Clinical pharmacokinetics and pharmacogenetics of tamoxifen and endoxifen

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.     

临床药师在导管接触性溶栓联合抗凝治疗急性下肢深静脉血栓的用药分析与药学监护中的作用

目的 探讨临床药师在急性下肢深静脉血栓患者个体化治疗中的作用。 方法 对南京鼓楼医院血管外科2018年8月收治的8例急性下肢深静脉血栓患者的治疗过程进行分析，结合临床药学知识制定导管接触性溶栓及抗凝用药方案，对患者实施全程药学监护。 结果 溶栓治疗期间，患者血浆纤维蛋白原水平呈明显下降趋势，血浆D-二聚体水平呈先升高后降低的趋势，血小板未见明显下降趋势；8例患者在溶栓治疗过程中，2例出现轻微牙龈出血后自行止血，1例出现血尿，停止溶栓治疗后改为口服抗凝药，血尿现象消失。患者预后改善明显，血栓完全溶解，静脉恢复畅通，用药安全得到有效保障。 结论 临床药师在导管接触性溶栓联合抗凝治疗急性下肢深静脉血栓患者的个体化用药监护方面发挥了积极作用。     

Development of a Pilates Teaching Framework from an international survey of teacher practice

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.     

Daratumumab,Bortezomib, and Dexamethasone Versus Bortezomib and Dexamethasone in Patients With Previously Treated Multiple Myeloma: Three-year Follow-up of CASTOR

BackgroundIn the phase III CASTOR study in relapsed or refractory multiple myeloma, daratumumab, bortezomib, and dexamethasone (D-Vd) demonstrated significant clinical benefit versus Vd alone. Outcomes after 40.0 months of median follow-up are discussed.Patients and MethodsEligible patients had received ≥ 1 line of treatment and were administered bortezomib (1.3 mg/m²) and dexamethasone (20 mg) for 8 cycles with or without daratumumab (16 mg/kg) until disease progression.ResultsOf 498 patients in the intent-to-treat (ITT) population (D-Vd, n = 251; Vd, n = 247), 47% had 1 prior line of treatment (1PL; D-Vd, n = 122; Vd, n = 113). Median progression-free survival (PFS) was significantly prolonged with D-Vd versus Vd in the ITT population (16.7 vs. 7.1 months; hazard ratio [HR], 0.31; 95% confidence interval [CI], 0.25-0.40; P < .0001) and the 1PL subgroup (27.0 vs. 7.9 months; HR, 0.22; 95% CI, 0.15-0.32; P < .0001). In lenalidomide-refractory patients, the median PFS was 7.8 versus 4.9 months (HR, 0.44; 95% CI, 0.28-0.68; P = .0002) for D-Vd (n = 60) versus Vd (n = 81). Minimal residual disease (MRD)–negativity rates (10⁻⁵) were greater with D-Vd versus Vd (ITT: 14% vs. 2%; 1PL: 20% vs. 3%; both P < .0001). PFS2 was significantly prolonged with D-Vd versus Vd (ITT: HR, 0.48; 95% CI, 0.38-0.61; 1PL: HR, 0.35; 95% CI, 0.24-0.51; P < .0001). No new safety concerns were observed.ConclusionAfter 3 years, D-Vd maintained significant benefits in patients with relapsed or refractory multiple myeloma with a consistent safety profile. D-Vd provided the greatest benefit at first relapse and increased MRD-negativity rates.     

A Reminder of Methylene Blue's Effectiveness in Treating Vasoplegic Syndrome after On-Pump Cardiac Surgery

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.