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1.
Ther Adv Cardiovasc Dis ; 16: 17539447221132908, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36373589

RESUMO

INTRODUCTION: Heart failure (HF) is a syndrome increasing worldwide, and literature shows that the hospitalizations are associated with greater mortality rates. A patient-centered method combined with optimized medical treatment and palliative care may improve HF outcomes, and some advocate a multifaceted approach to achieve a perfect management of chronic HF (CHF). OBJECTIVE: The objective of this study was to present the study protocol of GENICA project which aims to optimize the ambulatory approach of CHF patients, and reduce their re-hospitalization, emergency readmission, and global death rate. DESIGN: Prospective cohort including patients referred to HF consultation and collecting sociodemographic, clinical, and analytical variables among others. The outcomes will be mortality, re-hospitalization, and emergency readmission rates. The association between the independent variables and outcomes will be assessed by logistic regression. Comparison between GENICA patients and controls will be made by χ2 test. Significance at p level of less than 0.05. RESULTS: GENICA will offer a wide range of longitudinal data with evidence that will influence future healthcare of CHF patients at an ambulatory basis. DISCUSSION: GENICA will provide practical evidence of real HF patient's profile and develop workable decision algorithms, which will influence future ambulatory care of CHF. HF patients will be safer at home and will keep stability for longer periods, consuming less health resources and slow the progression of the disease. Being a matched cohort, GENICA benefits from an accuracy similar to that of randomized controlled trials, without the need to perform a rigorous allocation of the intervention. Being prospective there's no problem about response bias. CONCLUSION: CHF should be approached with a multidisciplinary and multifaceted strategy privileging the outpatient setting, including home monitoring, and GENICA is the paramount protocol enabling this. GENICA may come to show health policy makers that the asset is not to divide and rule, but to converge strategies, therapies, and knowledge.


Assuntos
Insuficiência Cardíaca , Telemedicina , Humanos , Readmissão do Paciente , Estudos Prospectivos , Telemedicina/métodos , Insuficiência Cardíaca/terapia , Insuficiência Cardíaca/tratamento farmacológico , Hospitalização
2.
Rev Port Cardiol (Engl Ed) ; 40(5): 329-337, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34187634

RESUMO

Heart failure (HF) is a multifactorial chronic syndrome with progressive increasing incidence causing a huge financial burden worldwide. Remote monitoring should, in theory, improve HF management, but given increasing morbidity and mortality, a question remains: are we monitoring it properly? Device-based home monitoring enables objective and continuous measurement of vital variables and non-invasive devices should be first choice for elderly patients. There is no shortage of literature on the subject, however, most studies were designed to monitor a single variable or class of variables that were not properly assembled and, to the best of our knowledge, there are no large randomized studies about their impact on HF patient management. To overcome this problem, we carefully selected the most critical possible HF decompensating factors to design MONITORIA, a non-invasive device for comprehensive HF home monitoring. MONITORIA stands for MOnitoring Non-Invasively To Overcome mortality Rates of heart Insufficiency on Ambulatory, and in this paper, which is part I of a series of three articles, we discuss the theoretical basis for its design. MONITORIA and its inherent follow-up strategy will optimize HF patient care as it is a promising device, which will essentially adapt innovation not to the disease but rather to the patients.


Assuntos
Insuficiência Cardíaca , Idoso , Insuficiência Cardíaca/diagnóstico , Humanos , Monitorização Fisiológica , Síndrome
3.
Rev Port Cardiol (Engl Ed) ; 40(5): 343-351, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34187636

RESUMO

INTRODUCTION: Heart failure (HF) represents a huge financial and economic burden worldwide. Some authors advocate that remote monitoring should be implemented to improve HF management, but given its increasing incidence, as well as its morbidity and mortality, a question still remains: are we monitoring it properly? There is no shortage of literature on home monitoring devices, however, most of them are designed to monitor an unsuitable array of variables and, to the best of our knowledge, there are no large randomized studies about their impact on morbidity/mortality of HF patients. OBJECTIVE: Description of a novel monitoring device. METHODS: As a solution, we designed MONITORIA (MOnitoring NonInvasively To Overcome mortality Rates of heart Insufficiency on Ambulatory). RESULTS: This is a multimodal device that will provide real time monitoring of vital, electrophysiological, hemodynamic and chemical signs, transthoracic impedance, and physical activity levels. The device is meant to perform continuous analysis and transmission of all data. Significant alterations in a patient's variable will alert the attending physician and, in case of potentially life-threatening situations, the national emergency medical system. The MONITORIA device will, also, have a function that sends shocks or functions as a pacemaker to treat certain arrhythmias/blockades. This function can be activated the very first time the patient utilizes it, based on their risk of sudden cardiac death. DISCUSSION/CONCLUSIONS: MONITORIA is a promising device mostly because it is included in a follow-up program that takes into account a multi-perspective feature of HF development and is based on the real world patient, adapting innovations not to the disease but rather to the patients.


Assuntos
Insuficiência Cardíaca , Marca-Passo Artificial , Arritmias Cardíacas , Serviço Hospitalar de Emergência , Insuficiência Cardíaca/diagnóstico , Humanos , Monitorização Fisiológica
4.
Rev Port Cardiol (Engl Ed) ; 40(5): 343-351, 2021 05.
Artigo em Inglês, Português | MEDLINE | ID: mdl-33888351

RESUMO

INTRODUCTION: Heart failure (HF) represents a huge financial and economic burden worldwide. Some authors advocate that remote monitoring should be implemented to improve HF management, but given its increasing incidence, as well as its morbidity and mortality, a question still remains: are we monitoring it properly? There is no shortage of literature on home monitoring devices, however, most of them are designed to monitor an unsuitable array of variables and, to the best of our knowledge, there are no large randomized studies about their impact on morbidity/mortality of HF patients. OBJECTIVE: Description of a novel monitoring device. METHODS: As a solution, we designed MONITORIA (MOnitoring NonInvasively To Overcome mortality Rates of heart Insufficiency on Ambulatory). RESULTS: This is a multimodal device that will provide real time monitoring of vital, electrophysiological, hemodynamic and chemical signs, transthoracic impedance, and physical activity levels. The device is meant to perform continuous analysis and transmission of all data. Significant alterations in a patient's variable will alert the attending physician and, in case of potentially life-threatening situations, the national emergency medical system. The MONITORIA device will, also, have a function that sends shocks or functions as a pacemaker to treat certain arrhythmias/blockades. This function can be activated the very first time the patient utilizes it, based on their risk of sudden cardiac death. DISCUSSION/CONCLUSIONS: MONITORIA is a promising device mostly because it is included in a follow-up program that takes into account a multi-perspective feature of HF development and is based on the real world patient, adapting innovations not to the disease but rather to the patients.

5.
Rev Port Cardiol (Engl Ed) ; 40(5): 329-337, 2021 05.
Artigo em Inglês, Português | MEDLINE | ID: mdl-33483175

RESUMO

Heart failure (HF) is a multifactorial chronic syndrome with progressive increasing incidence causing a huge financial burden worldwide. Remote monitoring should, in theory, improve HF management, but given increasing morbidity and mortality, a question remains: are we monitoring it properly? Device-based home monitoring enables objective and continuous measurement of vital variables and non-invasive devices should be first choice for elderly patients. There is no shortage of literature on the subject, however, most studies were designed to monitor a single variable or class of variables that were not properly assembled and, to the best of our knowledge, there are no large randomized studies about their impact on HF patient management. To overcome this problem, we carefully selected the most critical possible HF decompensating factors to design MONITORIA, a non-invasive device for comprehensive HF home monitoring. MONITORIA stands for MOnitoring Non-Invasively To Overcome mortality Rates of heart Insufficiency on Ambulatory, and in this paper, which is part I of a series of three articles, we discuss the theoretical basis for its design. MONITORIA and its inherent follow-up strategy will optimize HF patient care as it is a promising device, which will essentially adapt innovation not to the disease but rather to the patients.

6.
J Clin Monit Comput ; 35(5): 1169-1181, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-32889643

RESUMO

Predictions of mortality may help in the selection of patients who benefit from intensive care. Endothelial dysfunction is partially responsible for many of the organic dysfunctions in critical illness. Reactive hyperaemia is a vascular response of the endothelium that can be measured by peripheral arterial tonometry (RH-PAT). We aimed to assess if reactive hyperaemia is affected by critical illness and if it correlates with outcomes. Prospective study with a cohort of consecutive patients admitted to an Intensive Care Unit. RH-PAT was accessed on admission and on the 7th day after admission. Early and late survivors were compared to non-survivors. The effect of RH-PAT variation on late mortality was studied by a logistic regression model. The association between RH-PAT and severity scores and biomarkers of organic dysfunction was investigated by multivariate analysis. 86 patients were enrolled. Mean ln(RHI) on admission was 0.580 and was significantly lower in patients with higher severity scores (p < 0.01) and early non-survivors (0.388; p = 0.027). The model for prediction of early-mortality estimated that each 0.1 decrease in ln(RHI) increased the odds for mortality by 13%. In 39 patients, a 2nd RH-PAT measurement was performed on the 7th day. The variation of ln(RHI) was significantly different between non-survivors and survivors (- 24.2% vs. 63.9%, p = 0.026). Ln(RHI) was significantly lower in patients with renal and cardiovascular dysfunction (p < 0.01). RH-PAT is correlated with disease severity and seems to be an independent marker of early mortality, cardiovascular and renal dysfunctions. RH-PAT variation predicts late mortality. There appears to be an RH-PAT impairment in the acute phase of severe diseases that may be reversible and associated with better outcomes.


Assuntos
Estado Terminal , Hiperemia , Endotélio Vascular , Humanos , Manometria , Insuficiência de Múltiplos Órgãos/diagnóstico , Prognóstico , Estudos Prospectivos
7.
Rev Port Cardiol (Engl Ed) ; 37(2): 179-199, 2018 Feb.
Artigo em Inglês, Português | MEDLINE | ID: mdl-29525288

RESUMO

INTRODUCTION AND OBJECTIVES: The importance of sodium channels for the normal electrical activity of the heart is emphasized by the fact that mutations (inherited or de novo) in genes that encode for these channels or their associated proteins cause arrhythmogenic syndromes such as the Brugada syndrome and the long QT syndrome (LQTS). The aim of this study is to conduct a review of the literature on the mutations in the sodium channel complex responsible for heart disease and the implications of a close relationship between genetics and the clinical aspects of the main cardiac channelopathies, namely at the level of diagnosis, risk stratification, prognosis, screening of family members and treatment. METHODS: The online Pubmed® database was used to search for articles published in this field in indexed journals. The MeSH database was used to define the following query: "Mutation [Mesh] AND Sodium Channels [Mesh] AND Heart Diseases [Mesh]", and articles published in the last 15 years, written in English or Portuguese and referring to research in human beings were included. CONCLUSIONS: In the past few years, significant advances have been made to clarify the genetic and molecular basis of these syndromes. A greater understanding of the underlying pathophysiological mechanisms showed the importance of the relationship between genotype and phenotype and led to progress in the clinical approach to these patients. However, it is still necessary to improve diagnostic capacity, optimize risk stratification, and develop new specific treatments according to the genotype-phenotype binomial.


Assuntos
Cardiomiopatias/genética , Cardiomiopatias/metabolismo , Canalopatias/genética , Canalopatias/metabolismo , Mutação , Canais de Sódio/genética , Algoritmos , Cardiomiopatias/diagnóstico , Canalopatias/diagnóstico , Humanos , Canais de Sódio/fisiologia
8.
Rev Port Cardiol ; 35(11): 601-616, 2016 Nov.
Artigo em Inglês, Português | MEDLINE | ID: mdl-27712930

RESUMO

The Acute Dialysis Quality Initiative consensus conference proposed a classification of cardiorenal syndrome (CRS), aiming for a better delineation of each subtype. Although the exact pathophysiology of type 4 CRS is not completely understood, the mechanisms involved are probably multifactorial. There is growing evidence that oxidative stress is a major connector in the development and progression of type 4 CRS. Giving its complexity, poor prognosis and increasing incidence, type 4 CRS is becoming a significant public health problem. Patients with chronic kidney disease are particularly predisposed to cardiac dysfunction, due to the high prevalence of traditional cardiovascular risk factors in this population, but the contribution of risk factors specific to chronic kidney disease should also be taken into account. Much remains to be elucidated about type 4 CRS: despite progress over the last decade, there are still significant questions regarding its pathophysiology and there is as yet no specific therapy. A better understanding of the mechanisms involved may provide potential targets for intervention. The present review will provide a brief description of the definition, epidemiology, diagnosis, prognosis, biomarkers and management strategies of type 4 CRS, and the pathophysiological mechanisms and risk factors presumably involved in its development will be particularly highlighted.


Assuntos
Síndrome Cardiorrenal/classificação , Síndrome Cardiorrenal/etiologia , Doenças Cardiovasculares/etiologia , Humanos , Fatores de Risco
9.
Eur J Clin Pharmacol ; 70(9): 1059-71, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24925090

RESUMO

BACKGROUND AND OBJECTIVES: Opicapone is a novel third generation catechol-O-methyltransferase (COMT) inhibitor. The purpose of this study was to compare the levodopa pharmacokinetic profile throughout a day driven by the COMT inhibition either following repeated doses of opicapone or concomitant administration with entacapone. METHODS: A randomized, double-blind, gender-balanced, parallel-group study was performed in 4 groups of 20 healthy subjects each. Four subjects in each group received placebo during the entire study. Sixteen subjects in one group received placebo once daily for 11 days and on day 12, 200 mg entacapone concomitantly with each levodopa/carbidopa dose (three times separated by a 5-h interval). Sixteen subjects in each of the remaining three groups received respectively 25, 50, and 75 mg opicapone once daily for 11 days and on day 12, placebo concomitantly with each levodopa/carbidopa dose. RESULTS: Levodopa minimum plasma concentration (Cmin) for each levodopa/carbidopa dose and for the mean of all levodopa/carbidopa doses increased substantially with all active treatments (entacapone and opicapone) when compared to the control group (placebo), with values ranging from 1.7-fold (200 mg entacapone) to 3.3-fold (75 mg opicapone). No statistical difference was found for levodopa peak of systemic exposure (as assessed by maximum observed plasma concentration (Cmax)) between all active treatments and placebo. A significant increase in the levodopa extent of systemic exposure (as assessed by concentration-time curve (AUC)) occurred with all opicapone treatments in relation to placebo. No statistical difference was found for levodopa AUC when entacapone was compared to placebo. When compared to entacapone, both 50 and 75 mg opicapone presented a significant increase for the levodopa AUC. All active treatments significantly inhibited both peak (as assessed by Emax) and extent (as assessed by effect-time curve (AUEC)) of the COMT activity in relation to placebo. When compared to entacapone, all opicapone treatments significantly decreased the extent (AUEC) of the COMT activity due to a long-lasting and sustained effect. The tolerability profile was favorable for all active treatments. CONCLUSION: Opicapone, a novel third generation COMT inhibitor, when compared to entacapone, provides a superior response upon the bioavailability of levodopa associated to more pronounced, long-lasting, and sustained COMT inhibition. The tolerability profile was favorable. On the basis of the results presented in this study and along with the earlier pharmacology studies, it is anticipated that opicapone adjunct therapy at the dosages of 25 and 50 mg will provide an enhancement in levodopa availability that will translate into clinical benefit for Parkinson's disease patients.


Assuntos
Antiparkinsonianos/farmacocinética , Inibidores de Catecol O-Metiltransferase/farmacologia , Catecóis/farmacologia , Levodopa/farmacocinética , Nitrilas/farmacologia , Oxidiazóis/farmacologia , Adulto , Antiparkinsonianos/efeitos adversos , Antiparkinsonianos/sangue , Antiparkinsonianos/farmacologia , Área Sob a Curva , Catecol O-Metiltransferase/metabolismo , Inibidores de Catecol O-Metiltransferase/efeitos adversos , Catecóis/efeitos adversos , Método Duplo-Cego , Esquema de Medicação , Interações Medicamentosas , Feminino , Humanos , Levodopa/administração & dosagem , Levodopa/efeitos adversos , Levodopa/sangue , Masculino , Pessoa de Meia-Idade , Nitrilas/efeitos adversos , Oxidiazóis/efeitos adversos , Adulto Jovem
10.
Clin Ther ; 35(12): 1983-96, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24296323

RESUMO

BACKGROUND: Etamicastat is a dopamine ß-hydroxylase (DßH) inhibitor currently in clinical development for the treatment of hypertension and heart failure. OBJECTIVE: This study assessed the tolerability, pharmacokinetics, and pharmacodynamics of etamicastat in patients with arterial hypertension. METHODS: This randomized, double-blind, placebo-controlled study was conducted in male patients aged between 18 and 65 years with mild to moderate hypertension. Participants received once-daily doses of etamicastat 50, 100, or 200 mg or placebo for 10 days. Antihypertensive effect was assessed by 24-hour ambulatory blood pressure monitoring (ABPM). RESULTS: The study enrolled 23 male volunteers, with ages between 49 and 64 years. There were no serious adverse events reported. All adverse events were mild to moderate in intensity and resolved without sequelae. Etamicastat Tmax was 1 hour postdose, and mean t½ was 19 to 28 hours following repeated administration. Etamicastat underwent N-acetylation by N-acetyltransferase 2 (NAT2), forming the metabolite BIA 5-961. Following repeated administration, mean etamicastat AUC was 2- to 3-fold greater in poor acetylators than in rapid acetylators. Approximately 50% of the etamicastat dose was recovered in urine-30% as unchanged etamicastat and 20% as BIA 5-961. Dose-dependent decreases in systolic and diastolic blood pressure were observed after 10 days of treatment. The mean (95% CI) decreases versus placebo in nighttime SBP were statistically significant with all 3 etamicastat doses (50 mg, -11.66 mm Hg [-21.57 to -1.76; P < 0.05]; 100 mg, -14.92 mm Hg [-24.98 to -4.87; P < 0.01]; and 200 mg, -13.62 mm Hg [-22.29 to -3.95; P < 0.01]). CONCLUSIONS: Etamicastat was well tolerated and showed a pharmacokinetic profile consistent with a once-daily regimen. NAT2 phenotype markedly affected the pharmacokinetics. The antihypertensive effect of etamicastat, assessed by 24-hour ABPM, was dose dependent up to 100 mg. The assessment of etamicastat as a novel antihypertensive therapy requires further study in broader populations. EudraCT trial registration 2008-002789-09.


Assuntos
Anti-Hipertensivos/efeitos adversos , Anti-Hipertensivos/farmacocinética , Benzopiranos/efeitos adversos , Benzopiranos/farmacocinética , Pressão Sanguínea/efeitos dos fármacos , Dopamina beta-Hidroxilase/antagonistas & inibidores , Hipertensão/tratamento farmacológico , Imidazóis/efeitos adversos , Imidazóis/farmacocinética , Adolescente , Adulto , Idoso , Anti-Hipertensivos/administração & dosagem , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismo , Benzopiranos/administração & dosagem , Monitorização Ambulatorial da Pressão Arterial , Relação Dose-Resposta a Droga , Método Duplo-Cego , Frequência Cardíaca/efeitos dos fármacos , Humanos , Hipertensão/fisiopatologia , Imidazóis/administração & dosagem , Isoenzimas/genética , Isoenzimas/metabolismo , Masculino , Pessoa de Meia-Idade , Fenótipo , Adulto Jovem
11.
Epilepsia ; 54(8): 1453-61, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23758485

RESUMO

PURPOSE: Investigate the pharmacokinetics of once-daily (QD; 900 mg) and twice-daily (BID; 450 mg) regimens of eslicarbazepine acetate (ESL) and BID (450 mg) regimen of oxcarbazepine (OXC) at steady state in healthy volunteers. METHODS: Single-center, open-label, randomized, three-way (n = 12) crossover studies in healthy volunteers. KEY FINDINGS: Mean eslicarbazepine Cmax,ss (in µm) following ESL QD (87.3) was 33.3% higher (p < 0.05) compared to ESL BID (65.5) and 82.1% higher (p < 0.05) compared to OXC BID (48.0). The mean area under the curve (AUC)ss,0-τ (in µmol h/L) following the last dose of an 8-day repeated dosing was 1156.3, 1117.6, and 968.4 for ESL QD, ESL BID, and OXC BID, respectively. The ratio eslicarbazepine plasma exposure (µmol h/L) to ESL daily-dose (µmol) was 0.381 (1156.3:3037.3), 0.368 (1117.6:3037.3), and 0.271 (968.4:3567.6) for ESL-QD, ESL-BID, and OXC-BID, respectively, which translates into a 40.6% increase in the ability of ESL-QD compared to OXC-BID to deliver into the plasma their major active entity eslicarbazepine. The extent of plasma exposure to ESL minor metabolites: (R)-licarbazepine and oxcarbazepine after ESL-QD was 71.5% and 61.1% lower, respectively, than after OXC-BID. Twenty, 24 and 38 treatment emergent adverse events were reported with ESL-QD, ESL-BID, and OXC-BID, respectively. SIGNIFICANCE: ESL-QD resulted in 33.3% higher peak plasma concentration (Cmax,ss ) of eslicarbazepine and similar extent of plasma exposure (AUCss,0-τ ) when compared to ESL-BID, which may contribute to the efficacy profile reported with once-daily ESL. In comparison to OXC-BID, administration of ESL-QD resulted in 40.6% increase in the delivery of eslicarbazepine into the plasma as well as a significantly lower systemic exposure to (R)-licarbazepine and oxcarbazepine.


Assuntos
Anticonvulsivantes/farmacocinética , Carbamazepina/análogos & derivados , Dibenzazepinas/farmacocinética , Adulto , Anticonvulsivantes/sangue , Anticonvulsivantes/química , Anticonvulsivantes/urina , Área Sob a Curva , Carbamazepina/sangue , Carbamazepina/química , Carbamazepina/farmacocinética , Carbamazepina/urina , Cromatografia Líquida de Alta Pressão , Estudos Cross-Over , Dibenzazepinas/sangue , Dibenzazepinas/química , Dibenzazepinas/urina , Relação Dose-Resposta a Droga , Eletrocardiografia , Eletroquímica , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Oxcarbazepina , Fatores de Tempo
12.
Epilepsy Res ; 105(3): 368-76, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23570863

RESUMO

OBJECTIVE: To investigate the effect of once-daily (QD) eslicarbazepine acetate (ESL) 800 mg and 1,200 mg administration on pharmacokinetics of a combined ethinylestradiol/levonorgestrel oral contraceptive (OC) in women of childbearing potential. METHODS: Two two-way, crossover, two-period, randomized, open-label studies were performed in 20 healthy female subjects, each. In one period (ESL+OC period), subjects received ESL 800 mg QD in one study and ESL 1200 mg QD in the other study, for 15 days; concomitantly with the Day 14 ESL dose, an oral single dose of 30 µg ethinylestradiol and 150 µg levonorgestrel was administered. In the other period (OC alone), a single dose of 30 µg ethinylestradiol and 150 µg levonorgestrel was administered. Three weeks or more separated the periods. An analysis of variance (ANOVA) was used to test for differences between pharmacokinetic parameters of 30 µg ethinylestradiol and 150 µg levonorgestrel following ESL+OC and OC alone, and 90% confidence intervals (90%CI) for the ESL+OC/OC alone geometric mean ratio (GMR) were calculated. RESULTS: ESL significantly decreased the systemic exposure to both ethinylestradiol and levonorgestrel. GMR (90%CI) for AUC0-24 of ethinylestradiol were 68% (64%; 71%) following 1,200 mg ESL and 75% (71%; 79%) following 800 mg ESL. GMR (90%CI) for AUC0-24 of levonorgestrel were 76% (68%; 86%) following 1,200 mg ESL and 89% (82%; 97%) following 800 mg ESL. CONCLUSIONS: A clinically relevant dose-dependent effect of ESL administration on the pharmacokinetics of ethinylestradiol and levonorgestrel was observed. Therefore, to avoid inadvertent pregnancy, women of childbearing potential should use other adequate methods of contraception during treatment with ESL, and, in case ESL treatment is discontinued, until CYP3A4 activity returns to normal.


Assuntos
Anticoncepcionais Femininos/farmacocinética , Dibenzazepinas/farmacocinética , Levanogestrel/farmacocinética , Linestrenol/farmacocinética , Bloqueadores do Canal de Sódio Disparado por Voltagem/farmacocinética , Administração Oral , Análise de Variância , Anticoncepcionais Femininos/administração & dosagem , Anticoncepcionais Femininos/sangue , Estudos Cross-Over , Dibenzazepinas/sangue , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Feminino , Humanos , Levanogestrel/administração & dosagem , Levanogestrel/sangue , Linestrenol/administração & dosagem , Linestrenol/sangue , Fatores de Tempo , Bloqueadores do Canal de Sódio Disparado por Voltagem/sangue
13.
J Clin Pharmacol ; 52(2): 222-33, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21415284

RESUMO

This study investigated the effect of eslicarbazepine acetate (ESL) on cardiac repolarization in healthy adult volunteers. A randomized, placebo/active-controlled, 4-period crossover study was conducted in 67 participants. In 3 periods, participants received once-daily doses of ESL 1200 mg, ESL 2400 mg, and placebo for 5 days; in 1 period, participants received placebo on days 1 to 4 and a 400-mg moxifloxacin single dose on day 5. In each period, 24-hour 12-lead Holter monitoring was performed on days -;1 (baseline) and 5. There was no clinically relevant effect of ESL 1200 mg and 2400 mg versus placebo on cardiac depolarization or repolarization as measured by the QRS or QTc intervals, respectively. Mean PR interval increased following ESL 1200 mg and 2400 mg, but there was no participant with a PR interval above the upper limit of the normal range (200 ms). The upper bound of the 95% confidence interval for the placebo-corrected change from baseline of the individually corrected QT interval (QTcI) following administration of ESL 1200 mg and ESL 2400 mg was <10 ms at every time point. Moxifloxacin caused an increase in QTcI above the 10-ms threshold for clinical significance at several time points, demonstrating assay sensitivity. It is concluded that administration of ESL 1200 mg and ESL 2400 mg did not induce a clinically significant prolongation of the QTcI interval.


Assuntos
Anticonvulsivantes/farmacologia , Dibenzazepinas/farmacologia , Eletrocardiografia Ambulatorial/efeitos dos fármacos , Coração/efeitos dos fármacos , Adolescente , Adulto , Anticonvulsivantes/sangue , Anticonvulsivantes/farmacocinética , Estudos Cross-Over , Dibenzazepinas/sangue , Dibenzazepinas/farmacocinética , Método Duplo-Cego , Feminino , Voluntários Saudáveis , Coração/fisiologia , Humanos , Síndrome do QT Longo , Masculino , Pessoa de Meia-Idade , Adulto Jovem
14.
J Clin Pharmacol ; 52(2): 156-70, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21343348

RESUMO

The safety, tolerability, pharmacokinetics, and pharmacodynamics of etamicastat (BIA 5-453), a novel dopamine ß-hydroxylase (DßH) inhibitor, were investigated in 10 sequential groups of 8 healthy male subjects under a double-blind, randomized, placebo-controlled design. In each group, 6 subjects received a single dose of etamicastat (2, 10, 20, 50, 100, 200, 400, 600, 900, or 1200 mg) and 2 subjects received placebo. Etamicastat was well tolerated at all dose levels tested. Maximum plasma etamicastat concentrations occurred at 1 to 3 hours postdose. Elimination was biphasic, characterized by a first short early elimination half-life followed by a longer elimination phase of 16 to 20 hours for etamicastat doses of 100 mg and above. A high interindividual variability of pharmacokinetic parameters of etamicastat and its acetylated metabolite was observed. Pharmacogenomic data showed that N-acetyltransferase type 2 (NAT2) phenotype (rapid or slow N-acetylating ability) was a major source of variability. In NAT2 poor acetylators, the area under the plasma concentration-time curve from time zero to the last sampling time at which concentrations were at or above the limit of quantification (AUC0-t ) of etamicastat was twice that observed in rapid acetylators. Consistent with that finding, AUC0-t of the acetylated metabolite was markedly higher in NAT2 rapid acetylators compared with poor acetylators. Inhibition of DßH activity was observed, reaching statistical significance for etamicastat doses of 100 mg and above.


Assuntos
Arilamina N-Acetiltransferase/metabolismo , Benzopiranos , Dopamina beta-Hidroxilase/antagonistas & inibidores , Imidazóis , Acetilação , Adolescente , Adulto , Arilamina N-Acetiltransferase/genética , Benzopiranos/efeitos adversos , Benzopiranos/sangue , Benzopiranos/farmacocinética , Benzopiranos/farmacologia , Dopamina beta-Hidroxilase/sangue , Método Duplo-Cego , Voluntários Saudáveis , Humanos , Imidazóis/efeitos adversos , Imidazóis/sangue , Imidazóis/farmacocinética , Imidazóis/farmacologia , Isoenzimas/genética , Masculino , Pessoa de Meia-Idade , Fenótipo , Adulto Jovem
15.
Clin Ther ; 33(6): 776-91, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21704242

RESUMO

BACKGROUND: Etamicastat is a new dopamine-ß-hydroxylase (DßH) inhibitor currently in clinical development for the treatment of hypertension and heart failure. OBJECTIVES: To evaluate the pharmacokinetics and tolerability of etamicastat after single and repeated administration in elderly subjects (aged ≥65 years) relative to young adult healthy controls (aged 18-45 years). METHODS: This was a single-center, open-label, parallel-group study in young male adults (n = 13; mean [SD] age 32.6 [16.4] years; range, 18-44 years; weight 79.0 [16.4] kg; systolic blood pressure 117 [12] mm Hg and diastolic blood pressure 61 [7] mm Hg) and 12 elderly male volunteers (n = 12; age 69.3 [3.3] years; weight 69.2 [9.5] kg; systolic blood pressure 115 [13] mm Hg and diastolic blood pressure 64 [4] mm Hg), conducted in 2 consecutive periods. All subjects were white, except for 1 black elderly subject. In Phase A, subjects received a single dose of 100 mg etamicastat. In Phase B, subjects received 100 mg/d etamicastat for 7 days. The pharmacokinetic parameters of etamicastat and its acetylated metabolite BIA 5-961 were calculated after the single dose of Phase A and the last dose of Phase B. Subjects' N-acetyltransferase type 1 (NAT1) and type 2 (NAT2) genotyping was performed and acetylator status inferred. RESULTS: After a single dose of etamicastat 100 mg, mean (SD) plasma C(max) and plasma AUC(0-∞) were, respectively, 1.3 (0.5) ng/mL/kg and 12.4 (7.8) ng × h/mL/kg in elderly subjects, and 1.3 (0.4) ng/mL/kg and 10.0 (6.6) ng × h/mL/kg in young subjects. At steady-state, C(max) and AUC(0-24) were 1.8 (0.5) ng/mL/kg and 15.0 (6.4) ng × h/mL/kg in elderly subjects, and 1.5 (0.7) ng/mL/kg and 12.5 (6.5) ng × h/mL/kg in young subjects. Elderly/young geometric mean ratios and 90% CIs were, respectively, 0.944 (0.788-1.131) and 1.164 (0.730-1.855) for etamicastat C(max) and AUC(0-∞) after a single dose, and 1.225 (0.960-1.563) and 1.171 (0.850-1.612) for etamicastat C(max) and AUC(0-24) at steady state. Etamicastat steady-state plasma concentrations were reached after 3 to 4 days of dosing. The mean etamicastat accumulation ratio was 1.7 in both age groups. Following etamicastat single dose, mean (SD) BIA 5-961 C(max) and AUC(0-∞) were, respectively, 3.5 (2.1) ng/mL/kg and 28.4 (14.7) ng × h/mL/kg in elderly subjects, and 2.5 (1.5) ng/mL/kg and 16.5 (9.7) in young subjects. At steady state, BIA 5-961, C(max), and AUC(0-24) were 4.3 (2.6) ng/mL/kg and 34.6 (17.6) ng × h/mL/kg in elderly subjects, and 3.1 (2.0) ng/mL/kg and 22.2 (11.8) ng × h/mL/kg in young subjects. Large interindividual variability dependent on the NAT2 acetylator status was found in the pharmacokinetic parameters of etamicastat and BIA 5-961. Systemic exposure to etamicastat was higher and systemic exposure to BIA 5-961 was lower in NAT2 poor metabolizers compared with rapid metabolizers. No effect on heart rate and blood pressure was found in the young group. In the elderly, a decrease of supine blood pressure was observed. Postural changes in blood pressure were unaffected. Four adverse events (AEs) were reported by each group: nasopharyngeal pain, sciatica, asthenia, and back pain the elderly group, and headache (2 cases), insomnia, and myopericarditis by the young group. Myopericarditis led to study discontinuation for this subject and was considered to be of probable viral etiology. All other AEs were mild to moderate in intensity. CONCLUSION: The pharmacokinetic profile of etamicastat was not significantly different in these small groups of healthy young versus elderly adult male volunteers.


Assuntos
Benzopiranos/farmacocinética , Dopamina beta-Hidroxilase/antagonistas & inibidores , Inibidores Enzimáticos/farmacocinética , Imidazóis/farmacocinética , Adolescente , Adulto , Fatores Etários , Idoso , Área Sob a Curva , Arilamina N-Acetiltransferase/genética , Benzopiranos/administração & dosagem , Benzopiranos/efeitos adversos , Esquema de Medicação , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/efeitos adversos , Genótipo , Humanos , Imidazóis/administração & dosagem , Imidazóis/efeitos adversos , Isoenzimas/genética , Masculino , Fatores de Tempo , Adulto Jovem
16.
Drugs R D ; 11(2): 127-36, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21548660

RESUMO

BACKGROUND: Etamicastat is a novel, potent, and reversible peripheral dopamine-ß-hydroxylase inhibitor that has been administered orally at doses up to 600 mg once daily for 10 days to male healthy volunteers and appears to be well tolerated. OBJECTIVE: The aim of this study was to investigate the effect of food on the pharmacokinetics of etamicastat. MATERIAL AND METHODS: A single-center, open-label, randomized, two-way crossover study in 12 healthy male subjects was performed. Subjects were administered a single dose of etamicastat 200 mg following either a standard high-fat and high-calorie content meal (test) or 10 hours of fasting (reference). The statistical method for testing the effect of food on the pharmacokinetic parameters of interest was based upon the 90% confidence interval (CI) for the test/reference geometric mean ratio (GMR). The parameters of interest were maximum plasma concentration (C(max)), area under the plasma concentration-time curve (AUC) from time zero to the last measurable concentration (AUC(last)), and AUC from time zero to infinity (AUC(∞)). Bioequivalence was assumed when the 90% CI fell within the recommended acceptance interval (80, 125). RESULTS: Etamicastat C(max), AUC(last), and AUC(∞) were 229 ng/mL, 1856 ng · h/mL, and 2238 ng · h/mL, respectively, following etamicastat in the fasting, and 166 ng/mL, 1737 ng · h/mL, and 2119 ng · h/mL, respectively, following etamicastat in the fed condition. Etamicastat test/reference GMR was 72.27% (90% CI 64.98, 80.38) for C(max), 93.59% (90% CI 89.28, 98.11) for AUC(last), and 96.47% (90% CI 91.67, 101.53) for AUC(∞). Time to C(max) was prolonged by the presence of food (p < 0.001). The C(max), AUC(last), and AUC(∞) values of the inactive metabolite BIA 5-961 were 275 ng/mL, 1827 ng · h/mL, and 2009 ng · h/mL, respectively, in the fasting, and 172 ng/mL, 1450 ng · h/mL, and 1677 ng · h/mL, respectively, in the fed condition. BIA 5-961 test/reference GMR was 62.42% (90% CI 56.77, 68.63) for C(max), 79.41% (90% CI 56.77, 68.63) for AUC(last), and 83.47% (90% CI 76.62, 90.93) for AUC(∞). A total of six mild to moderate unspecific adverse events were reported by four subjects. There was no clinically significant abnormality in laboratory assessments. CONCLUSION: Etamicastat was well tolerated. The C(max) of etamicastat decreased 28% following oral administration of etamicastat in the presence of food, while AUC remained within the pre-defined acceptance interval. The delay in absorption and decrease in peak exposure of etamicastat is not clinically significant, and therefore etamicastat could be administered without regard to meals. TRIAL REGISTRATION: EudraCT No. 2007-006530-33.


Assuntos
Benzopiranos/farmacocinética , Interações Alimento-Droga/fisiologia , Imidazóis/farmacocinética , Adulto , Área Sob a Curva , Benzopiranos/efeitos adversos , Benzopiranos/sangue , Benzopiranos/metabolismo , Biotransformação/fisiologia , Estudos Cross-Over , Dopamina beta-Hidroxilase/antagonistas & inibidores , Inibidores Enzimáticos/efeitos adversos , Inibidores Enzimáticos/sangue , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacocinética , Privação de Alimentos/fisiologia , Humanos , Imidazóis/efeitos adversos , Imidazóis/sangue , Imidazóis/metabolismo , Masculino , Equivalência Terapêutica , Adulto Jovem
17.
Drugs R D ; 10(4): 225-42, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21171669

RESUMO

BACKGROUND: Activation of the sympathetic nervous system is an important feature in hypertension and congestive heart failure. A strategy for directly modulating sympathetic nerve function is to reduce the biosynthesis of norepinephrine (noradrenaline) via inhibition of dopamine-ß-hydroxylase (DßH). OBJECTIVE: To assess the safety, tolerability, and pharmacokinetics of etamicastat (BIA 5-453), a new DßH inhibitor, following repeated dosing. METHODS: A double-blind, randomized, placebo-controlled study was conducted in healthy young male volunteers. Participants received once-daily doses of placebo or etamicastat 25, 50, 100, 200, 400, or 600 mg, for 10 days. RESULTS: Etamicastat underwent N-acetylation to its metabolite BIA 5-961. Etamicastat and BIA 5-961 maximum concentrations were achieved at 1-3 and 2-4 hours, respectively, after dosing. Elimination half-lives ranged from 18.1 to 25.7 hours for etamicastat and 6.7 to 22.5 hours for BIA 5-961. Both etamicastat and BIA 5-961 followed linear pharmacokinetics. The extent of systemic exposure to etamicastat and BIA 5-961 increased in an approximately dose-proportional manner, and steady-state plasma concentrations were attained up to 9 days of dosing. Etamicastat accumulated in plasma following repeated administration. The mean observed accumulation ratio was 1.3-1.9 for etamicastat and 1.3-1.6 for BIA 5-961. Approximately 40% of the etamicastat dose was recovered in urine in the form of parent compound and BIA 5-961. There was a high variability in pharmacokinetic parameters, attributable to different N-acetyltransferase-2 (NAT2) phenotype. Urinary excretion of norepinephrine decreased following repeated administration of etamicastat. Etamicastat was generally well tolerated. There was no serious adverse event or clinically significant abnormality in clinical laboratory tests, vital signs, or ECG parameters. CONCLUSION: Etamicastat was well tolerated. Etamicastat undergoes N-acetylation, which is markedly influenced by NAT2 phenotype. NAT2 genotyping could be a step toward personalized medicine for etamicastat. TRIAL REGISTRATION: EudraCT No. 2007-004142-33.


Assuntos
Benzopiranos/efeitos adversos , Benzopiranos/farmacocinética , Dopamina beta-Hidroxilase/antagonistas & inibidores , Imidazóis/efeitos adversos , Imidazóis/farmacocinética , Adolescente , Adulto , Arilamina N-Acetiltransferase/genética , Relação Dose-Resposta a Droga , Genótipo , Humanos , Isoenzimas/genética , Masculino , Pessoa de Meia-Idade , Norepinefrina/urina
18.
Curr Med Res Opin ; 26(5): 1097-108, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20225994

RESUMO

OBJECTIVE: To investigate the chronopharmacology of nebicapone, a new catechol-O-methyltransferase (COMT) inhibitor currently being developed for use as an adjunct to levodopa/carbidopa or levodopa/benserazide in the treatment of Parkinson's disease. METHODS: This was a double-blind, randomised, placebo-controlled, parallel-group study. Eighteen Caucasian subjects were randomly assigned to treatment with either nebicapone 100 mg (n = 6), nebicapone 200 mg (n = 6) or placebo (n = 6) at 4-h intervals for 7 days. First dose occurred at 8:00 AM on day 1 and last dose at 8:00 AM on day 8. Blood samples for the determination of plasma drug concentrations of nebicapone and its glucuronidated and methylated metabolites and for the assay of erythrocyte soluble COMT (S-COMT) activity were taken at frequent times following the first and last doses, and before the 8:00 AM and 8:00 PM doses on days 2-7. RESULTS: Three men and three women in each group participated in the study. Mean +/- SD (range) age of study participants was 23.7 +/- 3.1 (21-28) years in the nebicapone 100 mg group, 22.2 +/- 0.4 (22-23) years in the nebicapone 200 mg group and 24.3 +/- 5.4 (18-32) in the placebo group. A circadian variation in the pre-dose nebicapone and nebicapone-glucuronide plasma concentrations was apparent. Both nebicapone and nebicapone-glucuronide levels were lower before the 8 PM dose in comparison to the 8 AM dose, suggesting that the absorption of nebicapone may follow a circadian variation. S-COMT activity showed no circadian variation in the placebo group. Therefore, the S-COMT activity variation found in nebicapone-treated subjects is considered to be due to changes in plasma concentrations of nebicapone, which is consistent with the fact that the pre-dose S-COMT activity was lower at the time at which nebicapone levels were maximal. Four subjects in the nebicapone 100 mg and placebo groups and six subjects in the nebicapone 200 mg group reported at least one adverse event (AE). All AEs were of mild or moderate intensity. Both nebicapone treatment regimens were subjectively well-tolerated, but a clinically relevant elevation in aspartate transaminase was observed in one subject of each nebicapone group. CONCLUSION: Nebicapone showed chronopharmacology in young Caucasian healthy subjects. The clinical impact of the circadian variation in the nebicapone metabolism and activity in Parkinson's disease patients deserves evaluation as it may have implications for drug prescription by modulating the distribution of the total daily dose along the 24-h scale.


Assuntos
Acetofenonas/farmacologia , Inibidores de Catecol O-Metiltransferase , Ritmo Circadiano , Inibidores Enzimáticos/farmacologia , Adolescente , Adulto , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Placebos , Adulto Jovem
19.
Clin Ther ; 32(1): 179-92, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20171423

RESUMO

BACKGROUND: The anticoagulant warfarin, which is administered as a racemic mixture of R- and S-enantiomers, has been reported to interact with other drugs, including some antiepileptics. Eslicarbazepine acetate (ESL) is a once-daily voltage-gated sodium channel blocker that has been developed for the treatment of partial epilepsy and other indications. OBJECTIVE: The aim of this work was to investigate whether multiple-dose administration of ESL had any effect on the steady-state pharmacokinetics and pharmacodynamics of warfarin in healthy volunteers stabilized on warfarin at a subtherapeutic level. METHODS: Subjects received ESL 1200 mg once daily for 8 days concomitantly with racemic warfarin, the dose of which had been individually optimized to a stable prothrombin international normalized ratio (INR) of 1.3 to 1.8 during a previous run-in phase (up to 21 days). Coadministration of ESL and warfarin was followed by a 7-day recovery period when warfarin was again administered alone. The effects of ESL on the steady-state pharmacokinetics of R- and S-warfarin and on the INR were assessed. For the R- and S-warfarin assay, blood sampling was to occur at stage 1 (run-in period), 3 days before starting ESL dosing; stage 2 (combined treatment period), on days 1 and 8 at predose and 0.5, 1, 2, 4, 6, 8, 12, 16, and 24 hours postdose, and on days 4, 6, and 7 at predose; and stage 3 (after the combined treatment period) on days 3, 5, and 7 predose, and on day 8 at 24 hours after the final warfarin dose. For determination of INR, blood sampling was to occur at stage 2 on days 1, 2, 4, 6, 7, and 8 at predose; and at stage 3 on days 1, 3, 5, and 7 at predose and on day 8 at 24 hours after the final warfarin dose. For the assay of the racemic mixture of the S- and the R-enantiomers (eslicarbazepine and R-licarbazepine), blood sampling was to occur at stage 2 on day 8 at predose and 0.5, 1, 2, 4, 6, 8, 12, 16, and 24 hours postdose, and on days 2, 4, 6, and 7 at predose. C(max) and AUC(0-t) were defined as primary pharmacokinetic parameters. Tolerability was evaluated by monitoring adverse events, clinical laboratory safety tests, vital signs, and 12-lead ECG. RESULTS: Of the 15 subjects enrolled, 13 (7 men and 6 women) completed the study. The mean (SD) age was 28.1 (7.3) years (range, 20-42 years), mean weight was 67.3 (10.7) kg (range, 54.0-84.4 kg), and 14 subjects (93.3%) were white. Reductions in S-warfarin C(max) (test:reference geometric means ratio [GMR] = 0.81 [90% CI, 0.76 to 0.86] and in S-warfarin AUC(ss) (test:reference GMR = 0.77 [90% CI, 0.72 to 0.82]) were observed, without any clinically relevant changes in the INR. The mean INR was 1.45 (0.10) when warfarin was used alone in stage 1 (control) and 1.51 (0.25) when ESL was added to warfarin in stage 2. In relation to stage 1, a slight mean INR increase of 4.04% [90% CI, 1.03% to 9.12%] was reported in stage 2. In stage 3, following discontinuation of ESL administration, a change of -5.42% in the INR was found [90% CI, -8.85% to -1.98%]. ESL was not associated with any clinically relevant changes in R-warfarin pharmacokinetic parameters. No deaths, serious adverse events, or discontinuations due to adverse events were noted, and no clinically relevant findings were reported for the other safety variables. During the course of the study, 9 subjects (60%) reported a total of 32 adverse events. Catheter-site ecchymosis, venipuncturesite hematoma, dizziness, vasovagal reaction, and adhesive-tape allergy were the most common adverse events reported. During coadministration of ESL and warfarin, 7 subjects reported a total of 17 adverse events, of which 6 (epigastric discomfort, asthenia, dizziness, lipothymia, irritability, and macular rash) were considered possibly related to treatment; only lipothymia reached moderate intensity, and all symptoms subsided without sequelae after ESL was discontinued. CONCLUSIONS: In this short-term study in healthy subjects, coadministration of warfarin and ESL 1200 mg once daily was associated with a small, but statistically significant, reduction in systemic exposure to S-warfarin. There was no statistically significant effect on R-warfarin pharmacokinetics or on coagulation as measured by the INR. Protocol identifier: UFH/BIA-2093-108.


Assuntos
Anticoagulantes/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Dibenzazepinas/farmacologia , Bloqueadores dos Canais de Sódio/farmacologia , Varfarina/farmacologia , Adulto , Anticoagulantes/administração & dosagem , Anticoagulantes/sangue , Área Sob a Curva , Cromatografia Líquida de Alta Pressão/métodos , Preparações de Ação Retardada , Dibenzazepinas/administração & dosagem , Relação Dose-Resposta a Droga , Feminino , Humanos , Coeficiente Internacional Normatizado , Masculino , Bloqueadores dos Canais de Sódio/administração & dosagem , Espectrometria de Massas em Tandem/métodos , Fatores de Tempo , Varfarina/administração & dosagem , Varfarina/sangue , Adulto Jovem
20.
Clin Ther ; 31(10): 2258-71, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19922897

RESUMO

BACKGROUND: Nebicapone is a reversible catechol-O-methyltransferase (COMT) inhibitor. Coadministration of a COMT inhibitor with levodopa and a dopa-decarboxylase inhibitor (carbidopa or benserazide) increases levodopa exposure and its therapeutic effect. OBJECTIVES: The primary objective of this study was to investigate the effect of nebicapone (50, 100, and 200 mg), compared with placebo, on levodopa pharmacokinetics when coadministered with a single dose of controlled-release levodopa 100 mg/benserazide 25 mg. The secondary objectives were to investigate the effect of nebicapone on the erythrocyte-soluble COMT (S-COMT) activity and on the plasma levels of the levodopa 3-O-methylated metabolite (3-O-methyldopa [3-OMD]). Nebicapone's tolerability was also assessed. METHODS: This was a single-center, Phase I, doubleblind, randomized, placebo-controlled, 4-way crossover study conducted in healthy adult volunteers. Each of the 4 single-dose treatment periods was separated by a washout period of > or = 5 days. During the different treatment periods, subjects received a single dose of controlled-release levodopa 100 mg/benserazide 25 mg concomitantly with nebicapone 50, 100, and 200 mg or placebo. Plasma concentrations of nebicapone, levodopa, and 3-OMD were determined by HPLC. Blood samples (7 mL) for determination of plasma concentrations of levodopa, 3-OMD, and 2258 nebicapone, as well as for the assay of S-COMT activity, were collected in potassium EDTA test tubes at the following times: predose and 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12, 16, and 24 hours postdose. S-COMT activity was assessed as the amount of metanephrine formed by the action of S-COMT on an epinephrine substrate. Spontaneously reported clinical adverse events (AEs) were recorded throughout the study. RESULTS: Sixteen subjects (8 females, 8 males; mean [SD] age, 26.13 [6.29] years; weight, 69.4 [12.4] kg; body mass index, 24.0 [3.0] kg/m2) completed the 4 treatment periods and had data available for pharmacokinetic and pharmacodynamic analyses. Compared with placebo, levodopa C(max) increased 25%, 30%, and 34%, and AUC increased 14%, 37%, and 42% after administration of nebicapone 50, 100, and 200 mg, respectively. After administration of nebicapone 50, 100, and 200 mg, 3-OMD C(max) decreased 44%, 57%, and 58%, and 3-OMD AUC(0-infinity) decreased 33%, 37%, and 45%, respectively, compared with placebo. Extent of exposure to levodopa, as assessed by using AUC(0-t), increased with all doses of nebicapone in relationship to placebo, but the difference did not reach statistical significance. This may be related to a relatively high inter-subject variability: %CVs ranged from 48.0% with nebicapone 100 mg to 66.8% with placebo. Maximum S-COMT inhibition by nebicapone occurred at approximately 1.5 hours postdose and ranged from 57% with nebicapone 50 mg to 74% with nebicapone 200 mg. There was an inverse correlation between plasma concentrations of nebicapone and S-COMT activity; T(max) of nebicapone plasma concentrations and time to occurrence of the maximum inhibition of S-COMT activity appeared to correlate. Nineteen AEs were reported; 8 were assessed by the investigator as possibly related to treatment. All AEs were mild in severity. There were no serious AEs or discontinuations due to AEs. No abnormalities in liver enzyme levels were found. CONCLUSIONS: When administered concomitantly with a single dose of controlled-release levodopa 100 mg/benserazide 25 mg, single doses of nebicapone 50, 100, and 200 mg were well tolerated in these healthy adult volunteers, and dose dependently inhibited S-COMT activity and reduced 3-OMD formation compared with placebo. However, there was no significant difference in levodopa bioavailability.


Assuntos
Acetofenonas/farmacologia , Acetofenonas/farmacocinética , Antiparkinsonianos/farmacologia , Antiparkinsonianos/farmacocinética , Benserazida/farmacologia , Benserazida/farmacocinética , Inibidores de Catecol O-Metiltransferase , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/farmacocinética , Levodopa/farmacologia , Levodopa/farmacocinética , Acetofenonas/administração & dosagem , Adolescente , Adulto , Área Sob a Curva , Benserazida/administração & dosagem , Catecol O-Metiltransferase/sangue , Cromatografia Líquida de Alta Pressão , Estudos Cross-Over , Preparações de Ação Retardada , Método Duplo-Cego , Combinação de Medicamentos , Inibidores Enzimáticos/administração & dosagem , Feminino , Meia-Vida , Humanos , Levodopa/administração & dosagem , Masculino , Pessoa de Meia-Idade , Tirosina/análogos & derivados , Tirosina/sangue , Adulto Jovem
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