotherapy and/or radiotherapy 12-60 months previously and report significant fatigue will be randomized 1:1 to receive bupropion (300 mg/day) or placebo. Outcomes will be assessed at baseline and the 12-week follow-up. The primary outcome, fatigue, will be measured with the Functional Assessment of Chronic Illness Therapy - Fatigue (FACIT-F). Secondary outcomes include quality of life, depression, and drug tolerability. Exploratory outcomes include cognition and symptomatology. Potential biological mechanisms and genetic moderators of cancer-related fatigue will also be explored. DISCUSSION: This study is the first placebo-controlled trial to our knowledge to evaluate bupropion for cancer-related fatigue. Positive results could revolutionize the treatment of cancer-related fatigue, as bupropion is safe, inexpensive, widely-available, and may be more tolerable and acceptable for many patients than current, limited treatment options.

8.
Clin Cancer Res ; 26(12): 2986-2996, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32098767

RESUMO

PURPOSE: To determine if the degree of estrogen suppression with aromatase inhibitors (AI: anastrozole, exemestane, letrozole) is associated with efficacy in early-stage breast cancer, and to examine for differences in the mechanism of action between the three AIs. EXPERIMENTAL DESIGN: Matched case-control studies [247 matched sets from MA.27 (anastrozole vs. exemestane) and PreFace (letrozole) trials] were undertaken to assess whether estrone (E1) or estradiol (E2) concentrations after 6 months of adjuvant therapy were associated with risk of an early breast cancer event (EBCE). Preclinical laboratory studies included luciferase activity, cell proliferation, radio-labeled ligand estrogen receptor binding, surface plasmon resonance ligand receptor binding, and nuclear magnetic resonance assays. RESULTS: Women with E1 ≥1.3 pg/mL and E2 ≥0.5 pg/mL after 6 months of AI treatment had a 2.2-fold increase in risk (P = 0.0005) of an EBCE, and in the anastrozole subgroup, the increase in risk of an EBCE was 3.0-fold (P = 0.001). Preclinical laboratory studies examined mechanisms of action in addition to aromatase inhibition and showed that only anastrozole could directly bind to estrogen receptor α (ERα), activate estrogen response element-dependent transcription, and stimulate growth of an aromatase-deficient CYP19A1-/- T47D breast cancer cell line. CONCLUSIONS: This matched case-control clinical study revealed that levels of estrone and estradiol above identified thresholds after 6 months of adjuvant anastrozole treatment were associated with increased risk of an EBCE. Preclinical laboratory studies revealed that anastrozole, but not exemestane or letrozole, is a ligand for ERα. These findings represent potential steps towards individualized anastrozole therapy.

9.
Drug Metab Dispos ; 48(3): 169-175, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31888882

RESUMO

Chronic administration of efavirenz is associated with decreased serum bilirubin levels, probably through induction of UGT1A1 We assessed the impact of efavirenz monotherapy and UGT1A1 phenotypes on total, conjugated, and unconjugated serum bilirubin levels in healthy volunteers. Healthy volunteers were enrolled into a clinical study designed to address efavirenz pharmacokinetics, drug interactions, and pharmacogenetics. Volunteers received multiple oral doses (600 mg/day for 17 days) of efavirenz. Serum bilirubin levels were obtained at study entry and 1 week after completion of the study. DNA genotyping was performed for UGT1A1 [*80 (C>T), *6 (G>A), *28 (TA7), *36 (TA5), and *37 (TA8)] and for SLCO1B1 [*5 (521T>C) and *1b (388A>G] variants. Diplotype predicted phenotypes were classified as normal, intermediate, and slow metabolizers. Compared with bilirubin levels at screening, treatment with efavirenz significantly reduced total, conjugated, and unconjugated bilirubin. After stratification by UGT1A1 phenotypes, there was a significant decrease in total bilirubin among all phenotypes, conjugated bilirubin among intermediate metabolizers, and unconjugated bilirubin among normal and intermediate metabolizers. The data also show that UGT1A1 genotype predicts serum bilirubin levels at baseline, but this relationship is lost after efavirenz treatment. SLCO1B1 genotypes did not predict bilirubin levels at baseline or after efavirenz treatment. Our data suggest that efavirenz may alter bilirubin disposition mainly through induction of UGT1A1 metabolism and efflux through multidrug resistance-associated protein 2. SIGNIFICANCE STATEMENT: Efavirenz likely alters the pharmacokinetics of coadministered drugs, potentially causing lack of efficacy or increased adverse effects, as well as the disposition of endogenous compounds relevant in homeostasis through upregulation of UGT1A1 and multidrug resistance-associated protein 2. Measurement of unconjugated and conjugated bilirubin during new drug development may provide mechanistic understanding regarding enzyme and transporters modulated by the new drug.

10.
Clin Pharmacol Ther ; 107(5): 1200-1208, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31675437

RESUMO

In a randomized, crossover pharmacokinetic study in healthy volunteers (N = 14), a single dose of 2 g probenecid (PRO)-boosted 600 mg tenofovir disoproxil fumarate (TDF)/400 mg emtricitabine (FTC) (test (T) +PRO) was compared with the current on-demand HIV preexposure prophylaxis from the IPERGAY study (a 600 mg TDF/400 mg FTC on day 1 and 300 mg TDF/200 mg FTC on days 2 and 3) (control, C IPERGAY). PRO increased mean single-dose area under the plasma concentration-time curve extrapolated to infinity (AUC0-∞,SD ) of tenofovir (TFV) and FTC by 61% and 68%, respectively. The TFV-diphosphate (TFV-DP) concentrations in peripheral blood mononuclear cells were higher (~30%) at 24 hours in T +PRO but then fell significantly lower (~40%) at 72 hours compared with C IPERGAY. The interaction between FTC and PRO was unexpected and novel. Further study is needed to determine if this PRO-boosted TDF/FTC regimen would be clinically effective.

11.
CPT Pharmacometrics Syst Pharmacol ; 9(1): 40-47, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31749296

RESUMO

Multiple doses of tenofovir disoproxil fumarate (TDF) together with emtricitabine is effective for HIV preexposure prophylaxis (PrEP). TDF is converted to tenofovir (TFV) in circulation, which is subsequently cleared via tubular secretion by organic ion transporters (OATs; OAT1 and OAT3). Using in vitro kinetic parameters for TFV and the OAT1 and OAT3 inhibitor probenecid, a bottom-up physiologically-based pharmacokinetic model was successfully developed for the first time that accurately describes the probenecid-TFV interaction. This model predicted an increase in TFV plasma exposure by 60%, which was within 15% of the observed clinical pharmacokinetic data, and a threefold decrease in renal cells exposure following coadministration of a 600 mg TDF dose with 2 g probenecid. When compared with multiple-dose regimens, a single-dose probenecid-boosted TDF regimen may be effective for HIV PrEP and improve adherence and safety by minimizing TFV-induced nephrotoxicity by reducing TFV accumulation in renal cells.

12.
Clin Transl Sci ; 12(6): 657-666, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31339646

RESUMO

We investigated the effect of efavirenz on the activities of cytochrome P450 (CYP)1A2, CYP2A6, xanthine oxidase (XO), and N-acetyltransferase 2 (NAT2), using caffeine as a probe. A single 150 mg oral dose of caffeine was administered to healthy volunteers (n = 58) on two separate occasions; with a single 600 mg oral dose of efavirenz and after treatment with 600 mg/day efavirenz for 17 days. Caffeine and its metabolites in plasma and urine were quantified using liquid chromatography/tandem-mass spectrometry. DNA was genotyped for CYP2B6*4 (785A>G), CYP2B6*9 (516G>T), and CYP2B6*18 (983T>C) alleles using TaqMan assays. Relative to single-dose efavirenz treatment, multiple doses of efavirenz decreased CYP1A2 (by 38%) and increased CYP2A6 (by 85%) activities (P < 0.05); XO and NAT2 activities were unaffected. CYP2B6*6*6 genotype was associated with lower CYP1A2 activity following both single and multiple doses of efavirenz. No similar association was noted for CYP2A6 activity. This is the first report showing that efavirenz reduces hepatic CYP1A2 and suggesting chronic efavirenz exposure likely enhances the elimination of CYP2A6 substrates. This is also the first to report the extent of efavirenz-CYP1A2 interaction may be efavirenz exposure-dependent and CYP2B6 genotype-dependent.


Assuntos
Benzoxazinas/farmacologia , Citocromo P-450 CYP1A2/metabolismo , Citocromo P-450 CYP2A6/metabolismo , Indutores do Citocromo P-450 CYP2B6/farmacologia , Citocromo P-450 CYP2B6/genética , Inibidores da Transcriptase Reversa/farmacologia , Adolescente , Adulto , Alquinos , Ciclopropanos , Citocromo P-450 CYP2B6/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Adulto Jovem
13.
Pharmacogenomics ; 20(8): 571-580, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31190621

RESUMO

Aim: This study tested for associations between SLCO1B1 polymorphisms and circulating estrogen levels in women with breast cancer treated with letrozole or exemestane. Patients & methods: Postmenopausal women with hormone-receptor positive breast cancer were genotyped for SLCO1B1*5 (rs4149056) and rs10841753. Pretreatment and on-treatment plasma estrogens and aromatase inhibitor (AI) concentrations were measured. Regression analyses were performed to test for pharmacogenetic associations with estrogens and drug concentrations. Results: SLCO1B1*5 was associated with elevated pretreatment estrone sulfate and an increased risk of detectable estrone concentrations after 3 months of AI treatment. Conclusion: These findings suggest SLCO1B1 polymorphisms may have an effect on estrogenic response to AI treatment, and therefore may adversely impact the anticancer effectiveness of these agents.


Assuntos
Androstadienos/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Letrozol/administração & dosagem , Transportador 1 de Ânion Orgânico Específico do Fígado/genética , Androstadienos/efeitos adversos , Inibidores da Aromatase/administração & dosagem , Inibidores da Aromatase/efeitos adversos , Neoplasias da Mama/sangue , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Receptor alfa de Estrogênio/genética , Estrogênios/sangue , Feminino , Genótipo , Humanos , Letrozol/efeitos adversos , Pessoa de Meia-Idade , Farmacogenética , Polimorfismo Genético , Tamoxifeno/administração & dosagem
14.
Clin Pharmacol Ther ; 106(4): 726-733, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31006110

RESUMO

The HIV type-1 nonnucleoside reverse transcriptase inhibitor, efavirenz, is widely used to treat HIV type-1 infection. Efavirenz is predominantly metabolized into inactive metabolites by cytochrome P450 (CYP)2B6, and patients with certain CYP2B6 genetic variants may be at increased risk for adverse effects, particularly central nervous system toxicity and treatment discontinuation. We summarize the evidence from the literature and provide therapeutic recommendations for efavirenz prescribing based on CYP2B6 genotypes.


Assuntos
Benzoxazinas/farmacologia , Citocromo P-450 CYP2B6/genética , Infecções por HIV , HIV-1 , Testes Farmacogenômicos/métodos , Alquinos , Fármacos Anti-HIV/farmacologia , Ciclopropanos , Infecções por HIV/tratamento farmacológico , Infecções por HIV/genética , Humanos , Farmacogenética , Guias de Prática Clínica como Assunto
15.
Drug Metab Dispos ; 47(5): 535-544, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30804050

RESUMO

Integrase strand transfer inhibitor (INSTI)-based regimens dominate initial human immunodeficiency virus treatment. Most INSTIs are metabolized predominantly via UDP-glucuronosyltransferases (UGTs). For drugs predominantly metabolized by UGTs, including INSTIs, in vitro data recovered from human liver microsomes (HLMs) alone often underpredict human oral clearance. While several factors may contribute, extrahepatic glucuronidation may contribute to this underprediction. Thus, we comprehensively characterized the kinetics for the glucuronidation of INSTIs (cabotegravir, dolutegravir, and raltegravir) using pooled human microsomal preparations from liver (HLMs), intestine (HIMs), and kidney (HKMs) tissues; human embryonic kidney 293 cells expressing individual UGTs; and recombinant UGTs. In vitro glucuronidation of cabotegravir (HLMs≈HKMs>>>HIMs), dolutegravir (HLMs>HIMs>>HKMs), and raltegravir (HLMs>HKMs>> HIMs) occurred in hepatic and extrahepatic tissues. The kinetic data from expression systems suggested the major enzymes in each tissue: hepatic UGT1A9 > UGT1A1 (dolutegravir and raltegravir) and UGT1A1 (cabotegravir), intestinal UGT1A3 > UGT1A8 > UGT1A1 (dolutegravir) and UGT1A8 > UGT1A1 (raltegravir), and renal UGT1A9 (dolutegravir and raltegravir). Enzymes catalyzing cabotegravir glucuronidation in the kidney and intestine could not be identified unequivocally. Using data from dolutegravir glucuronidation as a prototype, a "bottom-up" physiologically based pharmacokinetic model was developed in a stepwise approach and predicted dolutegravir oral clearance within 4.5-fold (hepatic data only), 2-fold (hepatic and intestinal data), and 32% (hepatic, intestinal, and renal data). These results suggest clinically meaningful glucuronidation of dolutegravir in tissues other than the liver. Incorporation of additional novel mechanistic and physiologic underpinnings of dolutegravir metabolism along with in silico approaches appears to be a powerful tool to accurately predict the clearance of dolutegravir from in vitro data.


Assuntos
Glucuronosiltransferase/metabolismo , Integrases/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular , Criança , Pré-Escolar , Feminino , Células HEK293 , Compostos Heterocíclicos com 3 Anéis/metabolismo , Humanos , Mucosa Intestinal/metabolismo , Rim/metabolismo , Cinética , Fígado/metabolismo , Masculino , Microssomos Hepáticos/metabolismo , Pessoa de Meia-Idade , Oxazinas , Piperazinas , Piridonas/metabolismo , Raltegravir Potássico/metabolismo , Adulto Jovem
16.
Pharmacogenomics ; 20(6): 397-408, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30784356

RESUMO

Background: Tramadol and codeine are metabolized by CYP2D6 and are subject to drug-gene and drug-drug interactions. Methods: This interim analysis examined prescribing behavior and efficacy in 102 individuals prescribed tramadol or codeine while receiving pharmaco-genotyping as part of the INGENIOUS trial (NCT02297126). Results: Within 60 days of receiving tramadol or codeine, clinicians more frequently prescribed an alternative opioid in ultrarapid and poor metabolizers (odds ratio: 19.0; 95% CI: 2.8-160.4) as compared with normal or indeterminate metabolizers (p = 0.01). After adjusting the CYP2D6 activity score for drug-drug interactions, uncontrolled pain was reported more frequently in individuals with reduced CYP2D6 activity (odds ratio: 0.50; 95% CI: 0.25-0.94). Conclusion: Phenoconversion for drug-drug and drug-gene interactions is an important consideration in pharmacogenomic implementation; drug-drug interactions may obscure the potential benefits of genotyping.


Assuntos
Analgésicos Opioides/uso terapêutico , Codeína/uso terapêutico , Interações Medicamentosas/genética , Tramadol/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Citocromo P-450 CYP2D6/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Farmacogenética/métodos , Adulto Jovem
17.
Clin Pharmacol Ther ; 106(1): 219-227, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30648747

RESUMO

Anastrozole is a widely prescribed aromatase inhibitor for the therapy of estrogen receptor positive (ER+) breast cancer. We performed a genome-wide association study (GWAS) for plasma anastrozole concentrations in 687 postmenopausal women with ER+ breast cancer. The top single-nucleotide polymorphism (SNP) signal mapped across SLC38A7 (rs11648166, P = 2.3E-08), which we showed to encode an anastrozole influx transporter. The second most significant signal (rs28845026, P = 5.4E-08) mapped near ALPPL2 and displayed epistasis with the SLC38A7 signal. Both of these SNPs were cis expression quantitative trait loci (eQTL)s for these genes, and patients homozygous for variant genotypes for both SNPs had the highest drug concentrations, the highest SLC38A7 expression, and the lowest ALPPL2 expression. In summary, our GWAS identified a novel gene encoding an anastrozole transporter, SLC38A7, as well as epistatic interaction between SNPs in that gene and SNPs near ALPPL2 that influenced both the expression of the transporter and anastrozole plasma concentrations.


Assuntos
Fosfatase Alcalina/genética , Anastrozol/farmacocinética , Inibidores da Aromatase/farmacocinética , Epistasia Genética/genética , Anastrozol/sangue , Anastrozol/uso terapêutico , Inibidores da Aromatase/sangue , Inibidores da Aromatase/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Cromossomos Humanos Par 16/genética , Cromossomos Humanos Par 2/genética , Feminino , Proteínas Ligadas por GPI/genética , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Polimorfismo de Nucleotídeo Único , Pós-Menopausa , Receptores Estrogênicos/biossíntese
19.
CPT Pharmacometrics Syst Pharmacol ; 7(11): 709-717, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30033622

RESUMO

Drug metabolites (DMs) are critical in pharmacology research areas, such as drug metabolism pathways and drug-drug interactions. However, there is no terminology dictionary containing comprehensive drug metabolite names, and there is no named entity recognition (NER) algorithm focusing on drug metabolite identification. In this article, we developed a novel NER system, DrugMetab, to identify DMs from the PubMed abstracts. DrugMetab utilizes the features characterized from the Part-of-Speech, drug index, and pre/suffix, and determines DMs within context. To evaluate the performance, a gold-standard corpus was manually constructed. In this task, DrugMetab with sequential minimal optimization (SMO) classifier achieves 0.89 precision, 0.77 recall, and 0.83 F-measure in the internal testing set; and 0.86 precision, 0.85 recall, and 0.86 F-measure in the external validation set. We further compared the performance between DrugMetab and whatizitChemical, which was designed for identifying small molecules or chemical entities. DrugMetab outperformed whatizitChemical, which had a lower recall rate of 0.65.


Assuntos
Aprendizado de Máquina , Preparações Farmacêuticas/metabolismo , Algoritmos , Humanos , Armazenamento e Recuperação da Informação , Farmacocinética
20.
Pharmacol Res Perspect ; 6(2): e00386, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29610665

RESUMO

Rifampin is a pleiotropic inducer of multiple drug metabolizing enzymes and transporters. This work utilized a global approach to evaluate rifampin effects on conjugating enzyme gene expression with relevance to human xeno- and endo-biotic metabolism. Primary human hepatocytes from 7 subjects were treated with rifampin (10 µmol/L, 24 hours). Standard methods for RNA-seq library construction, EZBead preparation, and NextGen sequencing were used to measure UDP-glucuronosyl transferase UGT, sulfonyltransferase SULT, N acetyltransferase NAT, and glutathione-S-transferase GST mRNA expression compared to vehicle control (0.01% MeOH). Rifampin-induced (>1.25-fold) mRNA expression of 13 clinically important phase II drug metabolizing genes and repressed (>1.25-fold) the expression of 3 genes (P < .05). Rifampin-induced miRNA expression changes correlated with mRNA changes and miRNAs were identified that may modulate conjugating enzyme expression. NAT2 gene expression was most strongly repressed (1.3-fold) by rifampin while UGT1A4 and UGT1A1 genes were most strongly induced (7.9- and 4.8-fold, respectively). Physiologically based pharmacokinetic modeling (PBPK) was used to simulate the clinical consequences of rifampin induction of CYP3A4- and UGT1A4-mediated midazolam metabolism. Simulations evaluating isolated UGT1A4 induction predicted increased midazolam N-glucuronide exposure (~4-fold) with minimal reductions in parent midazolam exposure (~10%). Simulations accounting for simultaneous induction of both CYP3A4 and UGT1A4 predicted a ~10-fold decrease in parent midazolam exposure with only a ~2-fold decrease in midazolam N-glucuronide metabolite exposure. These data reveal differential effects of rifampin on the human conjugating enzyme transcriptome and potential associations with miRNAs that form the basis for future mechanistic studies to elucidate the interplay of conjugating enzyme regulatory elements.


Assuntos
Hepatócitos/enzimologia , MicroRNAs/genética , Modelos Biológicos , Rifampina/farmacologia , Transcriptoma/efeitos dos fármacos , Xenobióticos/farmacocinética , Arilamina N-Acetiltransferase/genética , Arilsulfotransferase/genética , Células Cultivadas , Perfilação da Expressão Gênica , Glucuronosiltransferase/genética , Hepatócitos/efeitos dos fármacos , Humanos , Desintoxicação Metabólica Fase II , Cultura Primária de Células
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