RESUMO
The aim of this study was to assess blood free naltrexone and 6-beta-naltrexol levels with time following treatment with sequential sustained-release naltrexone preparations. Data were collected from blood samples analysed independently for naltrexone and 6-beta-naltrexol and from clinical record review at a community heroin treatment clinic in Perth, Western Australia. Five patients received sequential 3.4 g (3.49+/-0.01 g and 3.36+/-0.05 g, respectively) naltrexone implants. The second implant was received on average within 131.2+/-15.67 days of the first implant. The mean length of follow-up was 307.2+/-18.28 days of the first implant. Blood naltrexone levels have the potential to remain above 2 and 1 ng/ml for a total of 390 and 524 days, respectively, and blood 6-beta-naltrexol was maintained above 10 ng/ml for a total of 222 days following insertion of these implants. No patient relapsed to dependent heroin use during the implant coverage period while blood naltrexone concentrations were above 2 ng/ml. Results indicate that blood naltrexone and 6-beta-naltrexol levels can be maintained above therapeutic levels for prolonged periods following use of sequential 3.4 g naltrexone implants. These extended periods of coverage will offer significant benefits for managing the heroin-dependent patient.
Assuntos
Dependência de Heroína/tratamento farmacológico , Naltrexona/administração & dosagem , Naltrexona/sangue , Antagonistas de Entorpecentes/administração & dosagem , Antagonistas de Entorpecentes/sangue , Adulto , Índice de Massa Corporal , Estudos de Coortes , Preparações de Ação Retardada , Esquema de Medicação , Implantes de Medicamento , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Naltrexona/análogos & derivados , Naltrexona/uso terapêutico , Antagonistas de Entorpecentes/uso terapêutico , Estudos Retrospectivos , Fatores de TempoRESUMO
The aim of this study was to profile and compare blood naltrexone and 6-beta-naltrexol levels with time following treatment with two sustained-release naltrexone preparations produced by GoMedical Industries, Australia at a community heroin treatment clinic in Perth, Western Australia. A sample of 10 patients who each received a 1.7 g naltrexone implant were compared to 24 patients who each received a 3.4 g naltrexone implant as treatment for heroin dependence. Blood naltrexone levels following treatment with the 1.7 g naltrexone implant remained above 2 and 1 ng/ml for approximately 90 and 136 days, respectively. Use of the 3.4 g naltrexone implant extended the period of coverage to approximately 297 (1 ng/ml) or 188 (2 ng/ml) days. Blood 6-beta-naltrexol levels remained above 10 ng/ml for approximately 18 and 83 days, respectively, following use of the 1.7 g and 3.4 g naltrexone implants. The current study data indicate that blood naltrexone and 6-beta-naltrexol levels following treatment with either the 1.7 g or 3.4 g naltrexone implant are greater than those reported in other published data on other sustained-release naltrexone preparations. Furthermore, duration of blood naltrexone and 6-beta-naltrexol levels achieved following use of the 3.4 g implant were superior to those achieved with the 1.7 g naltrexone implant, with naltrexone blood levels maintained above 2 ng/ml for a period of approximately 6.3 months compared to 3 months, respectively. The implications of this in managing the heroin-dependent patient, especially those who find it difficult to shift away from dependent use patterns, are discussed.
Assuntos
Dependência de Heroína/sangue , Dependência de Heroína/tratamento farmacológico , Naltrexona/administração & dosagem , Naltrexona/sangue , Antagonistas de Entorpecentes/administração & dosagem , Antagonistas de Entorpecentes/sangue , Adulto , Índice de Massa Corporal , Preparações de Ação Retardada , Esquema de Medicação , Implantes de Medicamento , Feminino , Seguimentos , Humanos , Masculino , Naltrexona/análogos & derivados , Naltrexona/uso terapêutico , Antagonistas de Entorpecentes/uso terapêutico , Estudos RetrospectivosRESUMO
We show theoretically and experimentally that photonic band gaps can be realized using metal or metal-coated spheres as building blocks. Robust photonic gaps exist in any periodic structure built from such spheres when the filling ratio of the spheres exceeds a threshold. The frequency and the size of the gaps depend on the local order rather than on the symmetry or the global long range order. Good agreement between theory and experiment is obtained in the microwave regime. Calculations show that the approach can be scaled up to optical frequencies even in the presence of absorption.
RESUMO
We have fabricated sonic crystals, based on the idea of localized resonant structures, that exhibit spectral gaps with a lattice constant two orders of magnitude smaller than the relevant wavelength. Disordered composites made from such localized resonant structures behave as a material with effective negative elastic constants and a total wave reflector within certain tunable sonic frequency ranges. A 2-centimeter slab of this composite material is shown to break the conventional mass-density law of sound transmission by one or more orders of magnitude at 400 hertz.