RESUMO
The increasing availability of prescription opioid analgesics for the treatment of pain has been paralleled by an epidemic of opioid misuse, diversion, and overdose. The development of abuse-deterrent formulations (ADFs) of conventional opioids such as oxycodone and morphine represents an advance in the field and has had a positive but insufficient impact, as most opioids are still prescribed in highly abusable, non-ADF forms, and abusers can tamper with ADF medications to liberate the abusable opioid within. The abuse liability of mu-opioid agonists appears to be dependent on their rapid rate of entry into the central nervous system (CNS), whereas analgesic activity appears to be a function of CNS exposure alone, suggesting that a new opioid agonist with an inherently low rate of influx across the blood-brain barrier could mediate analgesia with low abuse liability, regardless of formulation or route of administration. NKTR-181 is a novel, long-acting, selective mu-opioid agonist with structural properties that reduce its rate of entry across the blood-brain barrier compared with traditional mu-opioid agonists. NKTR-181 demonstrated maximum analgesic activity comparable to that of oxycodone in hot-plate latency and acetic-acid writhing models. NKTR-181 was distinguishable from oxycodone by its reduced abuse potential in self-administration and progressive-ratio break point models, with behavioral effects similar to those of saline, as well as reduced CNS side effects as measured by the modified Irwin test. The in vitro and in vivo studies presented here demonstrate that NKTR-181 is the first selective mu-opioid agonist to combine analgesic efficacy and reduced abuse liability through the alteration of brain-entry kinetics.
Assuntos
Analgésicos Opioides/farmacologia , Morfinanos/farmacologia , Transtornos Relacionados ao Uso de Substâncias/prevenção & controle , Analgésicos Opioides/química , Analgésicos Opioides/metabolismo , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Células CACO-2 , Relação Dose-Resposta a Droga , Composição de Medicamentos , Humanos , Masculino , Morfinanos/química , Morfinanos/metabolismo , Permeabilidade , Ratos , Ratos Sprague-Dawley , Receptores Opioides mu/metabolismo , Fatores de TempoRESUMO
The design synthesis and SAR of a series of chiral ring-constrained norepinephrine reuptake inhibitors with improved physicochemical properties is described. Typical compounds are potent (IC(50)s<10 nM), selective against the other monoamine transporters, weak CYP2D6 inhibitors (IC(50)s>1 microM) and stable to oxidation by human liver microsomes. In addition, the compounds exhibit a favorable polarity profile.
Assuntos
Inibidores do Citocromo P-450 CYP2D6 , Indanos/síntese química , Indanos/farmacologia , Inibidores da Captação de Neurotransmissores/síntese química , Inibidores da Captação de Neurotransmissores/farmacologia , Norepinefrina/antagonistas & inibidores , Cloridrato de Atomoxetina , Técnicas de Química Combinatória , Desenho de Fármacos , Humanos , Indanos/química , Concentração Inibidora 50 , Microssomos Hepáticos/metabolismo , Estrutura Molecular , Inibidores da Captação de Neurotransmissores/química , Propilaminas/farmacologia , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
The synthesis and SAR of a series of chiral heterocyclic ring-constrained norepinephrine reuptake inhibitors are described. The best compounds compare favorably with atomoxetine in potency (IC(50)s<10 nM), selectivity against the other monoamine transporters, and inhibition of CYP2D6 (IC(50)s>1 microM). In addition, the compounds are generally more stable than atomoxetine to oxidative metabolism and thus are likely to have lower clearance in humans.
Assuntos
Inibidores da Captação Adrenérgica/síntese química , Inibidores da Captação Adrenérgica/farmacologia , Química Farmacêutica/métodos , Proteínas da Membrana Plasmática de Transporte de Norepinefrina/síntese química , Proteínas da Membrana Plasmática de Transporte de Norepinefrina/farmacologia , Norepinefrina/química , Oxigênio/química , Inibidores da Captação Adrenérgica/química , Cloridrato de Atomoxetina , Citocromo P-450 CYP2D6/química , Desenho de Fármacos , Humanos , Concentração Inibidora 50 , Modelos Químicos , Conformação Molecular , Norepinefrina/metabolismo , Propilaminas/química , Propilaminas/farmacologia , Relação Estrutura-Atividade , Simportadores/químicaRESUMO
The design, synthesis and SAR of a series of heterocyclic ring-constrained norepinephrine reuptake inhibitors are described. As racemates, the best compounds compare favorably with atomoxetine (IC(50)'s<10 nM) in potency at the transporter.
Assuntos
Proteínas da Membrana Plasmática de Transporte de Norepinefrina/química , Cloridrato de Atomoxetina , Química Farmacêutica/métodos , Inibidores do Citocromo P-450 CYP2D6 , Citocromo P-450 CYP3A , Inibidores do Citocromo P-450 CYP3A , Desenho de Fármacos , Humanos , Indenos/farmacologia , Concentração Inibidora 50 , Microssomos Hepáticos/enzimologia , Modelos Químicos , Norepinefrina/química , Norepinefrina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Norepinefrina/metabolismo , Propilaminas/química , Serotonina/química , Relação Estrutura-AtividadeRESUMO
The design, synthesis, and SAR of a series of ring-constrained norepinephrine reuptake inhibitors are described. A substantially rigid inhibitor with potent functional activity at the transporter (IC(50)=8 nM) was used to develop a model for the distance and orientation of key features necessary for interaction with the norepinephrine transporter (NET).
Assuntos
Inibidores da Captação Adrenérgica/síntese química , Inibidores da Captação Adrenérgica/farmacologia , Proteínas da Membrana Plasmática de Transporte de Norepinefrina/síntese química , Proteínas da Membrana Plasmática de Transporte de Norepinefrina/farmacologia , Aminas/química , Cloridrato de Atomoxetina , Sítios de Ligação , Linhagem Celular , Química Farmacêutica/métodos , Desipramina/química , Desenho de Fármacos , Humanos , Concentração Inibidora 50 , Modelos Químicos , Conformação Molecular , Propilaminas/química , Relação Estrutura-AtividadeRESUMO
Over the past decade, there have been major advances in our understanding of the role of glutamate and N-methyl-d-aspartate (NMDA) receptors in several disorders of the central nervous system, including stroke, Parkinson's disease, Huntington's disease and chronic/neuropathic pain. In particular, NR2B subunit-containing NMDA receptors have been the focus of intense study from both a physiological and a pharmacological perspective, with several pharmaceutical companies developing NR2B subtype-selective antagonists for several glutamate-mediated diseases. Recent studies have shown the importance of NR2B subunits for NMDA receptor localization and endocytosis, and have suggested a role for NR2B-containing NMDA receptors in the underlying pathophysiology of neurodegenerative disorders such as Alzheimer's and Huntington's diseases. Anatomical, biochemical and pharmacological studies over the past five years have greatly added to our understanding of the role of NR2B subunit-containing NMDA receptors in chronic and neuropathic pain states, and have shown that NR2B-mediated analgesic effects might be supra- rather than intra-spinally mediated, and that phosphorylation of the NR2B subunit could be responsible for the initiation and maintenance of the central sensitization seen in neuropathic pain states. These data will hopefully provide the impetus for development of novel compounds that use multiple approaches to modulate the activity of NR2B subunit-containing NMDA receptors, thus bringing to fruition the promise of therapeutic efficacy utilizing this approach.
Assuntos
Isquemia Encefálica/tratamento farmacológico , Antagonistas de Aminoácidos Excitatórios/uso terapêutico , Doença de Huntington/tratamento farmacológico , Dor/tratamento farmacológico , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Animais , Isquemia Encefálica/metabolismo , Ensaios Clínicos como Assunto , Modelos Animais de Doenças , Antagonistas de Aminoácidos Excitatórios/farmacologia , Ácido Glutâmico/metabolismo , Humanos , Doença de Huntington/metabolismo , Dor/metabolismo , Fenóis/farmacologia , Fenóis/uso terapêutico , Piperidinas/farmacologia , Piperidinas/uso terapêutico , Conformação Proteica , Receptores de N-Metil-D-Aspartato/metabolismoRESUMO
The melanocortin-4 receptor (MC4R) plays an important role in the regulation of energy homeostasis. Recent studies have shown that blockade of the MC4R reverses tumor-induced weight loss in mice. Herein, we describe the synthesis and identification of potent and selective non-peptide antagonists of the human MC4R from a series of 2-ethoxycarbonylcyclohexyl-piperazines. Compound 12i was found to possess low nanomolar affinity for the MC4R, and exhibit oral bioavailability in rats. More importantly, when administered orally to mice (10 mg/kg), it led to statistically significant increases in food intake over a 24-h period.
Assuntos
Piperazinas/síntese química , Receptor Tipo 4 de Melanocortina/antagonistas & inibidores , Administração Oral , Animais , Disponibilidade Biológica , Caquexia/tratamento farmacológico , Ingestão de Alimentos/efeitos dos fármacos , Humanos , Piperazinas/farmacocinética , Piperazinas/farmacologia , Ligação Proteica , Ratos , Relação Estrutura-AtividadeRESUMO
Derivatives of 1-(4-amino-phenyl)-pyrrolidin-3-yl-amine and 6-(3-amino-pyrrolidin-1-yl)-pyridin-3-yl-amine were identified as potent and functionally active MCH-R1 antagonists. One compound with Ki = 2.3 nM demonstrated good oral bioavailability (32%) and in vivo efficacy in rats.
Assuntos
Piridinas/farmacologia , Pirrolidinas/farmacologia , Receptores de Somatostatina/antagonistas & inibidores , Administração Oral , Animais , Disponibilidade Biológica , Peso Corporal , Avaliação Pré-Clínica de Medicamentos , Humanos , Masculino , Modelos Animais , Estrutura Molecular , Piridinas/química , Piridinas/farmacocinética , Pirrolidinas/química , Pirrolidinas/farmacocinética , Ratos , Ratos Wistar , Receptores de Somatostatina/metabolismo , Relação Estrutura-AtividadeRESUMO
Indiplon (NBI 34060; N-methyl-N-[3-[3-(2-thienylcarbonyl)-pyrazolo[1,5-alpha]pyrimidin-7-yl]phenyl]acetamide), a novel pyrazolopyrimidine and high-affinity allosteric potentiator of GABA(A) receptor function, was profiled for its effects in rodents after oral administration. In mice, indiplon inhibited locomotor activity (ED(50) = 2.7 mg/kg p.o.) at doses lower than the nonbenzodiazepine hypnotics zolpidem (ED(50) = 6.1 mg/kg p.o.) and zaleplon (ED(50) = 24.6 mg/kg p.o.), a sedative effect that was reversed by the benzodiazepine site antagonist flumazenil. Indiplon inhibited retention in the mouse passive avoidance paradigm over a dose range and with a temporal profile that coincided with its sedative activity. Indiplon, zolpidem, and zaleplon were equally effective in inhibiting locomotor activity in the rat and produced dose-related deficits on the rotarod. In a rat vigilance paradigm, indiplon, zolpidem, and zaleplon produced performance deficits over a dose range consistent with their sedative effects, although indiplon alone showed no significant increase in response latency. Indiplon produced a small deficit in the delayed nonmatch to sample paradigm at a dose where sedative effects became apparent. Indiplon was active in the rat Vogel test of anxiety, but it showed only a sedative profile in the mouse open field test. The pharmacokinetic profile of indiplon in both rat and mouse was consistent with its pharmacodynamic properties and indicated a rapid T(max), short t(1/2), and excellent blood-brain barrier penetration. Therefore, indiplon has the in vivo profile of an efficacious sedative-hypnotic, in agreement with its in vitro receptor pharmacology as a high-affinity allosteric potentiator of GABA(A) receptor function, with selectivity for alpha1 subunit-containing GABA(A) receptors.