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1.
Br J Clin Pharmacol ; 88(3): 1223-1234, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34449087

RESUMO

AIMS: The prevalence of vitamin D deficiency is high in children with chronic kidney disease (CKD). However, current dosing recommendations are based on limited pharmacokinetic (PK) data. This study aimed to develop a population PK model of colecalciferol that can be used to optimise colecalciferol dosing in this population. METHODS: Data from 83 children with CKD were used to develop a population PK model using a nonlinear mixed effects modelling approach. Serum creatinine and type of kidney disease (glomerular vs. nonglomerular disease) were investigated as covariates, and optimal dosing was determined based on achieving and maintaining 25-hydroxyvitamin D (25(OH)D) concentration of 30-48 ng/mL. RESULTS: The time course of 25(OH)D concentrations was best described by a 1-compartment model with the addition of a basal concentration parameter to reflect endogenous 25(OH)D production from diet and sun exposure. Colecalciferol showed wide between-subject variability in its PK, with total body weight scaled allometrically the only covariate included in the model. Model-based simulations showed that current dosing recommendations for colecalciferol can be optimised using a weight-based dosing strategy. CONCLUSION: This is the first study to describe the population PK of colecalciferol in children with CKD. PK model informed dosing is expected to improve the attainment of target 25(OH)D concentrations, while minimising the risk of overdosing.


Assuntos
Insuficiência Renal Crônica , Deficiência de Vitamina D , Criança , Feminino , Humanos , Masculino , Insuficiência Renal Crônica/complicações , Deficiência de Vitamina D/tratamento farmacológico
2.
Br J Clin Pharmacol ; 87(3): 1338-1346, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32803772

RESUMO

AIM: To evaluate the type (licensed vs unlicensed) and cost of preparations used to fulfil vitamin D prescriptions in England over time, and to compare measured vitamin D content of selected vitamin D preparations against labelled claim. METHODS: Retrospective analysis of vitamin D prescription data in primary care in England (2008-2018). Laboratory analysis of 13 selected vitamin D preparations. RESULTS: Alongside a rise in the number of oral licensed colecalciferol preparations from 0 to 27 between 2012 and 2018, the proportion of vitamin D prescriptions in which licensed vitamin D preparations were supplied increased from 11.8 to 54.2%. However, the use of unlicensed food supplements (dose strength 400-50 000 IU) remained high, accounting for 39.7% of vitamin D prescriptions in 2018. The two licensed preparations showed mean (±SD) vitamin D content of 90.9 ± 0.7% and 90.5 ± 3.9% of the labelled claimed amount, meeting the British Pharmacopeia specification for licensed medicines (90-125% of labelled claim). The 11 food supplements showed vitamin D content ranging from 41.2 ± 10.6% to 165.3 ± 17.8% of the labelled claim, with eight of the preparations failing to comply with the food supplement specification (80-150% of labelled claim). CONCLUSIONS: Despite the increasing availability of quality assured licensed preparations, food supplements continued to be used interchangeably with licensed preparations to fulfil vitamin D prescriptions. Food supplements, manufactured under less stringent quality standards, showed wide variations between measured and declared vitamin D content, which could lead to the risk of under- and over-dosing.


Assuntos
Laboratórios , Vitamina D , Prescrições de Medicamentos , Inglaterra , Humanos , Atenção Primária à Saúde , Estudos Retrospectivos
3.
Br J Haematol ; 184(6): 912-924, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30697708

RESUMO

The availability of direct oral anticoagulants (DOACs) has led to a paradigm shift in the field of anticoagulation, with DOACs increasingly being prescribed for patients in preference to vitamin K antagonists and low molecular weight heparin. Despite good experience with the use of these agents at fixed doses, there are clinical scenarios where monitoring is recommended. Data from phase III studies of the DOACs and small real-world studies suggest a relationship between DOAC concentration and clinical events. The DOACs have differing impacts on the common tests of haemostasis and it is important that clinicians are familiar with the sensitivity of the reagents used in their laboratory to individual DOACs. The specific DOAC drug concentrations can be assayed in the laboratory, when required, to guide appropriate clinical decision-making. Studies from the real world with sufficient numbers evaluating the association of DOAC concentrations with outcomes should be a research priority in order to understand if we could do better through dose individualisation.


Assuntos
Anticoagulantes/uso terapêutico , Coagulação Sanguínea/efeitos dos fármacos , Monitoramento de Medicamentos/métodos , Anticoagulantes/farmacologia , Humanos
4.
J Thromb Thrombolysis ; 48(2): 315-322, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31168688

RESUMO

Routine thromboprophylaxis (TP) in newly-diagnosed multiple myeloma (NDMM) patients comprises either aspirin for standard risk patients or low molecular weight heparin for high risk patients. Studies using DOACs in cancer patients include few with myeloma. The aim of this feasibility clinical trial was to establish the foundations for creating a multicentre trial and identify any safety concerns with apixaban. Patient perspectives were sought. NDMM patients were stratified according to VTE risk and randomised to either standard TP or apixaban 2.5 mg BD and reviewed every 3 weeks throughout their chemotherapy. Two focus groups were carried out on 2 occasions at King's College Hospital and Guy's Hospital, London. Each lasted an hour, were recorded, transcribed and themes explored using NVivo 11. Ten patients were recruited, 2 considered high risk and received apixaban and 8 standard risk; 4 randomised to aspirin and 4 to apixaban. Five patients and 2 carers participated in the focus groups. There were no major bleeding or VTE events. Patients were not aware of the thrombotic risk associated with cancer. There is a lack of both written and verbal information on this topic. Myeloma patients were happy to be included in more than one trial simultaneously. Our study provides information on the difficulties facing physicians and patients on obtaining evidence of the safety of DOACs in the context of myeloma. Despite patients being happy to co-recruit into thromboprophylaxis trials along with chemotherapy trials this is not current practice.EudraCT Number: 2015-002668-18.


Assuntos
Mieloma Múltiplo/complicações , Ensaios Clínicos Controlados Aleatórios como Assunto , Tromboembolia Venosa/prevenção & controle , Idoso , Aspirina/uso terapêutico , Protocolos de Ensaio Clínico como Assunto , Estudos de Viabilidade , Feminino , Grupos Focais , Heparina de Baixo Peso Molecular/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Pirazóis/uso terapêutico , Piridonas/uso terapêutico , Medição de Risco , Tromboembolia Venosa/etiologia
5.
Br J Haematol ; 183(3): 346-363, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30334572

RESUMO

The prevention and treatment of venous thromboembolism (VTE) poses distinct gender-specific challenges. Women of childbearing age are at an increased risk of VTE secondary to the transient risk factors of combined hormonal contraception (CHC) and pregnancy. Cancers specific to women are associated with a significant burden of VTE; whilst the incidence of VTE in localised breast cancer is 5 per 1000 person-years, more cases are seen due to the prevalence of breast cancer. Treatment of VTE in women can be complicated by abnormal uterine bleeding, now increasingly reported with direct oral anticoagulants (DOACs) as well as vitamin K antagonists. Divergence between international guidelines regarding the use of CHC following an oestrogen-associated VTE and appropriate withdrawal of such contraception requires clarification for clinicians. Additionally, there is uncertainty as to whether to consider such events provoked or unprovoked and, consequently, the optimal duration of treatment in these women remains unclear. During pregnancy and the puerperium, the traditional anticoagulants remain the agents of choice with no further advances in DOAC safety data, and similarly in lactation. Further studies evaluating the safety and optimal treatment strategies in these women are awaited.


Assuntos
Neoplasias , Complicações Cardiovasculares na Gravidez , Complicações Neoplásicas na Gravidez , Tromboembolia Venosa , Saúde da Mulher , Anticoncepcionais Orais Hormonais/efeitos adversos , Anticoncepcionais Orais Hormonais/uso terapêutico , Feminino , Humanos , Neoplasias/metabolismo , Neoplasias/patologia , Neoplasias/prevenção & controle , Gravidez , Complicações Cardiovasculares na Gravidez/metabolismo , Complicações Cardiovasculares na Gravidez/patologia , Complicações Cardiovasculares na Gravidez/prevenção & controle , Complicações Neoplásicas na Gravidez/metabolismo , Complicações Neoplásicas na Gravidez/patologia , Complicações Neoplásicas na Gravidez/prevenção & controle , Tromboembolia Venosa/metabolismo , Tromboembolia Venosa/patologia , Tromboembolia Venosa/prevenção & controle
6.
Des Monomers Polym ; 21(1): 9-17, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29491828

RESUMO

Epoxy resin of 9,9'-bis-(3,5-dibromo-4-hydroxyphenyl) anthrone-10 (EANBr, EEW 490) was synthesized and was characterized by IR and 1HNMR . EANBr and EPK3251 cured resin (EANBrC) were characterized by DSC and TGA at 10°Cmin-1 under nitrogen atmosphere. Broad DSC endothermic transitions of EANBr (265.3 °C) and EANBrC (291.4 °C) are due to some physical change and further confirmed by no weight loss in their TG thermograms. EANBr and EANBrC are thermally stable up to 340 °C and 310 °C, respectively. EANBr has followed single step degradation kinetics, while EANBrC has followed two step degradation kinetics. EANBr followed apparently zero order kinetics, while EANBrC followed apparently second order (1.80) and first order (0.89) degradation kinetics, respectively. Ea and A values of EANBrC (299.7 kJmol-1 and 6.32 × 1020 s-1) were found higher than that of EANBr (201 kJmol-1 and 2.45 × 1013 s-1) due to more rigid nature of EANBrC. The ΔS* value of the first step degradation of EANBrC (146.3 JK-1 mol-1) was found much more than that of EANBr (4.6 JK-1 mol-1). Jute - EANBr composite (J-EANBr) was prepared by compression molding technique at 120 °C for 5 h and under 20 Bar pressure. The observed tensile strength, flexural strength, electric strength and volume resistivity of J-EANBr are 24.7 MPa, 19.0 MPa, 1.8 kVmm-1 and 3.5 × 1012 ohm cm, respectively. Water absorption in J-EANBr was carried out at 30 ± 2 °C against distilled water, 10% NaCl, 10% HCl, 10% HNO3, 10% H2SO4, 10% NaOH, and 10% KOH and also in boiling water. The equilibrium time and equilibrium water content for J-EANBr in different environments are 384-432 h; 12.7-15.2%, respectively. The observed equilibrium water content and diffusivity trends of J-EANBr are KOH>H2SO4>HCl>NaOH>H2O>NaCl and H2O>NaCl>NaOH>H2SO4>HCl>KOH, respectively. Good thermo-mechanical, electrical properties and excellent hydrolytic stability of J-EANBr may be useful for high temperature applications in diverse fields.

7.
Br J Haematol ; 178(6): 838-851, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28573648

RESUMO

The choice for oral anticoagulant (OAC) therapy was previously limited to the vitamin K antagonists (VKAs). The advent of the direct oral anticoagulants (DOACs) brought with it the expectation that oral anticoagulation would become simpler (with the elimination of routine monitoring and introduction of a fixed-dose anticoagulant), and that the use of VKAs would be slowly phased out. Although DOACs have made anticoagulation more convenient and accessible, we are now faced with what can be described as a tyranny of choice, together with many unanswered questions relating to DOAC use. These include optimal DOAC selection and dosing, use in complex 'real-world' patients, the role for monitoring and issues surrounding adherence. Warfarin remains the anticoagulant of choice in certain scenarios (e.g. metallic heart valves). The future holds much excitement: clinical studies are underway to expand the indications for DOACs and experience continues to grow outside the trials setting.


Assuntos
Anticoagulantes/administração & dosagem , Tromboembolia Venosa/prevenção & controle , Administração Oral , Anticoagulantes/efeitos adversos , Anticoagulantes/uso terapêutico , Peso Corporal , Relação Dose-Resposta a Droga , Esquema de Medicação , Monitoramento de Medicamentos/métodos , Hemorragia Gastrointestinal/induzido quimicamente , Humanos , Adesão à Medicação , Vitamina K/antagonistas & inibidores , Varfarina/administração & dosagem , Varfarina/efeitos adversos , Varfarina/uso terapêutico , Saúde da Mulher
9.
Circulation ; 132(3): 194-204, 2015 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-25995317

RESUMO

BACKGROUND: Evidence regarding the use of direct oral anticoagulants (DOACs) in the elderly, particularly bleeding risks, is unclear despite the presence of greater comorbidities, polypharmacy, and altered pharmacokinetics in this age group. METHODS AND RESULTS: We performed a systematic review and meta-analysis of randomized trials of DOACs (dabigatran, apixaban, rivaroxaban, and edoxaban) for efficacy and bleeding outcomes in comparison with vitamin K antagonists (VKA) in elderly participants (aged ≥75 years) treated for acute venous thromboembolism or stroke prevention in atrial fibrillation. Nineteen studies were eligible for inclusion, but only 11 reported data specifically for elderly participants. The efficacy in managing thrombotic risks for each DOAC was similar or superior to VKA in elderly patients. A nonsignificantly higher risk of major bleeding than with VKA was observed with dabigatran 150 mg (odds ratio, 1.18; 95% confidence interval, 0.97-1.44) but not with the 110-mg dose. Significantly higher gastrointestinal bleeding risks with dabigatran 150 mg (1.78, 1.35-2.35) and dabigatran 110 mg (1.40, 1.04-1.90) and lower intracranial bleeding risks than VKA for dabigatran 150 mg (0.43, 0.26-0.72) and dabigatran 110 mg (0.36, 0.22-0.61) were also observed. A significantly lower major bleeding risk in comparison with VKA was observed for apixaban (0.63, 0.51-0.77), edoxaban 60 mg (0.81, 0.67-0.98), and 30 mg (0.46, 0.38-0.57), whereas rivaroxaban showed similar risks. CONCLUSIONS: DOACs demonstrated at least equal efficacy to VKA in managing thrombotic risks in the elderly, but bleeding patterns were distinct. In particular, dabigatran was associated with a higher risk of gastrointestinal bleeding than VKA. Insufficient published data for apixaban, edoxaban, and rivaroxaban indicate that further work is needed to clarify the bleeding risks of these DOACs in the elderly. SYSTEMATIC REVIEW REGISTRATION: http://www.crd.york.ac.uk/PROSPERO. Unique identifier: PROSPERO CRD42014007171/.


Assuntos
Anticoagulantes/administração & dosagem , Anticoagulantes/efeitos adversos , Fibrilação Atrial/tratamento farmacológico , Prevenção Secundária/métodos , Acidente Vascular Cerebral/prevenção & controle , Tromboembolia Venosa/prevenção & controle , Administração Oral , Idoso , Fibrilação Atrial/diagnóstico , Hemorragia/induzido quimicamente , Hemorragia/diagnóstico , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Acidente Vascular Cerebral/diagnóstico , Tromboembolia Venosa/diagnóstico
10.
Br J Haematol ; 174(1): 30-42, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27173746

RESUMO

Adherence to medication, commonly reported as being 50% in chronic diseases, is of great concern in healthcare. Medication non-adherence is particularly apparent in chronic diseases, where treatment is often preventative and may provide little or no symptomatic relief or feedback for the patient. A lot of research has been undertaken to describe the extent of non-adherence to long-term anticoagulation therapy, particularly with vitamin K antagonists and more recently with direct oral anticoagulants. However, the literature is scarce with respect to describing adherence to anticoagulation in terms of the behavioural aspects that influence medicine use. Utilizing the COM-B (capability, opportunity, motivation and behaviour) psychological model of non-adherence, we present the available evidence, not only in terms of describing the extent of the non-adherence problem, but also describing why patients do not adhere, offering theory-driven and evidence-based solutions to improve long-term adherence to chronic anticoagulation therapy. Lessons learned are not only applicable within the field of anticoagulation but throughout haematology.


Assuntos
Anticoagulantes/uso terapêutico , Adesão à Medicação/psicologia , Humanos , Assistência de Longa Duração , Modelos Psicológicos
11.
Circulation ; 128(13): 1462-9, 2013 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-23940396

RESUMO

BACKGROUND: The optimal dosing strategy of low-molecular-weight heparins for the treatment of antenatal venous thromboembolism is not known. The physiological changes associated with pregnancy alter the pharmacokinetic profile of low-molecular-weight heparins, which has led to controversy and subsequent variation in practice, when pregnant women with venous thromboembolism are treated with low-molecular-weight heparins. Our objective was to develop a robust pharmacokinetic model of enoxaparin during the antenatal period to address this problem. METHOD AND RESULTS: Women prescribed antenatal enoxaparin were eligible to enroll in the study. Recruited women were reviewed monthly and had up to 3 anti-Xa activities (trough and 1 and 3 hours after dose) drawn at each clinic attendance. Compartmental pharmacokinetic modeling was conducted using nonlinear mixed-effects modeling. One hundred twenty-three patients contributed 795 anti-Xa activities for pharmacokinetic modeling purposes. Both enoxaparin clearance and volume of distribution were increased during pregnancy. Simulations of once- versus twice-daily enoxaparin administration demonstrated that both dosing regimens would reach target 3-hour plasma concentrations throughout the duration of the pregnancy. When trough anti-Xa activity was simulated, both once- and twice-daily regimens exhibited an increase in trough anti-Xa activity with the progression of pregnancy. This is explained by the significant increase in volume of distribution observed during pregnancy. CONCLUSIONS: The half-life of enoxaparin is prolonged with the progression of pregnancy, and our work provides compelling evidence for prescribing once-daily enoxaparin for the treatment of antenatal venous thromboembolism. National and international guideline recommendations should be reconsidered.


Assuntos
Anticoagulantes/farmacologia , Enoxaparina/farmacologia , Gravidez/sangue , Cuidado Pré-Natal/métodos , Relação Dose-Resposta a Droga , Feminino , Humanos , Gravidez/efeitos dos fármacos , Tromboembolia Venosa/sangue , Tromboembolia Venosa/prevenção & controle
12.
Br J Haematol ; 164(5): 619-29, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24224681

RESUMO

For patients prescribed chronic vitamin K antagonist therapy requiring a surgical or invasive procedure, the question of whether or not to bridge and how to bridge is commonly encountered in clinical practice. Bridging anticoagulation has evolved over the years and the evidence base for current practice is deficient in many areas. Clinical trials currently being completed with conventional anticoagulants should help strengthen the evidence base for future practice. The availability of novel oral anticoagulants is a welcome addition, though their optimal management peri-procedure is yet to be determined. Prospective multi-centre controlled studies that can provide the evidence base for novel oral anticoagulant peri-procedural management are required.


Assuntos
Anticoagulantes/uso terapêutico , Administração Oral , Anticoagulantes/administração & dosagem , Anticoagulantes/efeitos adversos , Esquema de Medicação , Medicina Baseada em Evidências/métodos , Hemorragia/induzido quimicamente , Heparina de Baixo Peso Molecular/administração & dosagem , Heparina de Baixo Peso Molecular/efeitos adversos , Heparina de Baixo Peso Molecular/uso terapêutico , Humanos , Assistência Perioperatória/métodos , Medição de Risco/métodos , Tromboembolia/etiologia , Vitamina K/antagonistas & inibidores
14.
Ther Drug Monit ; 36(5): 597-605, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24695356

RESUMO

BACKGROUND: Direct oral anticoagulants (DOACs) are prescribed for systemic anticoagulation. Fixed doses are recommended, but dose individualization may be warranted. Functional coagulation assays may be available, but their use requires knowledge of the drug taken. To provide alternative methodology for guiding dosage, we have developed and validated a liquid chromatography-mass spectrometric assay for apixaban, dabigatran, edoxaban, and rivaroxaban at the concentrations attained during therapy. METHODS: Samples, calibrators, and internal quality controls (100 µL) were mixed with internal standard solution (50 µg/L both dabigatran-13C6 and rivaroxaban-13C6 in acetonitrile) and, after centrifugation (16,400g, 4 minutes), supernatant (100 µL) was injected onto a Cyclone-C18-P-XL TurboFlow column. Analytes were focused onto an Accucore PhenylHexyl (2.1 × 100 mm, 2.6 µm) analytical column and eluted using a methanol + acetonitrile (1 + 1):aqueous ammonium acetate (10 mmol/L) gradient. Data were acquired using high-resolution mass spectrometry in full-scan mode (100-2000 m/z) with data-dependent fragmentation to confirm peak identity. Calibration was linear (1-500 µg/L all analytes). RESULTS: Total analysis time was 6 minutes. Intra-assay imprecision (% RSD) at 1 µg/L was 2.6%, 4.2%, 17.3%, and 9.5% for apixaban, dabigatran, edoxaban, and rivaroxaban, respectively. Mean recovery was 96%-101%. No signal suppression or enhancement was observed. Apixaban, dabigatran, and rivaroxaban were stable over 3 freeze-thaw cycles, after storage at room temperature, and at 2-8°C for up to 2 weeks. Edoxaban was stable over 3 freeze-thaw cycles but showed a mean deterioration of 16% if stored at 2-8°C (2 weeks) and of 18% and 70% (1 day and 2 weeks, respectively) at room temperature. CONCLUSIONS: The method is suitable for high-throughput therapeutic drug monitoring of DOACs. The acquisition of full scan data allows for the retrospective identification of metabolites. The method can be used to identify a particular DOAC if information on the drug taken is lacking.


Assuntos
Anticoagulantes/sangue , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Anticoagulantes/química , Benzimidazóis/sangue , Benzimidazóis/química , Dabigatrana , Humanos , Estrutura Molecular , Morfolinas/sangue , Morfolinas/química , Pirazóis/sangue , Pirazóis/química , Piridinas/sangue , Piridinas/química , Piridonas/sangue , Piridonas/química , Rivaroxabana , Tiazóis/sangue , Tiazóis/química , Tiofenos/sangue , Tiofenos/química , beta-Alanina/análogos & derivados , beta-Alanina/sangue , beta-Alanina/química
15.
BMC Pregnancy Childbirth ; 14: 384, 2014 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-25406658

RESUMO

BACKGROUND: It is well accepted that the gravid state is hypercoagulable and a significant cause of both maternal morbidity and mortality in the Western world. Although thrombin generation is reported to be increased in pregnant women, uncertainty exists on the pattern of thrombin generation change during this time. The aim of this study is to describe thrombin generation changes and D-dimer concentrations in women injecting enoxaparin during pregnancy the postnatal period. METHODS: One hundred and twenty-three women injecting enoxaparin had their thrombin generation, as measured by Calibrated Automated Thombinography (CAT), repeatedly assayed during pregnancy, once in each trimester, at delivery and 8 weeks post-partum. Furthermore, to understand the impact enoxaparin has on D-dimer concentrations during pregnancy, D-dimer concentrations were measured monthly in the recruited women. RESULTS: Thrombin generation was found to increase in the first trimester (mean endogenous thrombin potential (ETP): 1391 nmol/L.min), further increasing during the second trimester (mean ETP: 1757 nmol/L.min), after which it plateaued through to delivery, where it peaked (mean ETP: 1857 nmol/L.min) and then fell back at 8 weeks post-partum (ETP: 1293 nmol/L.min). In contrast D-dimer concentrations increased exponentially during the antenatal period, despite the enoxaparin prescription. CONCLUSION: Our results provide further evidence on alterations of thrombin generation during pregnancy and the postnatal period.


Assuntos
Anticoagulantes/administração & dosagem , Enoxaparina/administração & dosagem , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Complicações Cardiovasculares na Gravidez/prevenção & controle , Trombina/biossíntese , Tromboembolia Venosa/prevenção & controle , Adolescente , Adulto , População Negra , Região do Caribe/etnologia , Feminino , Humanos , Pessoa de Meia-Idade , Período Pós-Parto , Gravidez , Complicações Cardiovasculares na Gravidez/tratamento farmacológico , Primeiro Trimestre da Gravidez/sangue , Segundo Trimestre da Gravidez/sangue , Terceiro Trimestre da Gravidez/sangue , Cuidado Pré-Natal , Tromboembolia Venosa/tratamento farmacológico , População Branca , Adulto Jovem
16.
Thromb Res ; 242: 109118, 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39180817

RESUMO

BACKGROUND: Clinical evidence surrounding edoxaban use in patients weighing <50 kg and >120 kg is lacking. The International Society of Thrombosis and Haemostasis Scientific and Standardisation Committee suggests avoiding edoxaban in patients >120 kg. Additionally, concerns exist regarding decreased efficacy in patients prescribed edoxaban for atrial fibrillation with a creatinine clearance (CrCl) >95 ml/min, a finding of the ENGAGE AF-TIMI 48 trial when edoxaban was compared to warfarin. OBJECTIVE: To derive a population pharmacokinetic (PopPK) model using clinical practice data, to understand the impact of bodyweight and renal function on edoxaban pharmacokinetics. METHOD: Edoxaban plasma concentrations and patient characteristics were collated from King's College Hospital anticoagulation clinics between 11/2016 and 08/2022. A PopPK model was developed using non-linear mixed effects modelling and used to simulate edoxaban concentrations at the extremes of bodyweight and with varying renal function. RESULTS: Data from 409 patients (46 < 50 kg, 34 > 120 kg and 123 with a CrCl > 95 ml/min) provided 455 edoxaban plasma concentrations. A one-compartment model with between-subject variability on clearance with a proportional error model best described the data. The most significant covariates impacting on edoxaban exposure were CrCl and bodyweight. Our work suggests that edoxaban exposure in patients weighing up to 140 kg is comparable to those weighing 75 kg. Edoxaban exposure is reduced in patients weighing <50 kg due to the recommended dose reductions. There is also a reduction in AUCss when CrCl > 95 ml/min compared to CrCl 80 ml/min. CONCLUSIONS: Our population PK model for edoxaban suggests that renal function is a key driver for overall edoxaban exposure. Further clinical outcome data is required to understand clinical effectiveness and adverse outcomes.

17.
Res Pract Thromb Haemost ; 8(5): 102468, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39139554

RESUMO

Background: Optimal secondary prevention antithrombotic therapy for patients with antiphospholipid syndrome (APS)-associated ischemic stroke, transient ischemic attack, or other ischemic brain injury is undefined. The standard of care, warfarin or other vitamin K antagonists at standard or high intensity (international normalized ratio (INR) target range 2.0-3.0/3.0-4.0, respectively), has well-recognized limitations. Direct oral anticoagulants have several advantages over warfarin, and the potential role of high-dose direct oral anticoagulants vs high-intensity warfarin in this setting merits investigation. Objectives: The Rivaroxaban for Stroke patients with APS trial (RISAPS) seeks to determine whether high-dose rivaroxaban could represent a safe and effective alternative to high-intensity warfarin in adult patients with APS and previous ischemic stroke, transient ischemic attack, or other ischemic brain manifestations. Methods: This phase IIb prospective, randomized, controlled, noninferiority, open-label, proof-of-principle trial compares rivaroxaban 15 mg twice daily vs warfarin, target INR range 3.0-4.0. The sample size target is 40 participants. Triple antiphospholipid antibody-positive patients are excluded. The primary efficacy outcome is the rate of change in brain white matter hyperintensity volume on magnetic resonance imaging, a surrogate marker of presumed ischemic damage, between baseline and 24 months follow-up. Secondary outcomes include additional neuroradiological and clinical measures of efficacy and safety. Exploratory outcomes include high-dose rivaroxaban pharmacokinetic modeling. Conclusion: Should RISAPS demonstrate noninferior efficacy and safety of high-dose rivaroxaban in this APS subgroup, it could justify larger prospective randomized controlled trials.

19.
Res Pract Thromb Haemost ; 7(8): 102240, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38193047

RESUMO

Direct oral anticoagulants (DOACs) have been a welcome addition to clinical practice due to the practical advantages they confer over traditional anticoagulants. In many countries, DOACs are now used as first-line treatment for the management of venous thromboembolism (VTE). Traditional anticoagulants allow for a degree of individualization, either through monitoring the international normalized ratio in the case of vitamin-K antagonists or through dose titration according to bodyweight in the case of low-molecular-weight heparin. However, the use of fixed doses and removal of the need for routine monitoring has created uncertainty in prescribing DOACs for patients at the extremes of bodyweight, renal function, and patients with liver impairment, who were not well represented in the DOAC licensing clinical trials. The discipline of pharmacokinetics is concerned with the movement of drugs through the body. Although the extremes of bodyweight and renal and liver function will influence the pharmacokinetics of DOACs, are these changes significant enough to affect clinical outcomes of bleeding and thrombosis? In other words, can the fixed-dosing strategy of DOACs accommodate these differences in physiology? In this review, we recap key pharmacokinetic principles for drug dosing; review venous thromboembolism trial and real-world data on patients prescribed DOACs at the extremes of bodyweight, renal function, and liver function; relate this to the pharmacokinetic properties of DOACs; and summarize the state of the field and current unknowns.

20.
Res Pract Thromb Haemost ; 7(2): 100072, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36861116

RESUMO

Background: There is increasing recognition that menstruating women prescribed anticoagulants experience heavy menstrual bleeding. Objectives: The aim of this study is to report the extent of bleeding in menstruating women after commencing anticoagulants and the impact it has on their quality of life. Methods: Women aged 18 to 50, initiated on anticoagulant therapy, were approached to take part in the study. In parallel, a control group of women was also recruited. Women were asked to complete the menstrual bleeding questionnaire and a pictorial blood assessment chart (PBAC) during their next 2 menstrual cycles. Differences between the control and anticoagulated group were compared. Significance was considered at < .05. Ethics committee approval: REC reference: 19/SW/0211. Results: Fifty-seven women in the anticoagulation and 109 women in the control group returned their questionnaires. Women in the anticoagulated group reported an increase in the median length of their menstrual cycle from 5 to 6 days after commencing anticoagulation, compared to 5 days for women in the control group (P < .05). Anticoagulated women reported significantly higher PBAC scores as compared to the control group (P < .05), with two-thirds of women in the anticoagulation group reporting heavy menstrual bleeding. Women in the anticoagulation group reported worsening quality of life scores following the initiation of anticoagulation, compared with women in the control group (P < .05). Conclusion: Heavy menstrual bleeding occurred in two-thirds of women commencing anticoagulants, who completed a PBAC, which had negative impact on their quality of life. Clinicians commencing anticoagulation therapy should be mindful of this, and recognized measures should be taken to help minimize this problem for menstruating individuals.

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