Introduction: Tamoxifen dominates the anti-estrogenic therapy in the early and metastatic breast cancer setting. Tamoxifen has a complex metabolism, being mainly metabolized by CYP2D6 into its 30–100 times more potent metabolite, endoxifen. Recently, a phase I study in which endoxifen as an orally z-endoxifen hydrochloride has been successfully evaluated.
Areas covered: the principal pharmacogenetic and non-genetic differences in the pharmacology of tamoxifen and endoxifen are evaluated. To this end, references from PubMed, Embase or Web of Science, among others, were reviewed As non-genetic factors, important differences and similarities such age, or adherence to tamoxifen therapy are comprehensively illustrated. Additionally, since CYP2D6 genotypes are considered the main limitation of tamoxifen, many studies have investigated the association between the worsened clinical outcomes in patients with non-functional CYP2D6 genotypes. In this review, an overview of the research on this field is presented. Also, a summary describing the literature about individualizing tamoxifen therapy with endoxifen concentrations and its limitations is listed.
Expert opinion: z-endoxifen hydrochloride is only investigated in the metastatic setting, still more research is required before its place in therapeutics is known. Similarly, monitoring tamoxifen efficacy based on endoxifen concentrations might not be overall recommended due to the limited evidence available. 相似文献
The purpose of this study was to elucidate the involvement of Mate1 in the tubular secretion of trimethoprim and saturation of Mate1-mediated efflux to address the mechanisms underlying the pharmacokinetic drug interactions with trimethoprim. Trimethoprim is a more potent inhibitor of MATE2-K than MATE1 with Ki values (μM) of 0.030–0.28 and 2.4–5.9, respectively. Trimethoprim is a substrate of human MATE1 and MATE2-K with Km values of 2.3 ± 0.9 and 0.018 ± 0.004 μM, and mouse Mate1, but not human OCT2, mouse Oct1 and Oct2. Pyrimethamine significantly reduced the renal clearance (CLR) of trimethoprim (mL/min/kg) from 40.0 ± 5.1 to 20.1 ± 3.7 (p < 0.05). Trimethoprim was given to mice at three infusion rates (150, 500, and 1500 nmol/min/kg). Together with an increase in the plasma concentrations of trimethoprim, the CLR (mL/min/kg) of trimethoprim decreased to 25.9 ± 3.2, 13.5 ± 5.7, and 8.92 ± 1.50 at the respective rates. Trimethoprim decreased the CLR of rhodamine 123 in an infusion rate-dependent manner: 11.5 ± 1.3 (control), 5.17 ± 1.55, 1.31 ± 0.50, and 0.532 ± 0.180. These results suggest that Mate1 mediates the tubular secretion of trimethoprim, and at therapeutic doses, MATEs-mediated efflux can be saturated, and thereby, cause drug interactions with other MATE substrates. 相似文献
Introduction: There are at the minimum two major, quite different approaches to advance drug discovery. The first being the target-based drug discovery (TBDD) approach that is commonly referred to as the molecular approach. The second approach is the phenotype-based drug discovery (PBDD), also known as physiology-based drug discovery or empirical approach.
Area covered: The authors discuss, herein, the need for developing radiation countermeasure agents for various sub-syndromes of acute radiation syndromes (ARS) following TBDD and PBDD approaches. With time and continuous advances in radiation countermeasure drug development research, the expectation is to have multiple radiation countermeasure agents for each sub-syndrome made available to radiation exposed victims.
Expert opinion: The majority of the countermeasures currently being developed for ARS employ the PBDD approach, while the TBDD approach is clearly under-utilized. In the future, an improved drug development strategy might be a ‘hybrid’ strategy that is more reliant on TBDD for the initial drug discovery via large-scale screening of potential candidate agents, while utilizing PBDD for secondary screening of those candidates, followed by tertiary analytics phase in order to pinpoint efficacious candidates that target the specific sub-syndromes of ARS. 相似文献
ObjectiveTo propose the Intense Pulsed Light (IPL) therapy as a helpful supplementary treatment in patients with dry eye disease.Material and methodsRetrospective cross sectional design. Medical records of patients in whom dry eye disease symptoms were not satisfactorily controlled with medical therapy alone and who underwent additional IPL with at least three sessions completed. Data were analyzed before therapy and 3 weeks after its completion to asses improvement. Determination of symptoms, through a visual analog scale; tear film stability, through tear Break Up Time (tBUT); measurement of tear secretion, through Schirmer Test; and ocular surface staining with Van Bijsterveld score were evaluated. SPSS software and nonparametric analysis of repeated measures were used. The study was approved by the ethics committee.Results50 eyes from 25 subjects were reviewed. There were 9 males (36%) and 16 females (64%), with a median age of 59 years (IQR 52-64). The median of the symptoms scale was 8 (IQR 8-9) and 3 (IQR 2-4) before and after the therapy respectively (P < .05). The median of BUT was 4 (IQR 3-5) and 10 (IQR 8-11), Schirmer test was 13 (IQR 12-15) and 15 (IQR 13-20), and Van Bijsterveld score was 3 (RIC 3-4) and 2 (IQR 2-3) before and after the therapy respectively (P < .05, for all measurements).ConclusionIPL treatment has excellent results regarding both: dry eye disease symptoms improvement and in office objective tests such as tBUT, Schirmer test and Van Bijsterveld score; IPL could be considered as an effective adjunct for dry eye disease. 相似文献
ObjectivePilates is used increasingly in a variety of clinical settings. However, there is lack of clarity in the literature as to what is meant by the term. Teachers incorporating apparatus based on the designs of Joseph Pilates (1883–1967) into their practice refer to themselves as Comprehensive Teachers, and this group divides itself further into Classical and Contemporary practice. The aim of this research was to explore the meanings of these terms with Comprehensive Teachers and to develop a framework that reflects current views and practice.MethodOnline international survey of Pilates Teachers through closed Facebook forums. Open questions were used to elicit views of the definition and practice of Pilates, and how standards should be set across the sector.ResultsOf 109 participants, 35% were based in the UK and 32% in the USA; 48% identified as Classical teachers, 32% as Contemporary, 5% as both and 15% as Matwork instructors. A thematic analysis of the qualitative data revealed agreement on the scope and content of Classical and Contemporary Comprehensive Pilates, however the discourse indicated there might be stereotyping about each other's practice. Classical teachers, for example, spoke of their own practice as authentic while Contemporary teachers used terms such as strict and inflexible for Classical practice. However, members of either group may incorporate both Classical and Contemporary approaches within their practice. We have designed a Pilates Teaching Framework to take into account the types of apparatus, the types of exercises and the order in which the exercises are executed.ConclusionsA framework that emphasises Pilates teaching rather than teacher practice is proposed for consistency and clarity when describing Pilates in professional and public contexts. 相似文献
The inflammatory response induced by cardiopulmonary bypass decreases vascular tone, which in turn can lead to vasoplegic syndrome. Indeed the hypotension consequent to on-pump cardiac surgery often necessitates vasopressor and intravenous fluid support. Methylene blue counteracts vasoplegic syndrome by inhibiting the formation of nitric oxide.We report the use of methylene blue in a 75-year-old man who developed vasoplegic syndrome after cardiac surgery. After the administration of methylene blue, his hypotension improved to the extent that he could be weaned from vasopressors. The use of methylene blue should be considered in patients who develop hypotension refractory to standard treatment after cardiac surgery. 相似文献
ABSTRACT Most senior veterans who live in veteran homes in Taiwan have few interpersonal relationships. Aging is often accompanied by solitude and illness, which causes senior veterans to doubt the meaning of life and to lose confidence in the value of life. This study tested the effectiveness of a group reminiscence therapy protocol on the depression and meaning of life among elderly institutionalized veterans. A quasi-experimental design was applied. A convenience sample of older adults was drawn from two veteran homes in southern Taiwan. Participants were assigned to intervention or control groups based on the veterans' homes they attended. The participants in the intervention group carried out group reminiscence therapy for 8 weeks in addition to their daily activities. The participants in the comparison group maintained their daily activities. Both groups were evaluated using the GDS-SF and MLS scale including two aspects of depression mood and meaning of life in weeks 1 and 8. The overall life satisfaction increased significantly over time for the intervention group compared to the comparison group from week 1 to week 8. The group reminiscence therapy programs showed promising effects in improving the depression and meaning of life of older veterans living in veteran homes. 相似文献