Xa Inhibitor (xa + inhibitor)

Distribution by Scientific Domains

Kinds of Xa Inhibitor

  • direct factor xa inhibitor
  • factor xa inhibitor

  • Selected Abstracts

    Design and Synthesis of Orally Active Pyrrolidin-2-one-Based Factor Xa Inhibitor.

    CHEMINFORM, Issue 42 2006
    Nigel S. Watson
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

    ChemInform Abstract: Practical and Efficient Processes for the Preparation of 4-(4-Aminophenyl)morpholin-3-ones on a Larger Scale: Precursor of Factor Xa Inhibitors.

    CHEMINFORM, Issue 24 2008
    Werner W. K. R. Mederski
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    Novel Factor Xa Inhibitors Based on a 2-Carboxyindole Scaffold: SAR of P4 Substituents in Combination with a Neutral P1 Ligand.

    CHEMINFORM, Issue 49 2004
    Marc Nazare
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Factor Xa Inhibitors Based on a 2-Carboxyindole Scaffold: SAR of Neutral P1 Substituents.

    CHEMINFORM, Issue 48 2004
    Marc Nazare
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Design, Synthesis, and Structure,Activity Relationships of Unsubstituted Piperazinone-Based Transition State Factor Xa Inhibitors.

    CHEMINFORM, Issue 25 2003
    Wenrong Huang
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Substituted Acrylamides as Factor Xa Inhibitors: Improving Bioavailability by P1 Modification.

    CHEMINFORM, Issue 48 2002
    Yonghong Song
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    ChemInform Abstract: Design, Synthesis, and SAR of Substituted Acrylamides as Factor Xa Inhibitors.

    CHEMINFORM, Issue 37 2002
    Yonghong Song
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    Rivaroxaban , an oral, direct Factor Xa inhibitor , lessons from a broad clinical study programme

    Sylvia Haas
    Abstract Anticoagulants are recommended for the prevention and treatment of venous thromboembolism (VTE), prevention of stroke in patients with atrial fibrillation (AF) and secondary prevention in patients with acute coronary syndrome (ACS). There is a clinical need for novel anticoagulants offering improvements over current standard of care, such as fixed oral dosing and no need for routine monitoring. Rivaroxaban, an oral, once-daily, direct Factor Xa inhibitor, has recently completed the RECORD phase III programme for the prevention of VTE in patients undergoing total hip or knee replacement (THR or TKR), an indication for which it is approved in Europe and Canada. It is being investigated in large-scale phase III studies for VTE treatment and prevention of stroke in patients with AF, and phase III studies will soon commence for secondary prevention in patients with ACS. Phase I studies demonstrated that no routine anticoagulation monitoring was required, while phase II studies suggested that fixed daily doses had a wide therapeutic window. The four RECORD studies consistently showed that rivaroxaban was significantly more effective than enoxaparin in the prevention of VTE after THR and TKR, with a similar safety profile. This review describes the development of this novel anticoagulant, from bench to bedside. [source]

    Syntheses of [14C]BAY 59-7939 and its radiolabeled metabolite M-4

    U. Pleiss
    Abstract BAY 59-7939 is a novel, oral, direct Factor Xa inhibitor in clinical development for the prevention and treatment of thromboembolic diseases. Radiolabeled BAY 59-7939 was required for drug absorption, distribution, metabolism and excretion (ADME studies). The BAY 59-7939 was labeled with carbon-14 in the carboxamide group in one step in an overall radiochemical yield of 85% starting from 4-{4-[(5S)-5-(aminomethyl)-2-oxo-1,3-oxazolidin-3-yl]phenyl}mor-pholin-3-one and 5-chlorothiophene-2-[14C]carboxylic acid. The radiolabeled metabolite M-4 was prepared in 77% yield starting from [1- 14C]glycine and 5-chlorothiophene-5-carboxylic acid. Copyright 2006 John Wiley & Sons, Ltd. [source]

    Selective inhibition of Porphyromonas gingivalis growth by a factor Xa inhibitor, DX-9065a

    Kenji Matsushita
    Background:,Porphyromonas gingivalis is a causative bacterium of adult periodontitis. However, there is no drug specific for P. gingivalis and for its virulence factor. Objectives:, The objective of this study was to examine the effects of a new selective inhibitor of activated factor X, DX-9065a, on growth of Porphyromonas gingivalis and other periodontopathic bacteria. Methods:, We incubated P. gingivalis and other periodontopathic bacteria in the presence or absence of DX-9065a and examined the effect of DX-9065a on bacterial growth and trypsin-like activity in its cultures. We also examined the effects of DX9065a on amidolytic activity of purified trypsin-like proteinases (gingipains RgpA and RgpB), from P. gingivalis and on trypsin-like activity in gingival crevicular fluids from patients with adult periodontitis. Results:, DX-9065a selectively inhibited the growth of P. gingivalis and Prevotella intermedia, and its effect on P. gingivalis was bactericidal. Trypsin-like proteinase activity was detected in P. gingivalis, and the activity was strongly inhibited by DX-9065a. DX-9065a even inhibited amidolytic activity of RgpA and RgpB from P. gingivalis. Furthermore, trypsin-like proteinase activity in gingival crevicular fluids was strongly inhibited by DX-9065a. Conclusions:, DX-9065a inhibits P. gingivalis growth in part through to its ability to inhibit the trypsin-like proteinase activity in P. gingivalis and may be useful for a new drug for treatment of adult periodontitis. [source]

    The pharmacokinetics of idraparinux, a long-acting indirect factor Xa inhibitor: population pharmacokinetic analysis from Phase III clinical trials

    Summary.,Background: Idraparinux, a long-acting synthetic pentasaccharide, is a specific antithrombin-dependent inhibitor of activated factor X that has been investigated in the treatment and prevention of thromboembolic events. Objectives: To characterize the population pharmacokinetic profile of idraparinux in patients enrolled in van Gogh and Amadeus Phase III clinical trials. Patients and methods: Idraparinux was administered once-weekly subcutaneously at a dose of 2.5 mg, or 2.5 mg (first dose) and then 1.5 mg for patients with severe renal insufficiency (creatinine clearance <30 mL min,1). A population pharmacokinetic model was developed using data from 704 patients with acute deep-vein thrombosis or pulmonary embolism, 1310 patients suffering from atrial fibrillation, and 40 healthy subjects. Potential covariates analyzed included demographics (age, sex, weight and ethnicity), and serum creatinine and creatinine clearance determinations. Results: A three-compartment model best described idraparinux pharmacokinetics, with interindividual variability on clearance, central volume of distribution, and absorption rate constant; residual variability was low. Typical clearance, central volume of distribution, absorption rate constant and volume of distribution at steady-state were 0.0255 L h,1, 3.36 L, 1.37 h and 30.8 L, respectively. Peak concentration was reached at 2.5 h. The terminal half-life was 66.3 days and time to steady-state was 35 weeks. At steady-state, exposures were similar for patients without and with severe renal impairment receiving adjusted-dose. Creatinine clearance was the most important covariate affecting idraparinux clearance. The particular characteristics of idraparinux , rapid onset of action and long-acting anticoagulant effect , offer interesting clinical perspectives currently under investigation with idrabiotaparinux, the reversible biotinylated form of idraparinux. [source]

    Apixaban, an oral, direct and highly selective factor Xa inhibitor: in vitro, antithrombotic and antihemostatic studies

    P. C. WONG
    Summary.,Background:,Apixaban is an oral, direct and highly selective factor Xa (FXa) inhibitor in late-stage clinical development for the prevention and treatment of thromboembolic diseases. Objective:,We evaluated the in vitro properties of apixaban and its in vivo activities in rabbit models of thrombosis and hemostasis. Methods:,Studies were conducted in arteriovenous-shunt thrombosis (AVST), venous thrombosis (VT), electrically mediated carotid arterial thrombosis (ECAT) and cuticle bleeding time (BT) models. Results:,In vitro, apixaban is potent and selective, with a Ki of 0.08 nm for human FXa. It exhibited species difference in FXa inhibition [FXa Ki (nm): 0.16, rabbit; 1.3, rat; 1.7, dog] and anticoagulation [EC2 (,m, concentration required to double the prothrombin time): 3.6, human; 2.3, rabbit; 7.9, rat; 6.7, dog]. Apixaban at 10 ,m did not alter human and rabbit platelet aggregation to ADP, ,-thrombin, and collagen. In vivo, the values for antithrombotic ED50 (dose that reduced thrombus weight or increased blood flow by 50% of the control) in AVST, VT and ECAT and the values for BT ED3 (dose that increased BT by 3-fold) were 0.27 0.03, 0.11 0.03, 0.07 0.02 and > 3 mg kg,1 h,1 i.v. for apixaban, 0.05 0.01, 0.05 0.01, 0.27 0.08 and > 3 mg kg,1 h,1 i.v. for the indirect FXa inhibitor fondaparinux, and 0.53 0.04, 0.27 0.01, 0.08 0.01 and 0.70 0.07 mg kg,1 day,1 p.o. for the oral anticoagulant warfarin, respectively. Conclusions:,In summary, apixaban was effective in the prevention of experimental thrombosis at doses that preserve hemostasis in rabbits. [source]

    A dose escalation study of YM150, an oral direct factor Xa inhibitor, in the prevention of venous thromboembolism in elective primary hip replacement surgery

    Summary.,Background:,YM150, a new oral direct factor Xa inhibitor is used as prophylaxis for venous thromboembolism (VTE), a well-known risk after orthopaedic surgery. Objectives:,To assess the safety and efficacy of thromboprophylaxis with YM150 in a dose escalation study. Patients/methods:,Patients (174) undergoing hip replacement surgery were randomized per cohort to oral once daily YM150 or subcutaneous enoxaparin (40 mg daily) in a 4:1 ratio for 7,10 days treatment. The YM150 doses were 3, 10, 30 and 60 mg by sequential four-dose escalation cohorts. The primary endpoint was major and/or clinically relevant non-major bleeding. The incidence of VTE was defined as a composite of verified symptomatic events and/or positive findings at bilateral venography on the last treatment day. An independent adjudication committee evaluated blindly the outcomes of the open-label study. Results:,No major and three clinically relevant non-major bleeds were reported, 1 (2.9%; 95% CI, 0.1,15.1) in the 3 mg and 2 (5.7%; 95% CI, 1.0,18.8) in the 10 mg YM150 dose groups. Of 147 patients (84%) with an evaluable venogram, VTE was observed in 51.9% (95% CI, 31.9,71.4), 38.7% (95% CI, 22.6,57.0), 22.6% (95% CI, 9.7,39.4), and 18.5% (95% CI, 7.5,36.5) in the YM150 dose groups 3, 10, 30 and 60 mg, respectively. A significant YM150 dose-related trend in VTE incidence was found (P=0.006). VTE with enoxaparin was 38.7% (95% CI, 22.6,57.0). Conclusions:,YM150, 10,60 mg daily, starting 6,10 h after primary hip replacement, was shown to be safe, well tolerated and effective. [source]

    Inhibition and reversal of platelet-rich arterial thrombus in vivo: direct vs. indirect factor Xa inhibition

    Summary.,Background/objective: The efficacy of a direct factor (F)Xa inhibitor, ZK-807834, was compared with indirect inhibition by enoxaparin for inhibition and deaggregation of acute platelet-rich thrombi in a well-characterized porcine carotid injury model. Methods: A crush injury was performed on a randomly chosen carotid artery and the thrombus allowed to propagate for 30 min. Pigs then received intravenous drug for 35 min: ZK-807834-Dose 1 (40 g kg,1 bolus +,1.5 g kg,1 min,1 infusion, n = 6); ZK-807834-Dose 2 (20 g kg,1 bolus +,0.75 g kg,1 min,1 infusion; n = 6); enoxaparin (1 mg kg,1 bolus; n = 6); or saline (n = 6). Five minutes after drug initiation, the contralateral artery was injured. Thrombus size was monitored by scintillation detection of autologous 111In-platelets. Results: The prothrombin time ratio was 2.2 0.1; 1.4 0.3; 1.2 0.9 and 1.1 0.2, respectively. ZK-807834-Dose 1 significantly inhibited carotid platelet deposition (525 226 106 cm,2; P = 0.008), whereas ZK-807834-Dose 2 (2325 768) and enoxaparin (1236 383) were not different from saline (2776 642). Thrombus deaggregation was greatest for animals receiving ZK-807834-Dose 1 (473 185). Neither ZK-807834-Dose 2 (1588 480) nor enoxaparin (1618 686) was different from saline control (2222 598). Conclusions: Direct FXa inhibition with ZK-807834, at a prothrombin time ratio of 2.2, effectively inhibits thrombosis and promptly deaggregates thrombi induced by arterial injury. In contrast, indirect FXa inhibition with enoxaparin was ineffective. [source]

    Laboratory monitoring of new anticoagulants,

    Donna D. Castellone
    Maintaining a balance between bleeding and clotting has always been a challenge in treating coagulation disorders. A perturbation in that balance can be associated with substantial morbidity and mortality. As a result, anticoagulant monitoring is extremely important, and inappropriate testing may lead to complications. There are now a variety of new anticoagulant drugs in clinical use including several direct thrombin inhibitors (DTIs), such as argatroban, bivalirudin, and hirudin, as well as a Factor Xa inhibitor, fondaparinux. There are pitfalls associated with some of the currently used laboratory monitoring tests, and newer alternative laboratory monitoring tests have been investigated (Walenga and Hoppensteadt, Semin Thromb Hemost 2004;30:683,695). In addition, laboratory testing can assist with transitioning patients from DTI to warfarin therapy. Am. J. Hematol. 2010. 2009 Wiley-Liss, Inc. [source]

    Latest news and product developments

    PRESCRIBER, Issue 21 2008
    Article first published online: 2 DEC 200
    Osteoporosis guideline A new guideline on the management of osteoporosis in men over 50 and post-menopausal women has been published by the National Osteoporosis Guideline Group (www.shef.ac.uk/NOGG), a group of organisations representing health professionals and patients, with funding from several pharmaceutical companies. The guideline recommends using the FRAX tool (www.shef.ac.uk/FRAX) to assess the 10-year fracture risk in individuals with risk factors to facilitate targeting DXA scans to measure bone mineral density. Patients who have already sustained a fragility fracture should be treated without risk assessment. Treatment recommendations are similar to those published in draft NICE guidance on primary and secondary prevention, selecting alendronate as the drug of first choice for most patients. Efalizumab efficacy A multicentred postapproval trial has demonstrated long-term efficacy and a favourable safety profile for efalizumab (Raptiva) in moderate to severe chronic plaque psoriasis. The CONTROL II study, presented in September at the 17th EADV congress in Paris, was conducted at 170 sites in 18 European countries and involved 1255 patients who had failed to respond to traditional systemic therapies. In this non-blinded study, 68 per cent of participants achieved the primary efficacy end-point and showed improvement within the first 12 weeks; control was maintained in responding patients who continued treatment. Adverse effects were graded as mild or moderate and similar to those reported in earlier studies. There was no evidence of an increase in malignancies or infections. New oral anticoagulant Rivaroxaban (Xarelto), an oral factor Xa inhibitor, has been introduced for the prevention of venous thrombo-embolism in patients undergoing elective hip or knee replacement surgery. Compared with the low molecular weight heparin enoxaparin (Clexane), rivaroxaban has been shown to reduce the risk of venous thrombosis by 70 per cent after hip replacement and by 49 per cent after knee replacement; the risk of bleeding was similar. At the recommended dose of 10mg once daily, prophylaxis after hip surgery lasts five weeks and costs 157; prophylaxis after knee surgery lasts two weeks and costs 63. New products UCB Pharma has introduced lacosamide (Vimpat) as adjunctive treatment of partial-onset epilepsy with or without secondary generalisation in patients aged 16 and over. A month's treatment at the recommended maintenance dose of 100-200mg twice daily costs approximately 73-140. A new non-nucleoside reverse transcriptase inhibitor (NNRI) is available for the treatment of HIV-1 infection in combination with a boosted protease inhibitor (PI) and other antiretrovirals in treatment-experienced adults. Etravirine (Intelence) costs approximately 320 for one month's treatment at the recommended dose of 200mg twice daily. Voltarol Pain-Eze (diclofenac) 12.5mg tablets are now available without prescription; a pack of 18 tablets costs 5.99. Atypicals and EPS risk Atypical antipsychotics are not associated with a significantly lower risk of extra-pyramidal symptoms than first-generation agents such as perphenazine (Fentazin), a new analysis of the CATIE study has shown (Br J Psychiatry 2008;193:279,88). CATIE was a large trial comparing the efficacy and safety of antipsychotics in the treatment of schizophrenia in which perphenazine was a representative first-generation agent (Am J Psychiatry 2006;163:611,22). This analysis found no differences in the risk of parkinsonism, dystonia, akathisia or tardive dyskinesia between perphenazine and the newer antipsychotics; use of antiparkinsonian medication was higher with risperidone and lower with quetiapine (Seroquel). Mental health website A new website offering information about mental illnesses and drug treatment has been launched by the United Kingdom Psychiatric Pharmacy Group (UKPPG), the College of Mental Health Pharmacists (CMHP), the Pharmaceutical Schizo-phrenia Initiative (PSI) and the National Institute for Mental Health in England (NIMHE). www.choiceandmedication.org.uk includes information about 17 mental illnesses and a large number of drug treatments. It offers links to other sites offering information and downloadable leaflets, help to identify the local mental health trust and downloadable charts comparing treatments for each indication. [source]

    Absorption, distribution, metabolism and excretion of YM466, a novel factor Xa inhibitor, in rats

    Yuji Mano
    YM466 is a novel factor Xa inhibitor for the treatment of thrombosis. The absorption, distribution, metabolism and excretion of YM466 were investigated in male Fisher rats after a single oral administration. YM466 was absorbed rapidly from all segments of the gastrointestinal tract except the stomach. After oral dosing, the plasma concentration of 14C-YM466 reached a maximum within 0.5h, and declined rapidly with an elimination half-life of 0.64h. The unchanged YM466 accounted for almost all of its radioactivity, suggesting a minimal metabolism in rats. This was also supported by the finding that no metabolites were observed in bile and urine after oral dosing of 14C-YM466. The distribution of 14C-YM466 in tissue was evaluated and the liver and kidney were the organs with radioactivity concentrations consistently higher than that of plasma. Cumulative biliary and urinary excretion of radioactivity in bile duct-cannulated rats was 29.5% and 7.6%, respectively, indicating prominent excretion into bile after oral dosing. This was consistent with the finding that 76.1% and 25.2% of radioactivity dosed were excreted to faeces and urine, respectively, after i.v. dosing. These results suggest that YM466 was rapidly absorbed and then subjected to biliary excretion with a minimal metabolism after oral dosing to rats. Copyright 2004 John Wiley & Sons, Ltd. [source]

    From heparins to factor Xa inhibitors and beyond

    S. Alban
    Abstract Despite some disadvantages, unfractionated heparin (UFH) and oral anticoagulants have been the only anticoagulants for prophylaxis and therapy of thromboembolic disorders for several decades. Based on the increasing knowledge of the structure and pharmacology of heparin, low molecular weight heparins (LMWH) have been developed in the 1980s. Compared to UFH, their advantages are mainly based on their reduced nonspecific binding to proteins and cells resulting in improved pharmacokinetics. In 1991, LMWH were declared as the most efficient prophylaxis in high-risk patients. Although the use of LMWH is increasing and they are today also applied for therapy and in other indications like acute coronary syndrome, they are considered not optimal concerning efficacy and safety. With the approval of fondaparinux for the prevention of venous thromboembolic disease in high-risk orthopedic patients, there might be a paradigm shift in the field of anticoagulants. Fondaparinux, a synthetic, chemically defined pentasaccharide, is the first selective inhibitor of factor Xa. By its highly specific binding to antithrombin, it selectively inhibits factor Xa and consequently prevents thrombin generation. In contrast to UFH and LMWH, it does not bind to any other cells and other proteins than antithrombin. This leads to a favourable linear pharmacokinetic profile, allowing once-daily subcutaneous application of a fixed dose without monitoring in thromboembolism prophylaxis. In addition to the evaluation of fondaparinux for further indications, chemical modifications of this pentasaccharide such as the long-acting idraparinux are currently under investigation. [source]

    Factor Xa or thrombin: is factor Xa a better target?

    Summary., Existing vitamin K antagonists (VKAs) have drawbacks that limit their effectiveness, safety, and overall frequency of use. Oral anticoagulants in development with targeted action against individual coagulation factors, specifically direct factor (F) Xa and IIa inhibitors, appear to have pharmacokinetic and pharmacodynamic properties that overcome the limitations of the VKAs. Based on the theory of how coagulation factors interact, on the results of in vitro studies, and on clinical outcomes, there is accumulating evidence that FXa may represent a better target for inhibition than FIIa. This is based on an understanding of the amplified nature of coagulation factor interactions and fibrin formation, the need for smaller doses of an anticoagulant to block coagulation progression earlier in the sequence of reactions, the evidence for incomplete suppression of thrombin generation with direct thrombin inhibitors, evidence for rebound hypercoagulability with thrombin inhibitors, and clinical results with the indirect, parenteral, FXa inhibitor (fondaparinux), as well as early phase II results of new oral Xa and IIa inhibitors compared with enoxaparin. The latter studies, although not comparative, provide some evidence for the effectiveness and safety of Xa inhibitors at a range of doses not seen with the direct IIa inhibitors. [source]

    Update on Atrial Fibrillation: Part I

    Irina Savelieva M.D.
    Abstract Atrial fibrillation (AF) is an epidemic, affecting 1% to 1.5% of the population in the developed world. Projected data from the population-based studies suggest that the prevalence of AF will grow at least 3-fold by 2050. The health and economic burden imposed by AF and AF-related morbidity is enormous. Atrial fibrillation has a multiplicity of causes ranging from genetic to degenerative, but hypertension and heart failure are the commonest and epidemiologically most prevalent conditions associated with AF as both have been shown to create an arrhythmogenic substrate. Several theories emerged regarding the mechanism of AF, which can be combined into two groups: the single focus hypothesis and the multiple sources hypothesis. Several lines of evidence point to the relevance of both hypotheses to the mechanism of AF, probably with a different degree of involvement depending on the variety of AF (paroxysmal or persistent). Sustained AF alters electrophysiological and structural properties of the atrial myocardium such that the atria become more susceptible to the initiation and maintenance of the arrhythmia, a process known as atrial remodeling. Angiotensin II has been recognized as a key element in atrial remodeling in association with AF opening the possibility of exploitation of "upstream" therapies to prevent or delay atrial remodeling. The clinical significance of AF lies predominantly in a 5-fold increased risk of stroke. The limitations of warfarin prompted the development of new antithrombotic drugs, which include anticoagulants, such as direct oral thrombin inhibitors (dabigatran) and factor Xa inhibitors (rivaroxaban, apixaban). Novel mechanical approaches for the prevention of cardioembolic stroke have recently been evaluated: percutaneous left atrial appendage occluders, minimally invasive surgical isolation of the left atrial appendage, and implantation of carotid filtering devices. Copyright 2008 Wiley Periodicals, Inc. [source]