RESUMEN
Context: Resilience is the ability to deal with shocks and stresses, including the unknown and previously unimaginable, such as the Covid-19 crisis. Objective: This paper assesses (i) how different farming systems were exposed to the crisis, (ii) which resilience capacities were revealed and (iii) how resilience was enabled or constrained by the farming systems' social and institutional environment. Methods: The 11 farming systems included have been analysed since 2017. This allows a comparison of pre-Covid-19 findings and the Covid-19 crisis. Pre-Covid findings are from the SURE-Farm systematic sustainability and resilience assessment. For Covid-19 a special data collection was carried out during the early stage of lockdowns. Results and conclusions: Our case studies found limited impact of Covid-19 on the production and delivery of food and other agricultural products. This was due to either little exposure or the agile activation of robustness capacities of the farming systems in combination with an enabling institutional environment. Revealed capacities were mainly based on already existing connectedness among farmers and more broadly in value chains. Across cases, the experience of the crisis triggered reflexivity about the operation of the farming systems. Recurring topics were the need for shorter chains, more fairness towards farmers, and less dependence on migrant workers. However, actors in the farming systems and the enabling environment generally focused on the immediate issues and gave little real consideration to long-term implications and challenges. Hence, adaptive or transformative capacities were much less on display than coping capacities. The comparison with pre-Covid findings mostly showed similarities. If challenges, such as shortage of labour, already loomed before, they persisted during the crisis. Furthermore, the eminent role of resilience attributes was confirmed. In cases with high connectedness and diversity we found that these system characteristics contributed significantly to dealing with the crisis. Also the focus on coping capacities was already visible before the crisis. We are not sure yet whether the focus on short-term robustness just reflects the higher visibility and urgency of shocks compared to slow processes that undermine or threaten important system functions, or whether they betray an imbalance in resilience capacities at the expense of adaptability and transformability. Significance: Our analysis indicates that if transformations are required, e.g. to respond to concerns about transnational value chains and future pandemics from zoonosis, the transformative capacity of many farming systems needs to be actively enhanced through an enabling environment.
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Perrault syndrome is a rare autosomal recessive disorder characterized by sensorineural hearing loss (SNHL) in both sexes and primary ovarian insufficiency in 46, XX karyotype females. Biallelic variants in five genes are reported to be causative: HSD17B4, HARS2, LARS2, CLPP and C10orf2. Here we present eight families affected by Perrault syndrome. In five families we identified novel or previously reported variants in HSD17B4, LARS2, CLPP and C10orf2. The proband from each family was whole exome sequenced and variants confirmed by Sanger sequencing. A female was compound heterozygous for a known, p.(Gly16Ser) and novel, p.(Val82Phe) variant in D-bifunctional protein (HSD17B4). A family was homozygous for mitochondrial leucyl aminocyl tRNA synthetase (mtLeuRS) (LARS2) p.(Thr522Asn), previously associated with Perrault syndrome. A further family was compound heterozygous for mtLeuRS, p.(Thr522Asn) and a novel variant, p.(Met117Ile). Affected individuals with LARS2 variants had low frequency SNHL, a feature previously described in Perrault syndrome. A female with significant neurological disability was compound heterozygous for p.(Arg323Gln) and p.(Asn399Ser) variants in Twinkle (C10orf2). A male was homozygous for a novel variant in CLPP, p.(Cys144Arg). In three families there were no putative pathogenic variants in these genes confirming additional disease-causing genes remain unidentified. We have expanded the spectrum of disease-causing variants associated with Perrault syndrome.
Asunto(s)
Aminoacil-ARNt Sintetasas/genética , ADN Helicasas/genética , Endopeptidasa Clp/genética , Disgenesia Gonadal 46 XX/genética , Pérdida Auditiva Sensorineural/genética , Proteínas Mitocondriales/genética , Proteína-2 Multifuncional Peroxisomal/genética , Exoma/genética , Femenino , Genotipo , Disgenesia Gonadal 46 XX/patología , Pérdida Auditiva Sensorineural/patología , Homocigoto , Humanos , Masculino , Mutación , Linaje , Fenotipo , Insuficiencia Ovárica Primaria/genética , Insuficiencia Ovárica Primaria/fisiopatologíaRESUMEN
Lissencephaly is a phenotypically and genetically heterogeneous group of cortical brain malformations due to abnormal neuronal migration. The identification of many causative genes has increased the understanding of normal brain development. A consanguineous family was ascertained with three siblings affected by a severe prenatal neurodevelopmental disorder characterised by fronto-parietal pachygyria, agenesis of the corpus callosum and progressive severe microcephaly. Autozygosity mapping and exome sequencing identified a homozygous novel single base pair deletion, c.1197delT in DMRTA2, predicted to result in a frameshift variant p.(Pro400Leufs*33). DMRTA2 encodes doublesex and mab-3-related transcription factor a2, a transcription factor key to the development of the dorsal telencephalon. Data from murine and zebrafish knockout models are consistent with the variant of DMTRA2 (DMRT5) as responsible for the cortical brain phenotype. Our study suggests that loss of function of DMRTA2 leads to a novel disorder of cortical development.
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Corteza Cerebral/anomalías , Predisposición Genética a la Enfermedad/genética , Lisencefalia/genética , Mutación , Animales , Secuencia de Bases , Consanguinidad , Modelos Animales de Enfermedad , Exoma/genética , Salud de la Familia , Femenino , Humanos , Masculino , Ratones , Linaje , Análisis de Secuencia de ADN/métodos , Hermanos , Factores de Transcripción , Xenopus/genética , Pez Cebra/genéticaRESUMEN
Drugs that provide long durations of action after a last-taken dose are said to be "forgiving," as they allow the patient a degree of latitude in the timing of sequential doses. New research, by Assawasuwannakit et al.,(1) based on exemplary methods, enriches the pharmacometric analysis of forgiveness, which for several decades had been a simply descriptive reminder that the beneficial actions of some drugs can continue for hours or days after the disappearance of detectable drug.
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Atorvastatina/administración & dosificación , Cálculo de Dosificación de Drogas , Inhibidores de Hidroximetilglutaril-CoA Reductasas/administración & dosificación , Cumplimiento de la Medicación , Modelos Estadísticos , Omeprazol/administración & dosificación , Inhibidores de la Bomba de Protones/administración & dosificación , HumanosRESUMEN
Adherence to rationally prescribed medications is essential for effective pharmacotherapy. However, widely variable adherence to protocol-specified dosing regimens is prevalent among participants in ambulatory drug trials, mostly manifested in the form of underdosing. Drug actions are inherently dose and time dependent, and as a result, variable underdosing diminishes the actions of trial medications by various degrees. The ensuing combination of increased variability and decreased magnitude of trial drug actions reduces statistical power to discern between-group differences in drug actions. Variable underdosing has many adverse consequences, some of which can be mitigated by the combination of reliable measurements of ambulatory patients' adherence to trial and nontrial medications, measurement-guided management of adherence, statistically and pharmacometrically sound analyses, and modifications in trial design. Although nonadherence is prevalent across all therapeutic areas in which the patients are responsible for treatment administration, the significance of the adverse consequences depends on the characteristics of both the disease and the medications.
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Ensayos Clínicos como Asunto/estadística & datos numéricos , Cumplimiento de la Medicación/estadística & datos numéricos , Ensayos Clínicos como Asunto/métodos , Documentación , Diseño de Fármacos , Monitoreo de Drogas , Electrónica , Humanos , Cooperación del Paciente , FarmacocinéticaRESUMEN
Interest in patient adherence has increased in recent years, with a growing literature that shows the pervasiveness of poor adherence to appropriately prescribed medications. However, four decades of adherence research has not resulted in uniformity in the terminology used to describe deviations from prescribed therapies. The aim of this review was to propose a new taxonomy, in which adherence to medications is conceptualized, based on behavioural and pharmacological science, and which will support quantifiable parameters. A systematic literature review was performed using MEDLINE, EMBASE, CINAHL, the Cochrane Library and PsycINFO from database inception to 1 April 2009. The objective was to identify the different conceptual approaches to adherence research. Definitions were analyzed according to time and methodological perspectives. A taxonomic approach was subsequently derived, evaluated and discussed with international experts. More than 10 different terms describing medication-taking behaviour were identified through the literature review, often with differing meanings. The conceptual foundation for a new, transparent taxonomy relies on three elements, which make a clear distinction between processes that describe actions through established routines ('Adherence to medications', 'Management of adherence') and the discipline that studies those processes ('Adherence-related sciences'). 'Adherence to medications' is the process by which patients take their medication as prescribed, further divided into three quantifiable phases: 'Initiation', 'Implementation' and 'Discontinuation'. In response to the proliferation of ambiguous or unquantifiable terms in the literature on medication adherence, this research has resulted in a new conceptual foundation for a transparent taxonomy. The terms and definitions are focused on promoting consistency and quantification in terminology and methods to aid in the conduct, analysis and interpretation of scientific studies of medication adherence.
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Monitoreo de Drogas/clasificación , Cumplimiento de la Medicación , Manejo de Atención al Paciente/clasificación , Preparaciones Farmacéuticas/clasificación , Bases de Datos Factuales , Manejo de la Enfermedad , HumanosRESUMEN
AIM: To determine the effects of imperfect adherence (i.e. occasionally missing prescribed doses), and the influence of rate of loss of antihypertensive effect during treatment interruption, on the predicted clinical effectiveness of antihypertensive drugs in reducing mean systolic blood pressure (SBP) and cardiovascular disease (CVD) risk. METHOD: The effects of imperfect adherence to antihypertensive treatment regimens were estimated using published patterns of missed doses, and taking into account the rate of loss of antihypertensive effect when doses are missed (loss of BP reduction in mmHg/day; the off-rate), which varies between drugs. Outcome measures were the predicted mean SBP reduction and CVD risk, determined from the Framingham Risk Equation for CVD. RESULTS: In patients taking 75% of prescribed doses (typical of clinical practice), only long-acting drugs with an off-rate of â¼1 mmHg/day were predicted to maintain almost the full mean SBP-lowering effect throughout the modelled period. In such patients, using shorter-acting drugs (e.g. an off-rate of â¼5-6 mmHg/day) was predicted to lead to a clinically relevant loss of mean SBP reduction of > 2 mmHg. This change also influenced the predicted CVD risk reduction; in patients with a baseline 10-year CVD risk of 27.0% and who were taking 75% of prescribed doses, a difference in off-rate from 1 to 5 mmHg/day led to a predicted 0.5% absolute increase in 10-year CVD risk. CONCLUSIONS: In patients who occasionally miss doses of antihypertensives, modest differences in the rate of loss of antihypertensive effect following treatment interruption may have a clinically relevant impact on SBP reduction and CVD risk. While clinicians must make every effort to counsel and encourage each of their patients to adhere to their prescribed medication, it may also be prudent to prescribe drugs with a low off-rate to mitigate the potential consequences of missing doses.
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Antihipertensivos/administración & dosificación , Hipertensión/tratamiento farmacológico , Anciano , Enfermedades Cardiovasculares/etiología , Esquema de Medicación , Femenino , Humanos , Masculino , Cumplimiento de la Medicación , Medicamentos bajo Prescripción/uso terapéutico , Medición de Riesgo , Factores de Riesgo , Factores de TiempoRESUMEN
The usual objective during long-term pharmacotherapy is, in large part, to maintain continuity of action of the prescribed drug(s). Continuity of action arises from the continuity of execution of a prescribed dosing regimen that is pharmacologically sound in dose quantity and interval between successive doses. Interruptions in dosing can interrupt drug action, but the consequences vary according to length of interruption, drug, drug formulation, length of the patient's prior exposure to the drug, and the disease being treated.
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Enfermedad Crónica/tratamiento farmacológico , Cumplimiento de la Medicación , Medicamentos bajo Prescripción/farmacocinética , Medicamentos bajo Prescripción/uso terapéutico , Antagonistas Adrenérgicos beta/administración & dosificación , Antagonistas Adrenérgicos beta/farmacocinética , Fármacos Anti-VIH/administración & dosificación , Fármacos Anti-VIH/farmacocinética , Antihipertensivos/administración & dosificación , Antihipertensivos/farmacocinética , Relación Dosis-Respuesta a Droga , Infecciones por VIH/tratamiento farmacológico , Humanos , Hipertensión/tratamiento farmacológico , Medicamentos bajo Prescripción/administración & dosificación , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
Biallelic inactivation of the NF2 gene occurs in the majority of schwannomas. This usually involves a combination of a point mutation or multiexon deletion, in conjunction with either a second point mutation or loss of heterozygosity (LOH). We have performed DNA sequence and dosage analysis of the NF2 gene in a panel of 239 schwannoma tumours: 97 neurofibromatosis type 2 (NF2)-related schwannomas, 104 sporadic vestibular schwannomas (VS) and 38 schwannomatosis-related schwannomas. In total, we identified germline NF2 mutations in 86 out of 97 (89%) NF2 patients and a second mutational event in 77 out of 97 (79%). LOH was by far the most common form of second hit. A combination of microsatellite analysis with either conventional comparative genomic hybridization (CGH) or multiplex ligation-dependent probe amplification (MLPA) identified mitotic recombination (MR) as the cause of LOH in 14 out of 72 (19%) total evaluable tumours. Among sporadic VS, at least one NF2 mutation was identified by sequence analysis or MLPA in 65 out of 98 (66%) tumours. LOH occurred in 54 out of 96 (56%) evaluable tumours, but MR only accounted for 5 out of 77 (6%) tested. LOH was present in 28 out of 34 (82%) schwannomatosis-related schwannomas. In all eight patients who had previously tested positive for a germline SMARCB1 mutation, this involved loss of the whole, or part of the long arm, of chromosome 22. In contrast, 5 out of 22 (23%) tumours from patients with no germline SMARCB1 mutation exhibited MR. High-resolution Affymetrix SNP6 genotyping and copy number (CN) analysis (Affymetrix, Santa Clara, CA, USA) were used to determine the chromosomal breakpoint locations in tumours with MR. A range of unique recombination sites, spanning approximately 11.4 Mb, were identified. This study shows that MR is a mechanism of LOH in NF2 and SMARCB1-negative schwannomatosis-related schwannomas, occurring less frequently in sporadic VS. We found no evidence of MR in SMARCB1-positive schwannomatosis, suggesting that susceptibility to MR varies according to the disease context.
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Pérdida de Heterocigocidad/genética , Mitosis/genética , Neurofibromatosis 2/genética , Recombinación Genética/genética , Adolescente , Adulto , Niño , Puntos de Rotura del Cromosoma , Dosificación de Gen/genética , Genes de la Neurofibromatosis 2 , Homocigoto , Humanos , Neurilemoma/genética , Neurofibromatosis/genética , Polimorfismo de Nucleótido Simple/genética , Neoplasias Cutáneas/genética , Adulto JovenRESUMEN
Autosomal dominant vitreoretinochoroidopathy (ADVIRC), a retinal dystrophy often associated with glaucoma and cataract, forms part of a phenotypic spectrum of 'bestrophinopathies'. It has been shown previously that ADVIRC results from BEST1 mutations that cause exon skipping and lead to the production of shortened and internally deleted isoforms. This study describes a novel ADVIRC mutation and show that it disrupts an exonic splice enhancer (ESE) site, altering the binding of a splicing-associated SR protein. As with previous ADVIRC mutations, the novel c.704T-->C mutation in exon 6 altered normal splicing in an ex vivo splicing assay. Both this and another exon 6 ADVIRC-causing mutation (c.707G-->A) either weakened or abolished splicing in an ESE-dependent splice assay compared with a nearby exon 6 mutation associated with Best disease (c.703G-->C). Gel shift assays were undertaken with RNA oligonucleotides encompassing the ADVIRC and Best disease mutations with four of the most commonly investigated SR proteins. Although SC35, SRp40 and SRp55 proteins all bound to the wild-type and mutated sequences with similar intensities, there was increased binding of ASF/SF2 to the two ADVIRC-mutated sequences compared with the wild-type or Best disease-mutated sequences. The exon skipping seen for these two exon 6 ADVIRC mutations and their affinity for ASF/SF2 suggests that the region encompassing these mutations may form part of a CERES (composite exonic regulatory elements of splicing) site.
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Canales de Cloruro/genética , Enfermedades de la Coroides/genética , Proteínas del Ojo/genética , Mutación , Empalme del ARN/genética , Enfermedades de la Retina/genética , Adulto , Secuencia de Bases , Bestrofinas , Canales de Cloruro/metabolismo , Enfermedades de la Coroides/metabolismo , Exones , Proteínas del Ojo/metabolismo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Linaje , Unión Proteica , ARN Mensajero/genética , Enfermedades de la Retina/metabolismo , Alineación de SecuenciaRESUMEN
Modern information technology offers efficiencies in medical practice, with a reduction in secretarial time in maintaining, filing and retrieving the paper medical record. Electronic requesting of investigations allows tracking of outstanding results. Less storage space is required and telephone calls from pharmacies, pathology and medical imaging service providers to clarify the hand-written request are abolished. Voice recognition software reduces secretarial typing time per letter. These combined benefits can lead to significantly reduced costs and improved patient care. The paperless office is possible, but requires commitment and training of all staff; it is preferable but not absolutely essential that at least one member of the practice has an interest and some expertise in computers. More importantly, back-up from information technology providers and back-up of the electronic data are absolutely crucial and a paperless environment should not be considered without them.
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Computadores/normas , Sistemas de Registros Médicos Computarizados/normas , Administración de la Práctica Médica/normas , Seguridad Computacional/normas , Seguridad Computacional/tendencias , Computadores/tendencias , Humanos , Almacenamiento y Recuperación de la Información/normas , Almacenamiento y Recuperación de la Información/tendencias , Sistemas de Registros Médicos Computarizados/tendencias , Administración de la Práctica Médica/tendencias , Programas Informáticos/normas , Programas Informáticos/tendenciasRESUMEN
Pneumocephalus is a rare complication of epidural block which typically occurs when the loss of resistance to air technique is used to identify the epidural space. We present a case of pneumocephalus with headache in a parturient following apparently uncomplicated labour epidural analgesia.
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Aire , Analgesia Epidural/efectos adversos , Analgesia Obstétrica/efectos adversos , Cefalea/etiología , Inyecciones Epidurales/efectos adversos , Neumocéfalo/etiología , Adulto , Analgesia Epidural/métodos , Analgesia Obstétrica/métodos , Analgesia Controlada por el Paciente , Parto Obstétrico , Femenino , Humanos , EmbarazoRESUMEN
Sildenafil utilization was prospectively evaluated among 153 men with a history of erectile dysfunction (ED)-prescription drug use prior to starting sildenafil and 164 men who were new starters of ED-prescription drugs. Further, some determinants of sildenafil discontinuation were identified. During a median follow-up period of 18 months 45% of all patients discontinued sildenafil treatment, regardless of earlier treatment history. However, patients with a history of drug treatment for ED were nearly eight times as likely to switch or re-start another ED-prescription drug after discontinuing sildenafil compared to previously untreated users. Age >60 y, diabetes medication, nitrate use, and use of incontinence pads (a proxy for disease/surgery in the pelvic region) were associated with an increased likelihood of discontinuing sildenafil. Although the introduction of sildenafil reduced the barrier to seek medical help for erectile problems, sildenafil treatment failure in previously untreated patients results in a high dropout rate from further ED drug treatment of any kind.
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Prescripciones de Medicamentos/estadística & datos numéricos , Disfunción Eréctil/tratamiento farmacológico , Disfunción Eréctil/epidemiología , Piperazinas/administración & dosificación , Vasodilatadores/administración & dosificación , Anciano , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Países Bajos/epidemiología , Pacientes Desistentes del Tratamiento , Estudios Prospectivos , Purinas , Citrato de Sildenafil , SulfonasRESUMEN
OBJECTIVE: To design and test a revised data collection system for routine patient based data in the Community Hospital setting in Scotland. DESIGN: A two part qualitative study was designed to identify the requirements for Community Hospital information, develop a data set to meet these requirements and pilot a proposed Community Hospital Information System. SETTING: Identification of the information deficit (Stage 1) involved administering face to face questionnaires in all relevant Health Board areas in Scotland; piloting of the proposed information system (Stage 2) was carried out in four Community Hospitals in Scotland. RESULTS: Stage 1 of the study highlighted the information requirements as including: who is being treated; why they are there; how complex their needs are; what is being done and by whom; and what is happening next. The additionally required data included: admission reason--medical/social; type of care--intended and provided; all relevant diagnoses and social factors; medication--on admission and discharge; interventions--nursing/GP/consultant; dependency throughout stay; delayed discharge information; and discharge plan. The summary of recommendations that flowed from this part of the study includes: incremental electronic record; link with GP and acute systems; interface with other community systems; duplication of recording; accessibility at local level with variable levels of access (to protect patient confidentiality). Stage 2 of the study piloted the collection of the proposed dataset and permitted development of suitable feedback information, in particular the patient summary screens. Economic evaluation of the proposed dataset compared to the existing data was carried out in parallel with the study and is reported elsewhere. CONCLUSION: It is feasible and highly desirable to collect clinically useful information at little additional cost and to provide relevant feedback, including useful patient summary screens, representing the patient stay in hospital.
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Recolección de Datos/métodos , Sistemas de Información en Hospital/organización & administración , Hospitales Comunitarios , Humanos , Proyectos Piloto , EscociaRESUMEN
The twin problems of poor compliance and poor persistence with prescribed antihypertensive drug regimens appear to be responsible for much of the huge shortfall in the proportion of hypertensives whose treatment brings their blood pressure down to satisfactory levels. A further problem is the confounding of nonresponse and poor compliance in patients with "drug-resistant hypertension," in that about half of such patients are poor compliers, whose response to simple regimens usually proves satisfactory once their compliance with prescribed regimens is corrected. Electronic means for compiling ambulatory patients' drug dosing histories have now made it both technically and economically feasible to distinguish clearly between noncompliers and nonresponders, which clinical judgment cannot do because it is no better at making this crucial distinction than a coin toss. With the advent of reliable, economical measurements of patient compliance with prescribed drug dosing regimens, we can probably eliminate most of the compliance problems. The problem awaiting us after that is poor persistence with prescribed regimens for antihypertensive and other cardiovascular medicines that are meant for long-term or life-long use. A recent study has shown that median persistence with fully reimbursed drugs of the statin class is only 6 months, which is about one fortieth of the length it should be to realize full benefits of such therapy.
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Antihipertensivos/economía , Hipertensión/economía , Negativa del Paciente al Tratamiento , Antihipertensivos/uso terapéutico , Humanos , Hipertensión/tratamiento farmacológicoRESUMEN
BACKGROUND: In previous research, lapses in dosing of paroxetine or sertraline were associated with significantly more discontinuation symptoms and deterioration of depressive symptomatology compared with fluoxetine. AIMS: To evaluate dosing lapses in patients chronically treated with selective serotonin reuptake inhibitors (SSRIs) in uncontrolled circumstances. METHOD: In a prospective observational study we evaluated compliance data in chronic users of SSRIs using electronic drug exposure monitors. RESULTS: During a 3-month follow-up we found that 50/69 (72.5%) patients missed at least one dosing day and 20/69 (29.0%) missed two or more consecutive days. CONCLUSIONS: About 30% of patients treated with short-acting SSRIs had dosing lapses of 2 or more days, which, as described in prior studies, is long enough to result in clinically relevant deterioration of mental status.
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Trastorno Depresivo/tratamiento farmacológico , Cooperación del Paciente , Inhibidores Selectivos de la Recaptación de Serotonina/administración & dosificación , Adolescente , Adulto , Distribución por Edad , Anciano , Trastornos de Ansiedad/tratamiento farmacológico , Trastornos de Ansiedad/psicología , Enfermedad Crónica , Trastorno Depresivo/psicología , Esquema de Medicación , Monitoreo de Drogas/métodos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Inhibidores Selectivos de la Recaptación de Serotonina/uso terapéuticoRESUMEN
OBJECTIVE: To identify a Dutch cohort of sildenafil users and describe their baseline characteristics. PATIENTS AND METHODS: Each pharmacy in The Netherlands (n = 1571) was asked to identify prospectively the first 20 sildenafil prescriptions in their pharmacy over 1 year, and to complete and return a registration form. The collected data included patient characteristics, the details of the sildenafil prescription (date, prescriber, number of prescriptions, dosing), and the use of co-medication by the patient in the year preceding the sildenafil prescription. RESULTS: Data were collected from 4460 sildenafil prescriptions during the year under study, relating to 3477 individual patients. Most of the cohort had cardiovascular morbidity or diabetes. Sildenafil seems to have been used by a new, previously untreated population of patients with erectile dysfunction. In addition, 69 men were identified who could have been using nitrates and sildenafil concomitantly. CONCLUSION: A cohort of patients using sildenafil was identified and characterized; they appeared to be representative of sildenafil users in The Netherlands. This cohort will be followed prospectively to evaluate the medical status (particularly cardiovascular) of the patients with time.
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Inhibidores de Fosfodiesterasa/uso terapéutico , Piperazinas/uso terapéutico , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Anticoagulantes/uso terapéutico , Antidepresivos/uso terapéutico , Fármacos Cardiovasculares/uso terapéutico , Distribución de Chi-Cuadrado , Estudios de Cohortes , Recolección de Datos , Prescripciones de Medicamentos/estadística & datos numéricos , Quimioterapia Combinada , Disfunción Eréctil/tratamiento farmacológico , Disfunción Eréctil/epidemiología , Fármacos Gastrointestinales/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Países Bajos/epidemiología , Purinas , Citrato de Sildenafil , SulfonasRESUMEN
Concerted work to develop human pharmaceuticals based on rate-controlled drug delivery systems began in 1970. Today there are over three dozen such products, plus a few for veterinary use. In addition, osmotic minipumps have been extensively used since 1978, resulting in over 6000 publications in the pharmacological, endocrinological and physiological literature. Rate-controlled delivery provides for drug entry into the bloodstream continuously at either a constant or a modulated rate. By this means, one avoids the usual peak and trough pattern of drug concentrations in plasma, with its echoing peak and trough pattern of drug actions, during the interval between successive doses. In contrast to the happenstance release kinetics of rapid-release dosage forms, rate-controlled delivery systems can be designed to provide specific temporal patterns of drug concentration in plasma, for the purpose of optimizing the selectivity of drug action, the interval between successive administerings of drug and the likelihood that the next administering will occur at the proper time.