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1.
Seizure ; 58: 72-74, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29674237

RESUMO

PURPOSE: Epilepsy is a common neurologic disorder requiring continued treatment during pregnancy. Treatment with antiepileptic drugs (AEDs) is needed for seizure control, but the risk of adverse events has to be minimized for both mother and foetus. Available data on pregnancy and foetal/postnatal outcomes following eslicarbazepine acetate (ESL) exposure via parent is herein presented for the first time. METHODS: ESL's global safety database was reviewed to identify pregnancy cases with exposure to ESL reported up to October 21st, 2017. The EMBASE™ and MEDLINE® databases were searched to identify literature reports of such cases published between May 1st, 2009 and October 21st, 2017. RESULTS: Overall, 91 notifications of pregnancy were identified, of which 79 involved ESL exposure: 28 during clinical trials and 51 from 8-years of post-marketing surveillance. Thirty pregnancies resulted in live birth without congenital anomalies; in 25 pregnancies the outcome was ongoing and 3 was unknown; 18 cases resulted in abortion (10 spontaneous and 8 induced) and congenital anomalies were identified in 5 cases (no clear relationship with ESL was established). ESL was used concomitantly to other AEDs in 11 of the 15 pregnancies for which the outcome was spontaneous abortion and congenital anomaly. Literature review did not yield additional information. CONCLUSIONS: Available data are insufficient to draw conclusions regarding ESL use during pregnancy. Although no particular safety problem was identified, ESL exposure during pregnancy will continue to be monitored and evaluated.


Assuntos
Anticonvulsivantes/uso terapêutico , Dibenzazepinas/uso terapêutico , Epilepsia/complicações , Epilepsia/tratamento farmacológico , Complicações na Gravidez/tratamento farmacológico , Anticonvulsivantes/efeitos adversos , Dibenzazepinas/efeitos adversos , Feminino , Humanos , Gravidez , Resultado da Gravidez
2.
Epilepsy Behav ; 72: 127-134, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28575761

RESUMO

OBJECTIVE: To assess the safety and efficacy of once-daily (QD) adjunctive eslicarbazepine acetate (ESL). METHODS: This post-hoc pooled analysis of three randomized, placebo-controlled trials (2093-301, -302, -304) involved adults with refractory partial-onset seizures (POS) receiving 1-3 antiepileptic drugs (AEDs). All studies included 8-week baseline, 2-week titration, and 12-week maintenance periods. Patients were randomized equally to placebo, ESL 400mg (studies 301, 302), 800mg, or 1200mg QD. The primary endpoint was standardized seizure frequency (SSF; per 4weeks); secondary endpoints included responder rates (maintenance period), and incidence of treatment-emergent adverse events (TEAEs), TEAEs leading to discontinuation, serious AEs (SAEs), and deaths. RESULTS: The safety and efficacy analysis populations totaled 1447 and 1410 patients, respectively. SSF was significantly reduced versus placebo with ESL 800mg (p=0.0001) and 1200mg (p<0.0001) but not 400mg (p=0.81). There were no significant interactions between treatment effect and age, gender, race/ethnicity, geographic region, epilepsy duration, or concomitant AED use. Incidences of TEAEs and TEAEs leading to discontinuation increased with ESL dose. Incidences of the most frequent TEAEs were lower for patients who initiated dosing at 400 versus 800mg QD, regardless of titration regimen and maintenance dose. SAE incidence was <10%; there were 3 deaths (placebo, n=2; ESL 800mg, n=1). CONCLUSIONS: ESL (800 and 1200mg QD) was effective and well tolerated as adjunctive therapy for adults with refractory POS.


Assuntos
Anticonvulsivantes/administração & dosagem , Ensaios Clínicos Fase III como Assunto/métodos , Dibenzazepinas/administração & dosagem , Epilepsias Parciais/tratamento farmacológico , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Adolescente , Adulto , Relação Dose-Resposta a Droga , Método Duplo-Cego , Quimioterapia Combinada , Epilepsias Parciais/epidemiologia , Feminino , Humanos , Internacionalidade , Masculino , Resultado do Tratamento , Bloqueadores do Canal de Sódio Disparado por Voltagem/administração & dosagem , Adulto Jovem
3.
Exp Parasitol ; 151-152: 34-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25639494

RESUMO

Haemonchus contortus (order Strongylida) is a common parasitic nematode infecting small ruminants and causing significant economic losses worldwide. It induces innate and adaptive immune responses, which are essential for the clearance of this nematode from the host. Ecto-adenosine deaminase (E-ADA) is an enzyme that plays an important role in the immune system, while Zinc (Zn) has been found playing a critical role in E-ADA catalysis. Therefore, the aim of this study was to assess the effect of Zn supplementation on E-ADA activity in serum of lambs experimentally infected with H.contortus. To reach this purpose 28 male lambs (in average 25 kg) were used. The animals were divided into four groups: A and B composed of healthy animals (uninfected); C and D, infected with H.contortus. Groups B and D were supplemented with Zn Edetate, subcutaneously with 3 mg kg of live weight, on days 11 and 25 post-infection (PI). Blood and fecal samples were collected on the days 11, 25 and 39 PI, in order to assess hematocrit, seric E-ADA, and eggs per gram (EPG) counting, respectively. The animals of groups C and D showed severe hematocrit reduction (days 25 and 39 PI) and were EPG positive (days 11, 25 and 39 PI). On day 41 PI, three animals each group were subjected to necropsy. This procedure showed that animals of groups A and B did not have helminths in abomasum and intestines, while H.contortus were observed in groups C (5782.5 ± 810.9) and D (6185.0 ± 150.0). Infected and untreated animals (group C) showed a reduction in E-ADA activity, but this was not observed when the animals were supplemented with Zn (Group D). Therefore, based on our results, it was possible to observe that Zn supplementation exercised a positive effect on E-ADA activity in lambs infected with H.contortus, and did not allow a reduction in E-ADA activity, as occurred in the group infected and without supplementation. However, Zn supplementation was not able to prevent the worm burden.


Assuntos
Adenosina Desaminase/sangue , Hemoncose/veterinária , Doenças dos Ovinos/parasitologia , Zinco/administração & dosagem , Doença Aguda , Anemia/parasitologia , Anemia/veterinária , Animais , Fezes/parasitologia , Hemoncose/tratamento farmacológico , Hemoncose/enzimologia , Hematócrito/veterinária , Intestinos/parasitologia , Masculino , Contagem de Ovos de Parasitas/veterinária , Ovinos , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/enzimologia
4.
Parasitology ; 141(7): 898-903, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24534114

RESUMO

The aim of this study was to evaluate the purine levels of lambs experimentally infected with Haemonchus contortus. A total of 12 healthy lambs were divided into two groups, composed of 6 animals each: Group A represented the healthy animals (uninfected), while in Group B the animals were infected with 15 000 larvae of H. contortus. Blood was drawn on days 15, 45 and 75 post-infection (PI) in order to perform the purine analysis (ATP, ADP, AMP, adenosine, inosine, hypoxanthine, xanthine and uric acid) by high pressure liquid chromatography (HPLC) in serum. On day 15 PI a significant (P<0·05) increase in the levels of ATP and inosine was observed in the infected animals, unlike the levels of ADP, adenosine, xanthine and uric acid which were reduced. On day 45 PI a significant (P<0·05) increase in the ATP and xanthine levels in infected animals was observed, contrasting with reduced levels of ADP and uric acid. Finally, on day 75 PI an increase occurred in the levels of ATP, adenosine and hypoxanthine in infected lambs, concomitant with a reduction in the levels of ADP and uric acid (P<0·05). These changes in purine levels may influence the inflammatory process and the pathological events.


Assuntos
Hemoncose/veterinária , Haemonchus , Purinas/sangue , Doenças dos Ovinos/parasitologia , Animais , Fezes/parasitologia , Hemoncose/sangue , Hemoncose/parasitologia , Masculino , Ovinos , Doenças dos Ovinos/sangue
5.
Br J Clin Pharmacol ; 77(6): 1017-26, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24168152

RESUMO

AIMS: Etamicastat is a reversible dopamine-ß-hydroxylase inhibitor that decreases noradrenaline levels in sympathetically innervated tissues and slows down sympathetic nervous system drive. In this study, the disposition, metabolism and excretion of etamicastat were evaluated following [(14)C]-etamicastat dosing. METHODS: Healthy Caucasian males (n = 4) were enrolled in this single-dose, open-label study. Subjects were administered 600 mg of unlabelled etamicastat and 98 µCi weighing 0.623 mg [(14)C]-etamicastat. Blood samples, urine and faeces were collected to characterize the disposition, excretion and metabolites of etamicastat. RESULTS: Eleven days after administration, 94.0% of the administered radioactivity had been excreted; 33.3 and 58.5% of the administered dose was found in the faeces and urine, respectively. Renal excretion of unchanged etamicastat and its N-acetylated metabolite (BIA 5-961) accounted for 20.0 and 10.7% of the dose, respectively. Etamicastat and BIA 5-961 accounted for most of the circulating radioactivity, with a BIA 5-961/etamicastat ratio that was highly variable both for the maximal plasma concentration (19.68-226.28%) and for the area under the plasma concentration-time curve from time zero to the last sampling time at which the concentration was above the limit of quantification (15.82- 281.71%). Alongside N-acetylation, metabolism of etamicastat also occurs through oxidative deamination of the aminoethyl moiety, alkyl oxidation, desulfation and glucuronidation. CONCLUSIONS: Etamicastat is rapidly absorbed, primarily excreted via urine, and its biotransformation occurs mainly via N-acetylation (N-acetyltransferase type 2), although glucuronidation, oxidation, oxidative deamination and desulfation also take place.


Assuntos
Benzopiranos/metabolismo , Dopamina beta-Hidroxilase/antagonistas & inibidores , Inibidores Enzimáticos/metabolismo , Imidazóis/metabolismo , Adulto , Arilamina N-Acetiltransferase/genética , Radioisótopos de Carbono , Fezes/química , Genótipo , Humanos , Isoenzimas/genética , Masculino , Pessoa de Meia-Idade
6.
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
7.
Rev. bras. cardiol. invasiva ; 19(2): 153-159, jul. 2011. tab
Artigo em Português | LILACS | ID: lil-595228

RESUMO

Introdução: Recentemente a intervenção coronária percutânea (ICP) com stents farmacológicos (SFs) tem se mostrado uma opção viável em pacientes selecionados com lesão de tronco de coronária esquerda não-protegido (TCE-NP). Este estudo teve como objetivo avaliar a efetividade e a segurança da ICP com SFs em lesões de TCE-NP da prática diária, analisando a ocorrência combinada de eventos cardíacos adversos maiores (ECAM) a longo prazo. Métodos: Foram tratados 142 pacientes consecutivos, com média de seguimento clínico de 917 + 743 dias. A decisão de utilizar um ou dois stents e inibidor da glicoproteína IIb/IIIa ficou a critério do operador. Angiografia coronária no seguimento não foi realizada de rotina, mas deixada a critério clínico. Resultados: A média de idade foi de 67,5 + 16 anos, três quartos dos pacientes eram do sexo masculino, 29% eram portadores de diabetes e 39% apresentavam angina instável. Foram utilizados 2,75 + 1,25 stents por paciente. Lesões com comprometimento da bifurcação foram identificadas em 90,1% e as técnicas mais frequentemente utilizadas foram o provisional stent em 36% e o small crush em 29% dos pacientes. Ultrassom intracoronário foi realizado em 92,3% dos pacientes, e reintervenção ocorreu em 21,3% dos stents, por apresentarem aposição incompleta de suas hastes após o implante. ECAM na evolução tardia ocorreram em 15,4%, óbito cardíaco ocorreu em 3,6%, revascularização do vaso-alvo em 11,2% e trombose definitiva / provável do stent em 1,4%. Conclusões: A ICP com SFs em lesões de TCE-NP neste estudo mostrou ser segura e eficazna evolução tardia, com baixas taxas de óbito cardíaco e de trombose do stent.


Background: Recently, percutaneous coronary intervention (PCI) with drug-eluting stents (DES) has proven to be a feasible option in selected patients with unprotected left main (LM) disease. This study was aimed at assessing the efficacy and safety of PCI with DES in LM lesions in the daily practice, analyzing the long-term occurrence of major adverse cardiac events (MACE). Methods: A total of 142 consecutivepatients were treated with a mean follow-up of 917 + 743 days. The decision to use one or two stents or glycoprotein IIb/IIIa inhibitors was left to the operator’s discretion. Coronaryangiography was not performed routinely in the follow-up. Results: Mean age was 67.5 + 16 years, 75% of the patients were male, 29% had diabetes and 39% had unstable angina. A total of 2.75 + 1.25 stents were implanted per patient. Bifurcation lesions were identified in 90.1% and the most frequent techniques were the provisional stent in 36% and small crush in 29% of the patients. Intravascular ultrasound was performed in 92.3% of the patients and reinterventions in 21.3% of the stents due to incomplete appositionof the struts after implantation. In the late follow-up, MACE was observed in 15.4% of the patients, cardiac deathin 3.6%, target-vessel revascularization in 11.2% and definitive/probably stent thrombosis in 1.4%. Conclusions: In thisstudy, PCI with DES proved to be safe and effective in the late follow-up of LM lesions, with low cardiac death and stentthrombosis rates.


Assuntos
Humanos , Masculino , Feminino , Idoso , Angioplastia/métodos , Angioplastia , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/diagnóstico , Infarto do Miocárdio/complicações , Infarto do Miocárdio/mortalidade , Stents Farmacológicos , Aspirina/administração & dosagem , Stents
8.
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
9.
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
10.
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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