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1.
J Clin Lipidol ; 17(1): 181-188, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36529659

RESUMO

BACKGROUND: Pelacarsen is a liver-targeted antisense oligonucleotide that potently lowers lipoprotein(a) [Lp(a)] levels. Its safety and efficacy in diverse populations has not been extensively studied. OBJECTIVE: To assess the effect of pelacarsen, including monthly dosing of 80 mg, in subjects of Japanese ancestry. METHODS: A randomized double-blind, placebo-controlled, study was performed in 29 healthy Japanese subjects treated with single ascending doses (SAD) of pelacarsen 20, 40 and 80 mg subcutaneously or multiple doses (MD) of pelacarsen 80 mg monthly for 4 doses. The primary objective was to assess the safety and tolerability in healthy Japanese subjects; secondary objectives to assess the pharmacokinetics of pelacarsen; and exploratory objective to determine the effect of pelacarsen on plasma Lp(a) levels. RESULTS: No serious adverse events or clinically relevant abnormalities in any laboratory parameters were noted. In the MD cohort, mean plasma concentrations of pelacarsen peaked at ∼4 hours and declined in a bi-exponential manner thereafter. In the SAD cohorts, the placebo-corrected least-square mean (PCLSM) percent changes in Lp(a) at Day 30 were: -55.4% (p=0.0008), -58.9% (p=0.0003) and -73.7% (p<0.0001) for the 20 mg, 40 mg, and 80 mg pelacarsen-treated groups, respectively. In the MD cohort, the PCLSM at Days 29, 85, 113, 176 and 204 were -84.0% (p=0.0003), -106.2% (p<0.0001), -70.0 (p<0.0001), -80.0% (p=0.0104) and -55.8% (p=0.0707), respectively. CONCLUSIONS: Pelacarsen demonstrates an acceptable safety and tolerability profile and potently lowers plasma levels of Lp(a) in healthy Japanese subjects, including with the 80 mg monthly dose being evaluated in the Lp(a) HORIZON trial.


Assuntos
População do Leste Asiático , Lipoproteína(a) , Humanos , Oligonucleotídeos Antissenso , Oligonucleotídeos , Voluntários Saudáveis , Método Duplo-Cego , Relação Dose-Resposta a Droga
2.
Am J Ophthalmol ; 192: 113-123, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29802818

RESUMO

PURPOSE: To assess the clinical safety, tolerability, and efficacy of topically administered MGV354, a soluble guanylate cyclase (sGC) activator, in patients with ocular hypertension (OH) or glaucoma. DESIGN: Double-masked, randomized, and vehicle-controlled study. METHODS: Parts 1 and 2 evaluated safety and tolerability to identify the maximum tolerated dose (MTD) of once-daily MGV354 in 32 healthy volunteers (Part 1) and 16 patients with OH or glaucoma (Part 2) at a single clinical site. Part 3 was a multisite trial that evaluated intraocular pressure (IOP)-lowering efficacy of the MTD administered nightly for 1 week in 50 patients with minimum IOP of 24 mm Hg at 8 AM, with a main outcome measure of mean diurnal IOP at day 8 compared to baseline (ClinicalTrials.govNCT02743780). RESULTS: There was no difference in favor of MGV354 for IOP lowering; change from baseline to day 8 in mean diurnal IOP was -0.6 mm Hg for MGV354-treated patients and -1.1 mm Hg for vehicle-treated patients in Part 3, with a confidence interval of -0.7 to 1.7. The most common adverse events reported after MGV354 administration were conjunctival and ocular hyperemia. CONCLUSIONS: Overall, MGV354 0.1% demonstrated no statistically significant effect compared to vehicle in lowering IOP based on the study's main outcome measure. MGV354 produced ocular hyperemia consistent with its pharmacology.


Assuntos
Ativadores de Enzimas/uso terapêutico , Glaucoma de Ângulo Aberto/tratamento farmacológico , Guanilato Ciclase/metabolismo , Pressão Intraocular/efeitos dos fármacos , Piperidinas/uso terapêutico , Pirazóis/uso terapêutico , Piridinas/uso terapêutico , Administração Oftálmica , Adolescente , Adulto , Idoso , Método Duplo-Cego , Ativadores de Enzimas/efeitos adversos , Feminino , Glaucoma de Ângulo Aberto/fisiopatologia , Humanos , Pressão Intraocular/fisiologia , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Nível de Efeito Adverso não Observado , Hipertensão Ocular/tratamento farmacológico , Hipertensão Ocular/fisiopatologia , Soluções Oftálmicas , Piperidinas/efeitos adversos , Pirazóis/efeitos adversos , Piridinas/efeitos adversos , Tonometria Ocular , Resultado do Tratamento , Acuidade Visual/fisiologia , Adulto Jovem
3.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-696225

RESUMO

Objective To investigate thrombelastogram (TEG) correlation between parameters and platelet count in perioperative period patients.Methods Selected 139 patients,69 cases with thrombocytopenia,35 cases with normal platelet number and 35 cases with thrombocytosis from 2012 January to 2014 May,monitored TEG,blood coagulation function and the change of blood routine during perioperative period.Spearman test was used to analyze the different level of platelet count and other coagulation parameters.Results The positive correlation between platelet count and TEG parameters were:MA (r=0.57,P<0.57),Angle (r=0.54,P<0.000 1),CI (r=0.57,P<0.000 1),and R was negatively correlated with platelet count (r=-0.27,P<0.000 1).There was no significant correlation between PT,APTT and platelet count.In mild lack of platelet group [(87.34 ± 10.43) × 109/L] and normal group [(198.47 ± 45.30) × 109/L],platelet count was positively correlated with MA and Angle.In severe lower [(39.33±10.63) × 109/L] and higher group [(330.34±35.43) × 109/L],there was no correlation between platelet platelet count with MA or Angle.Conclusion Platelet count was significantly correlated with CI,Angle and MA,but in patients with moderately severe lower platelet and platelet increase the platelet count do not reflect the aggregation function,MA is more sensitive response to platelet function.

5.
Birth Defects Res B Dev Reprod Toxicol ; 101(2): 144-51, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24692426

RESUMO

BACKGROUND: Aliskiren is the first orally bioavailable direct renin inhibitor approved for the treatment of hypertension in adults. Juvenile toxicity studies in rats were initiated to support treatment in the pediatric population. METHODS: In Study 1, aliskiren oral administration was initiated on postpartum day (PPD) 14, after nephrogenesis was completed, and continued through PPD 70 at doses of 0, 30, 100, and 300 mg/kg/day. In-life, clinical pathology, anatomic pathology, developmental, behavioral, reproductive, and toxicokinetics evaluations were performed. In Study 2, oral administration was initiated on PPD 8, before completion of nephrogenesis, and continued through PPD 35/36. In-life, clinical pathology, anatomic pathology, developmental, and toxicokinetics evaluations were performed. RESULTS: With dosing initiated on PPD 8, mortality at 100 and 300 mg/kg/day and slightly increased kidney weight at 100 mg/kg/day occurred. Decreased absolute lymphocyte count at 300 mg/kg/day at the end of dosing occurred with dosing initiated on PPD 14. There were clinical signs and transient effects on body weight gains in both studies. There were no changes in other parameters. Systemic exposure was much higher on PPD 8 and 14 compared with adult rats on PPD 64. CONCLUSIONS: All effects produced by aliskiren, including kidney effects, were reversible. Increased exposure in very young animals is considered to be the result of immature drug transporter systems.


Assuntos
Amidas/administração & dosagem , Anti-Hipertensivos/administração & dosagem , Fumaratos/administração & dosagem , Rim/efeitos dos fármacos , Administração Oral , Amidas/efeitos adversos , Animais , Anti-Hipertensivos/efeitos adversos , Comportamento Animal/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Fumaratos/efeitos adversos , Hipertensão/tratamento farmacológico , Contagem de Linfócitos , Masculino , Exposição Materna , Período Pós-Parto/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Reprodução/efeitos dos fármacos , Testes de Toxicidade , Toxicocinética
6.
J Clin Pharmacol ; 54(7): 800-8, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24619917

RESUMO

Pradigastat, a novel diacylglycerol acyltransferase-1 inhibitor, was evaluated for both pharmacokinetic (PK) and pharmacodynamic (PD) drug-drug interactions when co-administered with digoxin or warfarin in healthy subjects. This open-label study included two parallel subject cohorts each with three sequential treatment periods. Forty subjects were enrolled in the study with 20 subjects allocated to each cohort. PK and PD (PT/INR for warfarin only) samples were collected in each period. The statistical analysis results showed that the 90% CIs of the geometric mean ratios of digoxin, R-warfarin, and S-warfarin PK parameters (AUC and Cmax) were all within 0.80-1.25 interval. The 90% CIs of the geometric mean ratios of pradigastat PK parameters (AUC and Cmax) were within 0.80-1.25 interval when co-administered with warfarin; while co-administration with digoxin slightly reduced pradigastat exposure (∼15%). The results also showed that 90% CIs of the geometric mean ratios of warfarin PD parameters (AUC(PT), PTmax, AUC(INR), and INRmax) were within 0.80-1.25 interval. Pradigastat and digoxin or warfarin had no relevant clinical PK or PD drug-drug interactions. Administration of pradigastat and warfarin or pradigastat and digoxin as a mono or combined treatment appears to be safe and tolerated.


Assuntos
Acetatos/farmacocinética , Aminopiridinas/farmacocinética , Cardiotônicos/farmacocinética , Diacilglicerol O-Aciltransferase/antagonistas & inibidores , Digoxina/farmacocinética , Inibidores Enzimáticos/farmacocinética , Hipolipemiantes/farmacocinética , Varfarina/farmacocinética , Acetatos/administração & dosagem , Acetatos/efeitos adversos , Acetatos/sangue , Adolescente , Adulto , Aminopiridinas/administração & dosagem , Aminopiridinas/efeitos adversos , Aminopiridinas/sangue , Cardiotônicos/efeitos adversos , Cardiotônicos/sangue , Estudos de Coortes , Digoxina/efeitos adversos , Digoxina/sangue , Relação Dose-Resposta a Droga , Interações Medicamentosas , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/efeitos adversos , Inibidores Enzimáticos/sangue , Feminino , Meia-Vida , Humanos , Hipolipemiantes/administração & dosagem , Hipolipemiantes/efeitos adversos , Hipolipemiantes/sangue , Coeficiente Internacional Normatizado , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Tempo de Protrombina , Reprodutibilidade dos Testes , Varfarina/efeitos adversos , Varfarina/sangue , Adulto Jovem
7.
Toxicol Appl Pharmacol ; 275(1): 36-43, 2014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-24388840

RESUMO

Juvenile rat toxicity studies with the direct renin inhibitor aliskiren were initiated to support treatment in the pediatric population. In Study 1, aliskiren was administered orally to juvenile rats at doses of 0, 30, 100 or 300 mg/kg/day with repeated dosing from postpartum day (PPD) 8 to PPD 35/36. In-life, clinical pathology, anatomic pathology, and toxicokinetics evaluations were performed. In Study 2, single oral doses of aliskiren (0, 100 or 300 mg/kg) were given to 14-, 21-, 24-, 28-, 31- or 36-day-old rats; in-life data and toxicokinetics were evaluated. Study 3 was a single dose (3 mg/kg i.v.) pharmacokinetic study in juvenile rats on PPD 8, 14, 21 and 28. In Study 4, naïve rats were used to investigate ontogenic changes of the multidrug-resistant protein 1 (MDR1) and the organic anion transporting polypeptide (OATP) mRNA in several organs. Oral administration of aliskiren at 100 and 300 mg/kg caused unexpected mortality and severe morbidity in 8-day-old rats. Aliskiren plasma and tissue concentrations were increased in rats aged 21days and younger. Expression of MDR1 and OATP mRNA in the intestine, liver and brain was significantly lower in very young rats. In conclusion, severe toxicity and increased exposure in very young rats after oral administration of aliskiren are considered to be the result of immature drug transporter systems. Immaturity of MDR1 in enterocytes appears to be the most important mechanism responsible for the high exposure.


Assuntos
Envelhecimento , Amidas/efeitos adversos , Anti-Hipertensivos/efeitos adversos , Fumaratos/efeitos adversos , Renina/antagonistas & inibidores , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Administração Oral , Amidas/administração & dosagem , Amidas/metabolismo , Amidas/farmacocinética , Animais , Anti-Hipertensivos/administração & dosagem , Anti-Hipertensivos/metabolismo , Anti-Hipertensivos/farmacocinética , Relação Dose-Resposta a Droga , Regulação para Baixo/efeitos dos fármacos , Feminino , Fumaratos/administração & dosagem , Fumaratos/metabolismo , Fumaratos/farmacocinética , Injeções Intravenosas , Jejuno/efeitos dos fármacos , Jejuno/crescimento & desenvolvimento , Jejuno/metabolismo , Fígado/efeitos dos fármacos , Fígado/crescimento & desenvolvimento , Fígado/metabolismo , Masculino , Transportadores de Ânions Orgânicos/antagonistas & inibidores , Transportadores de Ânions Orgânicos/genética , Transportadores de Ânions Orgânicos/metabolismo , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Distribuição Tecidual , Testes de Toxicidade
8.
Int J Clin Pharmacol Ther ; 51(12): 948-57, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24120715

RESUMO

BACKGROUND: QT interval prolongation is associated with an increased risk of potentially fatal ventricular tachycardias, including torsade de pointes. Regulatory guidance recommends the "thorough QT/QTc" (TQT) study as the gold standard for assessing the propensity of novel nonantiarrhythmic drugs to delay cardiac repolarization. An opportunity exists, however, to use high-quality electrocardiogram (ECG) data from first-in-man trials as an exploratory and complementary approach to gain early insight into potential risk of QT prolongation. METHODS: We collected high-quality, triplicate, 12-lead ECG data during a first-in-man trial of a drug developed for the treatment of Type 2 diabetes that had shown in vitro hERG inhibition and potential to prolong QT intervals in an animal model. RESULTS: QTc prolongation was observed at the highest dose, leading to a maximum QTcF prolongation > 19 ms at 6 hours after the 14th daily dose. QTcF increases from time-matched baseline relative to placebo were positively correlated with peak plasma concentrations. CONCLUSIONS: Clinically relevant QT interval prolongations can be detected during first-in-man studies using high-quality ECG monitoring. Such data may facilitate early decision making on whether to terminate the development of a compound and invest resources in more promising molecules; and it may enable more efficient TQT study design or preclude the need for future TQT studies.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Eletrocardiografia/efeitos dos fármacos , Canais de Potássio Éter-A-Go-Go/antagonistas & inibidores , Hipoglicemiantes/efeitos adversos , Receptores Acoplados a Proteínas G/agonistas , Adulto , Método Duplo-Cego , Canal de Potássio ERG1 , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
9.
Clin Pediatr (Phila) ; 52(7): 599-607, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23610239

RESUMO

OBJECTIVE: To assess the pharmacokinetics (PK) and safety profile of aliskiren in pediatric patients (6-17 years old) with hypertension. METHODS: Patients were randomized to a single weight-based dose of either 2 mg/kg (n = 19) or 6 mg/kg (n = 20) of aliskiren daily for 8 days. The PK, pharmacodynamics, safety profile, and efficacy of aliskiren were assessed. RESULTS: Of the 39 randomized patients, 37 (94.9%) completed the study. Aliskiren plasma concentration (maximum plasma concentration and area under the plasma concentration-time curve) increased dose dependently, achieving peak concentrations in 1 to 2 hours, and t(max) was comparable across the dose and age groups. Treatment-emergent adverse events (AEs) were reported in 18 (46.2%) patients, with headache, abdominal pain, and nausea being the most frequent. CONCLUSIONS: Aliskiren 2 mg/kg and 6 mg/kg daily showed dose-dependent increases in the plasma concentration. The drug was well tolerated in hypertensive children aged 6 to 17 years. AEs were generally mild and not related to either the drug or the dose.


Assuntos
Amidas/farmacocinética , Amidas/uso terapêutico , Anti-Hipertensivos/farmacocinética , Anti-Hipertensivos/uso terapêutico , Fumaratos/farmacocinética , Fumaratos/uso terapêutico , Hipertensão/tratamento farmacológico , Administração Oral , Adolescente , Fatores Etários , Amidas/efeitos adversos , Amidas/sangue , Análise de Variância , Anti-Hipertensivos/efeitos adversos , Criança , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Fumaratos/efeitos adversos , Fumaratos/sangue , Humanos , Masculino , Análise de Regressão , Comprimidos , Resultado do Tratamento
10.
J Clin Pharmacol ; 52(5): 645-55, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-21659626

RESUMO

Single-pill combinations (SPCs) of complementary antihypertensive agents provide patients with a simple and effective treatment regimen. To ensure that the efficacy and safety of an SPC is the same as that for the individual drugs administered together (free combination), SPC and free-combination formulations must be shown to be bioequivalent. Three open-label, randomized studies compared the pharmacokinetics of SPC tablets of the direct renin inhibitor aliskiren and hydrochlorothiazide (HCT), at doses of 150/25, 300/12.5, and 300/25 mg, with the corresponding free combinations in healthy volunteers. Data from 2 randomized, double-blinded studies of patients with hypertension were used to assess inhibition of plasma renin activity (PRA) by the aliskiren/HCT 300/25 mg SPC and the free combination. At all dose combinations, aliskiren and HCT systemic drug exposure was similar when administered as an SPC or free combination, indicating bioequivalence. Aliskiren/HCT 300/25 mg SPC inhibited PRA to the same extent as the free combination. HCT alone increased PRA through activation of the renin-angiotensin system; aliskiren prevented this diuretic-induced increase to the same extent when administered as the free combination or as the SPC. In conclusion, aliskiren/HCT SPCs are pharmacokinetically and pharmacodynamically bioequivalent to aliskiren and HCT in free combination.


Assuntos
Amidas/farmacocinética , Anti-Hipertensivos/farmacocinética , Pressão Sanguínea/efeitos dos fármacos , Diuréticos/farmacocinética , Fumaratos/farmacocinética , Hidroclorotiazida/farmacocinética , Hipertensão/tratamento farmacológico , Administração Oral , Adolescente , Adulto , Amidas/administração & dosagem , Amidas/efeitos adversos , Análise de Variância , Anti-Hipertensivos/administração & dosagem , Anti-Hipertensivos/efeitos adversos , Estudos Cross-Over , Diuréticos/administração & dosagem , Diuréticos/efeitos adversos , Método Duplo-Cego , Combinação de Medicamentos , Quimioterapia Combinada , Feminino , Fumaratos/administração & dosagem , Fumaratos/efeitos adversos , Humanos , Hidroclorotiazida/administração & dosagem , Hidroclorotiazida/efeitos adversos , Hipertensão/sangue , Hipertensão/fisiopatologia , Análise dos Mínimos Quadrados , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Renina/antagonistas & inibidores , Renina/metabolismo , Comprimidos , Equivalência Terapêutica , Resultado do Tratamento , Adulto Jovem
11.
J Clin Pharmacol ; 47(10): 1327-34, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17675455

RESUMO

This study evaluated the effect of entecavir on the pharmacokinetics of adefovir and the effect of adefovir on the pharmacokinetics of entecavir using a fixed-sequence crossover design in healthy adult subjects. Subjects received 10 mg of adefovir once daily on days 1 to 4, 1 mg of entecavir on days 5 to 14, and 1 mg of entecavir plus 10 mg of adefovir on days 15 to 24. Pharmacokinetic assessments were performed on days 4 and 24 for adefovir and on days 14 and 24 for entecavir. The geometric mean ratios (90% confidence interval) for area under the plasma concentration-time curve in 1 dosing interval, peak plasma concentration, and 24-hour postdose plasma concentration of entecavir when coadministered with adefovir and of adefovir when coadministered with entecavir were within the prespecified 0.80 to 1.25 no-effect range. Entecavir and adefovir were well tolerated when administered in combination. Therefore, the pharmacokinetic data generated in this study indicate that entecavir and adefovir can be coadministered without the need for dosage adjustment.


Assuntos
Adenina/análogos & derivados , Antivirais/farmacocinética , Guanina/análogos & derivados , Organofosfonatos/farmacocinética , Adenina/administração & dosagem , Adenina/efeitos adversos , Adenina/farmacocinética , Adolescente , Adulto , Antivirais/administração & dosagem , Antivirais/efeitos adversos , Área Sob a Curva , Estudos Cross-Over , Interações Medicamentosas , Feminino , Guanina/administração & dosagem , Guanina/efeitos adversos , Guanina/farmacocinética , Humanos , Masculino , Organofosfonatos/administração & dosagem , Organofosfonatos/efeitos adversos
12.
J Sep Sci ; 30(9): 1267-75, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17623467

RESUMO

BMS-378806 is a human immunodeficiency virus (HIV) entry inhibitor that is being developed for the oral treatment of HIV infection. Human plasma and urine LC/MS/ MS methods have been developed and validated for the quantitation of BMS-378806. For human plasma method, methyl t-butyl ether was used to extract BMS-378806 from plasma in a 96-well format, and the organic layers were dried down and then reconstituted for the injection, while a dilute-and-shoot approach was used for human urine method in a 96-well format. Chromatographic separation was achieved isocratically on a Phenomenex C18 (2) Luna column (2 x 50 mm2, 5 microm). The mobile phase contained 60:40 v/v of 0.1% formic acid in water and ACN. Detection was by positive ion electrospray MS/MS. The standard curves ranged from 1.25 to 1000 ng/mL for the plasma assay and from 10 to 5000 ng/mL for the urine assay. The curves were fitted to a 1/x2 weighted quadratic regression model for both methods. The validation results demonstrated that both methods had satisfactory precision and accuracy across the calibration ranges. The methods were applied to the analysis of human plasma and urine samples from a single ascending dose clinical study to assess the pharmacokinetics of the drug. The pharmacokinetic analysis results indicated the absorption and disposition of the drug was rapid. The systemic exposure of BMS-378806 was generally dose proportional among the doses from 100 to 1200 mg, but not dose proportional to 1600 mg. There were modest increases in the systemic exposure when the drug was given with food or given as a solution formulation. Renal excretion was not a substantial elimination pathway of the drug. BMS378806 was safe and well tolerated over a dose range of 100-1600 mg administered as a single oral dose.


Assuntos
Inibidores da Fusão de HIV/sangue , Inibidores da Fusão de HIV/urina , Piperazinas/sangue , Piperazinas/urina , Cromatografia Líquida de Alta Pressão/métodos , Inibidores da Fusão de HIV/farmacocinética , Humanos , Piperazinas/farmacocinética , Espectrometria de Massas em Tandem/métodos
13.
J Clin Pharmacol ; 46(11): 1250-8, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17050790

RESUMO

A double-blind, placebo-controlled, multiple oral dose escalation study was conducted to investigate the pharmacokinetics, safety, and tolerability of entecavir in healthy subjects. Eight subjects were assigned to each of the 3 dose panels (0.1 mg, 0.5 mg, and 1 mg or matched placebo once daily for 14 days). Blood and urine samples were collected for pharmacokinetic analyses. Entecavir was rapidly absorbed, with peak plasma concentration occurring within 1 hour of dosing. Steady-state plasma concentrations of entecavir were achieved by 10 days following the initial dose. At steady state, the mean area under the plasma concentration-time curve over 1 dosing interval, increased approximately proportional to dose. Entecavir had a mean terminal half-life ranging from 128 to 149 hours and an effective half-life of approximately 24 hours. Elimination was predominantly through renal excretion, with mean urinary recovery ranging from 62% to 73%. Entecavir was safe and well tolerated when administered at doses ranging from 0.1 mg to 1 mg/d for 14 days.


Assuntos
Antivirais/efeitos adversos , Antivirais/farmacocinética , Guanina/análogos & derivados , Adulto , Antivirais/administração & dosagem , Antivirais/sangue , Relação Dose-Resposta a Droga , Guanina/administração & dosagem , Guanina/efeitos adversos , Guanina/sangue , Guanina/farmacocinética , Humanos , Masculino , Pessoa de Meia-Idade
14.
J Clin Pharmacol ; 46(2): 193-200, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16432271

RESUMO

An open-label, nonrandomized study was conducted to assess the effect of ravuconazole on the pharmacokinetics of concomitantly administered nelfinavir. Healthy volunteers received 750 mg nelfinavir on day 1, 750 mg nelfinavir and 400 mg ravuconazole on day 2, 400 mg ravuconazole on days 3 to 28, and 750 mg nelfinavir and 400 mg ravuconazole on day 29. The geometric means of C(max) and area under the curve of nelfinavir coadministered with ravuconazole were 30.7% and 31.9% higher on day 2 and 7.9% and 16.2% lower on day 29, respectively, compared to the corresponding values on day 1. These findings are consistent with the potential for ravuconazole to both inhibit and induce CYP3A isozymes. The alterations in the systemic exposure to nelfinavir were within the range defined by the 90% confidence interval. The study data indicate that coadministration of ravuconazole did not result in a clinically significant change in the plasma levels of nelfinavir.


Assuntos
Fármacos Anti-HIV/farmacocinética , Nelfinavir/farmacocinética , Tiazóis/farmacologia , Triazóis/farmacologia , Adolescente , Adulto , Fármacos Anti-HIV/efeitos adversos , Área Sob a Curva , Citocromo P-450 CYP3A/metabolismo , Interações Medicamentosas , Meia-Vida , Humanos , Masculino , Pessoa de Meia-Idade , Nelfinavir/efeitos adversos , Tiazóis/efeitos adversos , Triazóis/efeitos adversos
15.
J Clin Pharmacol ; 45(4): 434-45, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15778424

RESUMO

This was an open-label, nonrandomized, 2-center study conducted to assess the influence of renal function on the pharmacokinetics of hydroxyurea in adults with sickle cell disease (SCD). Seventeen patients were divided into 5 groups: normal renal function (n = 7), mild renal impairment (n = 2), moderate renal impairment (n = 3), severe renal impairment (n = 2), and end-stage renal disease (ESRD, n = 3). Except for patients with ESRD, all the patients received a 15-mg/kg single oral dose of hydroxyurea. Patients with ESRD received a 15-mg/kg oral dose of hydroxyurea on 2 occasions. Blood and urine samples were collected for the assessment of hydroxyurea pharmacokinetics. The results indicate that the systemic exposure increases and the urinary recovery decreases as the degree of renal insufficiency worsens. On the basis of the exposure and the apparent clearance from the current and 2 historical studies, the authors have proposed an initial dosing regimen of hydroxyurea (7.5 mg/kg/day) for SCD patients with CL(cr) <60 mL/min. This dosing strategy is anticipated to provide a safe dose for SCD patients with renal impairment.


Assuntos
Anemia Falciforme/sangue , Hidroxiureia/farmacocinética , Falência Renal Crônica/sangue , Rim/metabolismo , Adulto , Idoso , Anemia Falciforme/tratamento farmacológico , Feminino , Humanos , Hidroxiureia/administração & dosagem , Rim/efeitos dos fármacos , Falência Renal Crônica/tratamento farmacológico , Testes de Função Renal , Masculino , Pessoa de Meia-Idade
16.
J Clin Pharmacol ; 42(4): 419-27, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11936567

RESUMO

The objective of this study was to assess the effect of food and timing of meals on the bioavailability of didanosine from encapsulated enteric-coated beads. Four different independent, open-label, single-dose, randomized, crossover studies were conducted in healthy subjects (n = 20-30). Didanosine (400 mg) was given concomitantly with a high-fat meal, light meal, yogurt, and applesauce. In addition, didanosine was given 1, 1.5, 2, and 3 hours before and 2 hours after a light meal. Statistical comparison with fasting conditions was made using the equivalence approach for Cmax (70%-143%) and AUC (80%-125%). The high-fat meal, light meal, yogurt, and applesauce decreased the Cmax by 46%, 22%, 30%, and 24%, respectively, and lowered the AUC by 19%, 27%, 20%, and 18%, respectively; statistical analyses indicated an indeterminate food effect, except for the Cmax for the high-fat meal. For 1 hour before meal, Cmax and AUC were lower by 15% and 24% and, for 2 hours after meal, were lower by 15% and 10%, respectively. There was an indeterminate food effect for 1 hour before the meal treatment; in addition, 2 hours after the meal, treatment approached statistical equivalence, missing narrowly on the lower bounds. For 1.5, 2, and 3 hours before meal treatments, Cmax values were unchanged, but AUC was lower by 10%, 4%, and 0%, respectively; lack of food effect was observed for all three treatments. Across studies, median time to Cmix ranged from 1.67 to 2.67 hours but was delayed by 2.5 to 3 hours with high-fat and light meals compared to fasting conditions. The half-life of didanosine was 1.5 to 2 hours. It was concluded that the bioavailability of didanosine from encapsulated enteric-coated beads was reduced by approximately 20% to 25% with food, which can be circumvented by taking didanosine on an empty stomach. The clinical significance of such moderate reductions in didanosine exposure with food, especially as part of a highly active antiretroviral therapy, is not clear.


Assuntos
Didanosina/sangue , Interações Alimento-Droga/fisiologia , Administração Oral , Adulto , Fármacos Anti-HIV/administração & dosagem , Fármacos Anti-HIV/efeitos adversos , Fármacos Anti-HIV/sangue , Área Sob a Curva , Disponibilidade Biológica , Intervalos de Confiança , Estudos Cross-Over , Didanosina/administração & dosagem , Didanosina/efeitos adversos , Gorduras na Dieta/sangue , Jejum/sangue , Feminino , Humanos , Masculino , Microesferas , Comprimidos com Revestimento Entérico
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