RESUMO
BACKGROUND: Virological failure during antiretroviral treatment (ART) may indicate the presence of drug resistance, but may also originate from nonadherence. Qualitative detection of ART components using drug level testing may be used to differentiate between these scenarios. We aimed to validate and implement qualitative point-of-care drug level tests for efavirenz (EFV), lopinavir (LPV), and dolutegravir (DTG) in rural South Africa. METHODS: Qualitative performance of immunoassays for EFV, LPV, and DTG was assessed by calculating limit of detection (LoD), region of uncertainty, and qualitative agreement with a reference test. Minimum duration of nonadherence resulting in a negative drug level test was assessed by simulation of treatment cessation using validated population pharmacokinetic models. RESULTS: LoD was 0.05 mg/L for EFV, 0.06 mg/L for LPV, and 0.02 mg/L for DTG. Region of uncertainty was 0.01-0.06 mg/L for EFV, 0.01-0.07 mg/L for LPV, and 0.01-0.02 mg/L for DTG. Qualitative agreement with reference testing at the LoD in patient samples was 95.2% (79/83) for EFV, 99.3% (140/141) for LPV, and 100% (118/118) for DTG. After simulated treatment cessation, median time to undetectability below LoD was 7 days [interquartile range (IQR) 4-13] for EFV, 30 hours (IQR 24-36) for LPV, and 6 days (IQR 4-7) for DTG. CONCLUSIONS: We demonstrate that qualitative ART drug level testing using immunoassays is feasible in a rural resource-limited setting. Implementation of this technology enables reliable detection of recent nonadherence and may allow for rapid and cost-effective differentiation between patients in need for adherence counseling and patients who require drug resistance testing or alternative treatment.
Assuntos
Alcinos/administração & dosagem , Fármacos Anti-HIV/sangue , Benzoxazinas/administração & dosagem , Ciclopropanos/administração & dosagem , Compostos Heterocíclicos com 3 Anéis/administração & dosagem , Lopinavir/administração & dosagem , Adesão à Medicação , Oxazinas/administração & dosagem , Piperazinas/administração & dosagem , Testes Imediatos/normas , Piridonas/administração & dosagem , Alcinos/farmacocinética , Alcinos/uso terapêutico , Fármacos Anti-HIV/administração & dosagem , Benzoxazinas/farmacocinética , Benzoxazinas/uso terapêutico , Ciclopropanos/farmacocinética , Ciclopropanos/uso terapêutico , Infecções por HIV/tratamento farmacológico , Infecções por HIV/metabolismo , HIV-1 , Compostos Heterocíclicos com 3 Anéis/farmacocinética , Compostos Heterocíclicos com 3 Anéis/uso terapêutico , Humanos , Técnicas Imunoenzimáticas/métodos , Limite de Detecção , Lopinavir/farmacocinética , Lopinavir/uso terapêutico , Oxazinas/farmacocinética , Oxazinas/uso terapêutico , Piperazinas/farmacocinética , Piperazinas/uso terapêutico , Testes Imediatos/economia , Piridonas/farmacocinética , Piridonas/uso terapêutico , Reprodutibilidade dos Testes , População Rural , África do SulRESUMO
Antiretroviral therapy during pregnancy reduces the risk of vertical HIV-1 transmission. However, drug dosing is challenging as pharmacokinetics (PK) may be altered during pregnancy. We combined a pregnancy physiologically-based pharmacokinetic (PBPK) modeling approach with data on placental drug transfer to simulate maternal and fetal exposure to dolutegravir (DTG). First, a PBPK model for DTG exposure in healthy volunteers was established based on physiological and DTG PK data. Next, the model was extended with a fetoplacental unit using transplacental kinetics obtained by performing ex vivo dual-side human cotyledon perfusion experiments. Simulations of fetal exposure after maternal dosing in the third trimester were in accordance with clinically observed DTG cord blood data. Furthermore, the predicted fetal trough plasma concentration (Ctrough ) following 50 mg q.d. dosing remained above the concentration that results in 90% of viral inhibition. Our integrated approach enables simulation of maternal and fetal DTG exposure, illustrating this to be a promising way to assess DTG PK during pregnancy.
Assuntos
Inibidores de Integrase de HIV/farmacocinética , Compostos Heterocíclicos com 3 Anéis/farmacocinética , Modelos Biológicos , Oxazinas/farmacocinética , Piperazinas/farmacocinética , Placenta/metabolismo , Piridonas/farmacocinética , Relação Dose-Resposta a Droga , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/prevenção & controle , Inibidores de Integrase de HIV/administração & dosagem , Compostos Heterocíclicos com 3 Anéis/administração & dosagem , Humanos , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Troca Materno-Fetal , Oxazinas/administração & dosagem , Piperazinas/administração & dosagem , Gravidez , Terceiro Trimestre da Gravidez , Piridonas/administração & dosagemRESUMO
This single-dose study evaluated the bioequivalence, food effect, and safety of 2 experimental, 2-drug, fixed-dose formulations of 50 mg dolutegravir and 300 mg lamivudine (formulation AH and formulation AK) as compared with coadministration of single-entity tablets of 50 mg dolutegravir and 300 mg lamivudine (reference). In fasted subjects, formulation AH lamivudine exposure was similar to the reference; however, dolutegravir exposure was consistently higher in formulation AH, with area under the concentration-time curve (AUC) and maximum concentration (Cmax ) approximately 27% to 28% greater than reference. Formulation AK met bioequivalence standards to the reference for dolutegravir (AUC0-∞ and Cmax ) and lamivudine (AUC0-∞ and AUC0-t ) exposure; however, dolutegravir AUC0-t and lamivudine Cmax were approximately 16% and 32% higher than the reference, respectively. A high-fat meal increased dolutegravir AUC and Cmax by up to 33% and 21%, respectively, and decreased lamivudine Cmax by approximately 30%. Both test and reference formulations were well tolerated. The results support further development of formulation AK as a novel, 2-drug, fixed-dose combination tablet treatment for patients with HIV.
Assuntos
Jejum/metabolismo , Alimentos/efeitos adversos , Infecções por HIV/tratamento farmacológico , Compostos Heterocíclicos com 3 Anéis/farmacocinética , Lamivudina/farmacocinética , Oxazinas/farmacocinética , Piperazinas/farmacocinética , Piridonas/farmacocinética , Administração Oral , Adulto , Área Sob a Curva , Índice de Massa Corporal , Quimioterapia Combinada , Feminino , Infecções por HIV/metabolismo , Inibidores de Integrase de HIV/administração & dosagem , Inibidores de Integrase de HIV/efeitos adversos , Inibidores de Integrase de HIV/farmacocinética , HIV-1/efeitos dos fármacos , HIV-1/isolamento & purificação , Compostos Heterocíclicos com 3 Anéis/administração & dosagem , Compostos Heterocíclicos com 3 Anéis/efeitos adversos , Humanos , Lamivudina/administração & dosagem , Lamivudina/efeitos adversos , Masculino , Pessoa de Meia-Idade , Oxazinas/administração & dosagem , Oxazinas/efeitos adversos , Piperazinas/administração & dosagem , Piperazinas/efeitos adversos , Piridonas/administração & dosagem , Piridonas/efeitos adversos , Inibidores da Transcriptase Reversa/administração & dosagem , Inibidores da Transcriptase Reversa/efeitos adversos , Inibidores da Transcriptase Reversa/farmacocinética , Segurança , Equivalência TerapêuticaRESUMO
Green tea extracts (GTE) has been reported to be a kinase inhibitor and modulator for various drug metabolizing enzymes. It may give synergetic antioncogenic effect, but with a possibility of pharmacokinetic interactions with various co-administered anticancer agents like palbociclib (PAL), a selective inhibitor of CDK-4/6 primarily metabolized by CYP3A enzyme. To explore the impact of GTE on PAL pharmacokinetics in Sprague-Dawley rats, a rapid and sensitive UHPLC-QTOF-MS method was established. Chromatographic separation was carried out on an Acquity UPLC BEH C18 (100 × 2.1 mm, 1.7 µm) column using a gradient mobile phase system consisting of 0.1% formic acid and acetonitrile. Sample preparation was based on a simple protein precipitation method. Estimation of target ions [M + H]+ at m/z 448.2455 for PAL and m/z 441.2044 for ibrutinib (IS) was performed in selective ion mode ESI-HRMS. Good sensitivity (1.0 ng/mL) and linearity over a wide concentration range of 1-2000 ng/mL was exhibited by the method. The results indicated that the administration of GTE resulted in decreased oral bioavailability of PAL in both short- and long-term conditions. However, when both conditions were compared, the variation was less for the peak concentration and area under the concentration-time curve level of PAL.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Interações Ervas-Drogas , Piperazinas , Extratos Vegetais/farmacologia , Piridinas , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Chá/química , Animais , Estabilidade de Medicamentos , Limite de Detecção , Modelos Lineares , Masculino , Piperazinas/sangue , Piperazinas/química , Piperazinas/farmacocinética , Piridinas/sangue , Piridinas/química , Piridinas/farmacocinética , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos TestesRESUMO
BACKGROUND: Artemisinin resistance observed in Southeast Asia threatens the continued use of artemisinin-based combination therapy in endemic countries. Additionally, the diversity of chemical mode of action in the global portfolio of marketed antimalarials is extremely limited. Addressing the urgent need for the development of new antimalarials, a chemical class of potent antimalarial compounds with a novel mode of action was recently identified. Herein, the preclinical characterization of one of these compounds, ACT-451840, conducted in partnership with academic and industrial groups is presented. METHOD AND FINDINGS: The properties of ACT-451840 are described, including its spectrum of activities against multiple life cycle stages of the human malaria parasite Plasmodium falciparum (asexual and sexual) and Plasmodium vivax (asexual) as well as oral in vivo efficacies in two murine malaria models that permit infection with the human and the rodent parasites P. falciparum and Plasmodium berghei, respectively. In vitro, ACT-451840 showed a 50% inhibition concentration of 0.4 nM (standard deviation [SD]: ± 0.0 nM) against the drug-sensitive P. falciparum NF54 strain. The 90% effective doses in the in vivo efficacy models were 3.7 mg/kg against P. falciparum (95% confidence interval: 3.3-4.9 mg/kg) and 13 mg/kg against P. berghei (95% confidence interval: 11-16 mg/kg). ACT-451840 potently prevented male gamete formation from the gametocyte stage with a 50% inhibition concentration of 5.89 nM (SD: ± 1.80 nM) and dose-dependently blocked oocyst development in the mosquito with a 50% inhibitory concentration of 30 nM (range: 23-39). The compound's preclinical safety profile is presented and is in line with the published results of the first-in-man study in healthy male participants, in whom ACT-451840 was well tolerated. Pharmacokinetic/pharmacodynamic (PK/PD) modeling was applied using efficacy in the murine models (defined either as antimalarial activity or as survival) in relation to area under the concentration versus time curve (AUC), maximum observed plasma concentration (Cmax), and time above a threshold concentration. The determination of the dose-efficacy relationship of ACT-451840 under curative conditions in rodent malaria models allowed prediction of the human efficacious exposure. CONCLUSION: The dual activity of ACT-451840 against asexual and sexual stages of P. falciparum and the activity on P. vivax have the potential to meet the specific profile of a target compound that could replace the fast-acting artemisinin component and harbor additional gametocytocidal activity and, thereby, transmission-blocking properties. The fast parasite reduction ratio (PRR) and gametocytocidal effect of ACT-451840 were recently also confirmed in a clinical proof-of-concept (POC) study.
Assuntos
Acrilamidas/farmacologia , Antimaláricos/farmacologia , Piperazinas/farmacologia , Plasmodium falciparum/efeitos dos fármacos , Plasmodium vivax/efeitos dos fármacos , Acrilamidas/farmacocinética , Animais , Antimaláricos/farmacocinética , Artemisininas/farmacologia , Relação Dose-Resposta a Droga , Feminino , Humanos , Camundongos , Camundongos Endogâmicos NOD , Testes de Sensibilidade Microbiana , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Piperazinas/farmacocinética , Plasmodium berghei/efeitos dos fármacosRESUMO
We have developed (18) F-trans-Mefway ((18) F-Mefway) for positron emission tomography (PET) imaging studies of serotonin 5-HT1A receptors which are implicated in various brain functions. Translation of imaging the 5-HT1A receptor in animal models to humans will facilitate an understanding of the role of the receptor in human brain disorders. We report comparative brain distribution of (18) F-Mefway in normal mice, rats, monkeys, and healthy human volunteers. Mefway was found to be very selective, with subnanomolar affinity for the 5-HT1A receptor. Affinities of >55 nM were found for all other human-cloned receptor subtypes tested. Mefway was found to be a poor substrate (>30 µM) for the multidrug resistance 1 protein, suggesting low likelihood of brain uptake being affected by P-glycoprotein. Cerebellum was used as a reference region in all imaging studies across all species due to the low levels of (18) F-Mefway binding. Consistent binding of (18) F-Mefway in cortical regions, hippocampus, and raphe was observed across all species. (18) F-Mefway in the human brain regions correlated with the known postmortem distribution of 5-HT1A receptors. Quantitation of raphe was affected by the resolution of the PET scanners in rodents, whereas monkeys and humans showed a raphe to cerebellum ratio of approximately 3. (18) F-Mefway appears to be an effective 5-HT1A receptor imaging agent in all models, including humans. (18) F-Mefway therefore may be used to quantify 5-HT1A receptor distribution in brain regions for the study of various CNS disorders. J. Comp. Neurol. 524:1457-1471, 2016. © 2015 Wiley Periodicals, Inc.
Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Piperazinas/farmacocinética , Piridinas/farmacocinética , Receptor 5-HT1A de Serotonina/metabolismo , 8-Hidroxi-2-(di-n-propilamino)tetralina/farmacologia , Antagonistas de Receptores Adrenérgicos alfa 1/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Mapeamento Encefálico , Relação Dose-Resposta a Droga , Feminino , Análise de Fourier , Humanos , Processamento de Imagem Assistida por Computador , Macaca mulatta , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Tomografia por Emissão de Pósitrons , Prazosina/farmacologia , Ligação Proteica/efeitos dos fármacos , Compostos Radiofarmacêuticos/farmacocinética , Ratos , Ratos Sprague-Dawley , Agonistas do Receptor de Serotonina/farmacologiaRESUMO
AZD2327 is a brain-penetrant agonist at δ opioid receptors which has antidepressant and anxiolytic properties in a wide array of animal models. As part of the preclinical safety pharmacology assessment, a number of studies were conducted in order to characterize its behavioral effects and its potential for abuse, in order to enable testing in humans. AZD2327 produced only modest effects when tested in a multiple fixed-ratio differential reinforcement of low rate schedule in rats, and did not enhance the rate-suppressing effects of ethanol in the procedure. In a suppressed responding test, AZD2327 only reduced rates of unpunished responding. In drug discrimination studies, AZD2327 produced partial or no generalization from known drugs of abuse. In primates trained to self-administer cocaine, substitution with AZD2327 did not result in appreciable self-administration of AZD2327, indicating that it does not behave as a positive reinforcer under the present conditions. Following termination of repeated administration of AZD2327, no signs of physical dependence (withdrawal) were noted. Overall, the data suggest that AZD2327 does not possess a high potential for abuse, and appears to have only subtle behavioral effects as measured by operant behaviors.
Assuntos
Benzamidas/farmacologia , Condicionamento Operante/efeitos dos fármacos , Piperazinas/farmacologia , Receptores Opioides delta/agonistas , Animais , Benzamidas/administração & dosagem , Benzamidas/farmacocinética , Feminino , Humanos , Macaca mulatta , Masculino , Piperazinas/administração & dosagem , Piperazinas/farmacocinética , Ratos , Ratos Long-Evans , Saimiri , AutoadministraçãoRESUMO
A rapid, sensitive and selective high performance liquid chromatography-electrospray ionization-tandem mass spectrometry method (HPLC-ESI-MS/MS) was developed and validated for the determination and pharmacokinetic investigation of lomerizine in human plasma. Protein precipitation process was used to extract lomerizine from human plasma. Plasma samples were separated by HPLC on an Agela Venusil XBP Phenyl column (100 mm × 2.1 mm, 5 µm) using a mobile phase consisting of methanol-2mM ammonium acetate-formic acid (70:30:0.1, v/v/v) and the flow rate was set at 0.35 mL/min. The total run time was 4.0 min and the elution of lomerizine was at 1.9 min. The detection was performed on a triple quadrupole tandem mass spectrometer in the multiple reaction-monitoring (MRM) mode using the respective [M+H](+) ions m/z 469.2â181.0 for lomerizine and m/z 405.2â202.9 for the I.S. The calibration curve was linear over the range of 0.1-25 ng/mL (r(2)>0.99) with a limit of quantitation (LOQ) of 0.1 ng/mL. The intra- and inter-day precision (relative standard deviation, RSD) values were below 9.65% and the mean accuracy was from 99.00 to 103.00% at four quality control levels. Lomerizine was stable during stability studies, i.e., long term, auto-sampler and freeze/thaw cycles. The method was successfully applied for the evaluation of pharmacokinetics of lomerizine after single oral doses of 10 mg lomerizine to 18 healthy volunteers.
Assuntos
Bloqueadores dos Canais de Cálcio/sangue , Cromatografia Líquida de Alta Pressão/métodos , Piperazinas/sangue , Espectrometria de Massas em Tandem/métodos , Adulto , Bloqueadores dos Canais de Cálcio/farmacocinética , Humanos , Masculino , Piperazinas/farmacocinética , Espectrometria de Massas por Ionização por Electrospray/métodos , Adulto JovemAssuntos
Antineoplásicos , Benzamidas , Indústria Farmacêutica/legislação & jurisprudência , Patentes como Assunto , Piperazinas , Pirimidinas , Antineoplásicos/química , Antineoplásicos/farmacocinética , Benzamidas/química , Benzamidas/farmacocinética , Cristalização , Medicamentos Genéricos , Mesilato de Imatinib , Índia , Piperazinas/química , Piperazinas/farmacocinética , Pirimidinas/química , Pirimidinas/farmacocinéticaRESUMO
This paper investigates a new hierarchical method to apply basis function to mono- and multi-compartmental models (Hierarchical-Basis Function Method, H-BFM) at a voxel level. This method identifies the parameters of the compartmental model in its nonlinearized version, integrating information derived at the region of interest (ROI) level by segmenting the cerebral volume based on anatomical definition or functional clustering. We present the results obtained by using a two tissue-four rate constant model with two different tracers ([(11)C]FLB457 and [carbonyl-(11)C]WAY100635), one of the most complex models used in receptor studies, especially at the voxel level. H-BFM is robust and its application on both [(11)C]FLB457 and [carbonyl-(11)C]WAY100635 allows accurate and precise parameter estimates, good quality parametric maps and a low percentage of voxels out of physiological bound (<8%). The computational time depends on the number of basis functions selected and can be compatible with clinical use (~6h for a single subject analysis). The novel method is a robust approach for PET quantification by using compartmental modeling at the voxel level. In particular, different from other proposed approaches, this method can also be used when the linearization of the model is not appropriate. We expect that applying it to clinical data will generate reliable parametric maps.
Assuntos
Encéfalo/metabolismo , Modelos Neurológicos , Piperazinas/farmacocinética , Tomografia por Emissão de Pósitrons/métodos , Piridinas/farmacocinética , Pirrolidinas/farmacocinética , Receptor 5-HT1A de Serotonina/metabolismo , Receptores Dopaminérgicos/metabolismo , Salicilamidas/farmacocinética , Encéfalo/diagnóstico por imagem , Radioisótopos de Carbono/farmacocinética , Simulação por Computador , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Compostos Radiofarmacêuticos/farmacocinética , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Prasugrel is a third-generation thienopyridine which selectively inhibits the platelet P2Y(12) receptor more rapidly, more potently, and with less interindividual response variability compared with the second-generation thienopyridine clopidogrel. Large-scale phase III clinical testing showed that in high-to moderate-risk acute coronary syndrome patients undergoing percutaneous coronary intervention, prasugrel translates into a greater reduction in ischemic events, including stent thrombosis, in the short and long term compared to clopidogrel. Prasugrel, however, is associated with an increased risk of major bleeding, which is more pronounced in certain patient subgroups. The ideal patient population for prasugrel use are those patients without prior transient ischemic attack/stroke, <75 years of age and >60 kg in whom the greatest ischemic benefit is achieved without a significant increase in major bleeding risk. Dose modifications in specific populations or at given time-points may represent an avenue to minimize bleeding risk and therefore maximize the clinical benefit of prasugrel. Ongoing clinical studies with prasugrel will better define the safety and efficacy profiles of this agent and potentially set the basis for new indications for use.
Assuntos
Síndrome Coronariana Aguda/tratamento farmacológico , Piperazinas/uso terapêutico , Antagonistas do Receptor Purinérgico P2Y/uso terapêutico , Tiofenos/uso terapêutico , Angioplastia Coronária com Balão , Hidrocarboneto de Aril Hidroxilases/fisiologia , Ensaios Clínicos como Assunto , Análise Custo-Benefício , Citocromo P-450 CYP2C19 , Angiopatias Diabéticas/tratamento farmacológico , Interações Medicamentosas , Humanos , Seleção de Pacientes , Piperazinas/administração & dosagem , Piperazinas/efeitos adversos , Piperazinas/economia , Piperazinas/metabolismo , Piperazinas/farmacocinética , Agregação Plaquetária/efeitos dos fármacos , Cloridrato de Prasugrel , Antagonistas do Receptor Purinérgico P2Y/efeitos adversos , Antagonistas do Receptor Purinérgico P2Y/economia , Antagonistas do Receptor Purinérgico P2Y/metabolismo , Antagonistas do Receptor Purinérgico P2Y/farmacocinética , Recidiva , Tiofenos/administração & dosagem , Tiofenos/efeitos adversos , Tiofenos/economia , Tiofenos/metabolismo , Tiofenos/farmacocinéticaAssuntos
Substituição de Medicamentos/métodos , Hiperprolactinemia , Piperazinas , Quinolonas , Risperidona , Esquizofrenia/tratamento farmacológico , Adulto , Antipsicóticos/administração & dosagem , Antipsicóticos/efeitos adversos , Antipsicóticos/farmacocinética , Aripiprazol , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/efeitos adversos , Preparações de Ação Retardada/farmacocinética , Monitoramento de Medicamentos , Feminino , Humanos , Hiperprolactinemia/induzido quimicamente , Hiperprolactinemia/terapia , Conduta do Tratamento Medicamentoso , Farmacovigilância , Piperazinas/administração & dosagem , Piperazinas/efeitos adversos , Piperazinas/farmacocinética , Quinolonas/administração & dosagem , Quinolonas/efeitos adversos , Quinolonas/farmacocinética , Risperidona/administração & dosagem , Risperidona/efeitos adversos , Risperidona/farmacocinética , Resultado do TratamentoRESUMO
Eszopiclone is the single (S)-enantiomer of the cyclopyrrolone hypnotic zopiclone. It was marketed in the U.S. in December 2004. Its kinetics and possible mode of action, pivotal regulatory trials and its use in insomnia comorbid with other conditions are reviewed, together with trials in patients with obstructive sleep apnea syndromes. Safety and tolerability aspects are discussed, including its dysgeusic profile and effects on memory, cognitive and psychomotor function. U.S.-based pharmacoeconomic data are included together with the design features of key regulatory studies submitted for regulatory approval in Japan.
Assuntos
Compostos Azabicíclicos/uso terapêutico , Hipnóticos e Sedativos/uso terapêutico , Piperazinas/uso terapêutico , Distúrbios do Início e da Manutenção do Sono/tratamento farmacológico , Adulto , Idoso , Animais , Compostos Azabicíclicos/efeitos adversos , Compostos Azabicíclicos/química , Compostos Azabicíclicos/economia , Compostos Azabicíclicos/farmacocinética , Ensaios Clínicos como Assunto , Cognição/efeitos dos fármacos , Aprovação de Drogas , Zopiclona , Humanos , Hipnóticos e Sedativos/efeitos adversos , Hipnóticos e Sedativos/química , Hipnóticos e Sedativos/farmacologia , Japão , Memória/efeitos dos fármacos , Pessoa de Meia-Idade , Piperazinas/efeitos adversos , Piperazinas/química , Piperazinas/economia , Piperazinas/farmacocinética , Ensaios Clínicos Controlados Aleatórios como Assunto , Apneia Obstrutiva do Sono/tratamento farmacológicoRESUMO
INTRODUCTION: Occupancy-over-time was determined for two dopamine transporter (DAT) inhibitors through modeling of their ability to displace the PET ligand [(11)C]CIT. The tracer was held at a pseudo steady state in a reference tissue by target controlled infusion. METHODS: Rhesus monkeys (n = 5) were given [(11)C]CIT and studied with a PET scanner. Tracer uptake in the reference tissue cerebellum was held at a pseudo steady state by use of target controlled infusion. The pharmacokinetics/pharmacodynamics(PK/PD) of [(11)C]CIT was assessed through the simplified reference tissue model (SRTM). Bupropion (n = 2) and GBR-12909 (n = 2) receptor occupancies were estimated through modeling of their effects on [(11)C]CIT displacement. RESULTS: There was a high uptake of [(11)C]CIT in striatum, which contains a high DAT density. The reference tissue cerebellum had a comparatively low uptake. The modeling of [(11)C]CIT PK/PD properties in striatum showed high binding potential (BP = 5.34 ± 0.78). Both DAT inhibitors caused immediate displacement of [(11)C]CIT after administration. The occupancy-over-time was modeled as a mono-exponential function, describing initial maximal occupancy (Occ(0)) and rate of ligand-receptor dissociation (k(off)). GBR-12909 showed irreversible binding (k(off) = 0) after an initial occupancy of 76.1%. Bupropion had a higher initial occupancy (84.5%) followed by a release half-life of 33 minutes (k(off) = 0.021). CONCLUSIONS: The proposed model can be used for assessment of in-vivo occupancy-over-time of DAT ligands by use of target controlled infusion of [(11)C]CIT. The concept of assessing drug-receptor interactions by studying perturbations of a PET tracer from a pseudo steady state can be transferred to other CNS systems.
Assuntos
Proteínas da Membrana Plasmática de Transporte de Dopamina/antagonistas & inibidores , Compostos Radiofarmacêuticos/farmacocinética , Animais , Bupropiona/farmacocinética , Bupropiona/farmacologia , Isótopos de Carbono , Corpo Estriado/metabolismo , Feminino , Meia-Vida , Macaca mulatta , Piperazinas/farmacocinética , Piperazinas/farmacologia , Tomografia por Emissão de PósitronsRESUMO
A critical event in the apoptotic cascade is the proteolytic activation of procaspases to active caspases. The caspase autoactivating compound PAC-1 induces cancer cell apoptosis and exhibits antitumor activity in murine xenograft models when administered orally as a lipid-based formulation or implanted s.c. as a cholesterol pellet. However, high doses of PAC-1 were found to induce neurotoxicity, prompting us to design and assess a novel PAC-1 derivative called S-PAC-1. Similar to PAC-1, S-PAC-1 activated procaspase-3 and induced cancer cell apoptosis. However, S-PAC-1 did not induce neurotoxicity in mice or dogs. Continuous i.v. infusion of S-PAC-1 in dogs led to a steady-state plasma concentration of â¼10 µmol/L for 24 to 72 hours. In a small efficacy trial of S-PAC-1, evaluation of six pet dogs with lymphoma revealed that S-PAC-1 was well tolerated and that the treatments induced partial tumor regression or stable disease in four of six subjects. Our results support this canine setting for further evaluation of small-molecule procaspase-3 activators, including S-PAC-1, a compound that is an excellent candidate for further clinical evaluation as a novel cancer chemotherapeutic.
Assuntos
Doenças do Cão/tratamento farmacológico , Hidrazonas/farmacologia , Linfoma de Células B/veterinária , Piperazinas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Doenças do Cão/enzimologia , Doenças do Cão/patologia , Cães , Ativação Enzimática/efeitos dos fármacos , Células HeLa , Humanos , Hidrazonas/farmacocinética , Hidrazonas/toxicidade , Células Jurkat , Linfoma de Células B/tratamento farmacológico , Linfoma de Células B/enzimologia , Linfoma de Células B/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Piperazinas/farmacocinética , Piperazinas/toxicidade , Células U937Assuntos
Monitoramento de Medicamentos/métodos , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Leucócitos/citologia , Transportador 1 de Cátions Orgânicos/genética , Piperazinas/uso terapêutico , Pirimidinas/uso terapêutico , RNA Mensageiro/análise , Benzamidas , Monitoramento de Medicamentos/normas , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Contagem de Leucócitos , Leucócitos Mononucleares , Neutrófilos , Piperazinas/farmacocinética , Pirimidinas/farmacocinética , RNA Neoplásico/análiseRESUMO
BACKGROUND: Cardiovascular disease, including acute coronary syndromes (ACS) comprising ST-elevation and non-ST-elevation myocardial infarction (STEMI/NSTEMI) and unstable angina (UA), remains the leading cause of death in the United States. The direct and indirect costs of cardiovascular disease are estimated to surpass $165 billion in 2009. Antiplatelet pharmacotherapy has been shown to reduce ACS-related death and is part of the American College of Chest Physicians (ACCP) and the American College of Cardiology /American Heart Association (ACC/AHA) treatment guideline recommendations. OBJECTIVE: To provide formulary decision makers with information on the pharmacokinetics and pharmacodynamics of the thienopyridine antiplatelet agent prasugrel as well as an analysis of available efficacy and safety data and its risk-benefit profile in comparison with clopidogrel. METHODS: Literature search for information on prasugrel with a focus on (a) the Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition with Prasugrel-Thrombolysis in Myocardial Infarction (TRITON-TIMI) 38 trial, (b) briefing documents from the FDA available as of March 1, 2009, and (c) ongoing phase III studies of prasugrel. RESULTS: TRITON-TIMI 38 was a double blind, randomized superiority study involving 13,608 patients with moderate-to high-risk acute coronary syndromes with scheduled percutaneous coronary intervention (PCI). TRITON-TIMI 38 data were available in a published manuscript and in an FDA review. Study patients were randomized to either prasugrel or clopidogrel once daily. The primary end point (composite of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke) occurred in 643 patients (9.9%) in the prasugrel group and 781 patients (12.1%) in the clopidogrel group (HR = 0.82, 95% CI = 0.73-0.93, P = 0.002). Non-coronary artery bypass graft (non-CABG) TIMI major hemorrhage occurred in 146 patients (2.4%) in the prasugrel group compared with 111 patients (1.8%) in the clopidogrel group (HR=1.32, 95% CI=1.03-1.68, P = 0.03). A subanalysis of the TRITON-TIMI 38 trial data revealed a net harm for patients with a prior history of stroke or transient ischemic attack (TIA) when treated with prasugrel (HR = 1.54, 95% CI = 1.02-2.32, P = 0.04). Combination prasugrel and aspirin is currently being studied in comparison with clopidogrel and aspirin for the treatment of UA/NSTEMI patients that are medically managed. CONCLUSIONS: For every 1,000 patients treated with prasugrel instead of clopidogrel, a total of 24 end points would be prevented at the cost of 10 additional bleeding events. On February 3, 2009, the FDA Cardiovascular and Renal Drugs Advisory Committee deemed this to be an acceptable riskbenefit profile. The committee recommended a label contraindication for patients with prior history of transient ischemic attack or stroke. Treatment versus time analyses demonstrated both early and sustained benefit for prasugrel compared with clopidogrel. However, prasugrel was associated with fewer cardiovascular events prevented per bleeding case the longer the duration of therapy. The study population of TRITON-TIMI 38 was limited to patients undergoing PCI. Managed care decision makers should consider specific criteria limiting prasugrel use to health plan members with characteristics similar to the study population in TRITON-TIMI 38 that benefited from treatment and avoiding use in patients with prior history of stroke or TIA. More data are needed before prasugrel can be recommended in patient groups not addressed by TRITON-TIMI 38.
Assuntos
Formulários de Hospitais como Assunto/normas , Piperazinas , Inibidores da Agregação Plaquetária/uso terapêutico , Tiofenos , Angioplastia Coronária com Balão/economia , Clopidogrel , Interações Medicamentosas , Humanos , Programas de Assistência Gerenciada/economia , Infarto do Miocárdio/tratamento farmacológico , Piperazinas/efeitos adversos , Piperazinas/farmacocinética , Piperazinas/farmacologia , Piperazinas/uso terapêutico , Cloridrato de Prasugrel , Ensaios Clínicos Controlados Aleatórios como Assunto , Medição de Risco , Tiofenos/efeitos adversos , Tiofenos/farmacocinética , Tiofenos/farmacologia , Tiofenos/uso terapêutico , Ticlopidina/análogos & derivados , Ticlopidina/uso terapêuticoRESUMO
UNLABELLED: As mouse imaging has become more challenging in preclinical research, efforts have been made to develop dedicated PET systems. Although these systems are currently used for the study of physiopathologic murine models, they present some drawbacks for brain studies, including a low temporal resolution that limits the pharmacokinetic study of radiotracers. The aim of this study was to demonstrate the ability of a radiosensitive intracerebral probe to measure the binding of a radiotracer in the mouse brain in vivo. METHODS: The potential of a probe 0.25 mm in diameter for pharmacokinetic studies was assessed. First, Monte Carlo simulations followed by experimental studies were used to evaluate the detection volume and sensitivity of the probe and its adequacy for the size of loci in the mouse brain. Second, ex vivo autoradiography of 5-hydroxytryptamine receptor 1A (5-HT(1A)) receptors in the mouse brain was performed with the PET radiotracer 2'-methoxyphenyl-(N-2'-pyridinyl)-p-(18)F-fluorobenzamidoethylpiperazine ((18)F-MPPF). Finally, the binding kinetics of (18)F-MPPF were measured in vivo in both the hippocampus and the cerebellum of mice. RESULTS: Both the simulations and the experimental studies demonstrated the feasibility of using small probes to measure radioactive concentrations in specific regions of the mouse brain. Ex vivo autoradiography showed a heterogeneous distribution of (18)F-MPPF consistent with the known distribution of 5-HT(1A) in the mouse brain. Finally, the time-activity curves obtained in vivo were reproducible and validated the capacity of the new probe to accurately measure (18)F-MPPF kinetics in the mouse hippocampus. CONCLUSION: Our results demonstrate the ability of the tested radiosensitive intracerebral probe to monitor binding of PET radiotracers in anesthetized mice in vivo, with high temporal resolution suited for compartmental modeling.
Assuntos
Cerebelo/diagnóstico por imagem , Radioisótopos de Flúor , Hipocampo/diagnóstico por imagem , Piperazinas/farmacocinética , Piridinas/farmacocinética , Receptor 5-HT1A de Serotonina/metabolismo , Animais , Cerebelo/metabolismo , Simulação por Computador , Radioisótopos de Flúor/farmacocinética , Hipocampo/metabolismo , Masculino , Camundongos , Método de Monte Carlo , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos/farmacocinéticaRESUMO
Eszopiclone (Lunesta), the S-enantiomer of racemic zopiclone, is a nonbenzodiazepine hypnotic agent that is approved in the US as an oral, once-nightly therapy for insomnia in adults; eszopiclone is also currently under review by the European Medicines Agency. Eszopiclone is rapidly absorbed after oral administration without any next-day clinical residual effects being detected. Large, well designed trials of up to 6 months' duration have shown that eszopiclone significantly improves both sleep onset and sleep maintenance compared with placebo in adult and elderly patients with primary insomnia. Eszopiclone for 4-8 weeks also significantly improved sleep parameters compared with placebo in patients with insomnia coexisting with other conditions that also disturb sleep (co-morbid insomnia), and improved certain measures of the co-morbid conditions to a greater extent than the standard therapies alone. Short-term eszopiclone produced improvements in daytime functioning in patients with co-morbid insomnia. Six months' therapy in adults with primary insomnia improved daytime functioning and health-related quality of life. Eszopiclone was generally well tolerated. There was no evidence of tolerance during 12 months' treatment with this agent. On discontinuation of eszopiclone, there was no rebound insomnia or serious withdrawal effects. Well designed, comparative trials with other nonbenzodiazepine hypnotics are needed to determine its relative efficacy and tolerability. A cost-utility analysis suggested that eszopiclone is cost effective for the treatment of primary insomnia in the US. Therefore, eszopiclone is a useful therapeutic option in the management of adult and elderly patients with primary or co-morbid insomnia. Unlike most other hypnotics, eszopiclone is not limited to short-term use.
Assuntos
Compostos Azabicíclicos/administração & dosagem , Hipnóticos e Sedativos/administração & dosagem , Piperazinas/administração & dosagem , Distúrbios do Início e da Manutenção do Sono/tratamento farmacológico , Adulto , Compostos Azabicíclicos/efeitos adversos , Compostos Azabicíclicos/economia , Compostos Azabicíclicos/farmacocinética , Ensaios Clínicos como Assunto , Análise Custo-Benefício , Interações Medicamentosas , Zopiclona , Humanos , Hipnóticos e Sedativos/efeitos adversos , Hipnóticos e Sedativos/economia , Hipnóticos e Sedativos/farmacocinética , Satisfação do Paciente , Piperazinas/efeitos adversos , Piperazinas/economia , Piperazinas/farmacocinéticaRESUMO
(1) Ranolazine-- an adjunctive treatment to beta-blockers, calcium channel blockers, or long-acting nitrates-- is indicated for patients with chronic stable angina who have not responded to standard anti-anginal therapy. (2) In three randomized controlled trials (RCTs), ranolazine, in combination with standard anti-anginal medications, led to modest but statistically significant improvements in exercise duration, and reductions in the frequency of angina episodes and nitroglycerin consumption, when compared to standard anti-anginal medications only. The clinical significance of these improvements is unknown. Most of the participants in studies were male and Caucasian. Thus, there are questions about the drug's efficacy in other populations. (3) One RCT suggests that the addition of ranolazine to standard treatment is ineffective in reducing major cardiovascular events that are associated with acute coronary syndromes. (4) The adverse effects reported with ranolazine include dizziness, nausea, asthenia (weakness), constipation, and headache. Long-term data from one trial indicate that there is no significant increase in the incidence of death or arrhythmia among those taking ranolazine. More clinical trials of ranolazine are needed to confirm its long-term safety, its optimal dosing, its efficacy in combination with full dose beta-blockers with or without calcium channel blockers, and its potential role in the treatment of other cardiovascular conditions.