Anticoagulant agents are used to reduce the risk of thromboembolic complications in patients with atrial fibrillation or deep vein thrombosis. Several new generation of oral anticoagulants have been approved. These novel oral anticoagulants (NOACs) include direct thrombin inhibitors, dabigatra etexilate, and the direct factor Xa inhibitors, rivaroxaban, apixaban and edoxaban. This review evaluates NOACs-related gastrointestinal bleeding and summarizes the ideal management strategies based on the guideline suggested by American Society for Gastrointestinal Endoscopy.
Anticoagulants* ; Antithrombins ; Atrial Fibrillation ; Endoscopy ; Endoscopy, Gastrointestinal ; Factor Xa Inhibitors ; Gastrointestinal Hemorrhage ; Hemorrhage ; Humans ; Rivaroxaban ; Thromboembolism ; Venous Thrombosis

The fine structure of enoxaparin sodium samples with different degree of 1,6-anhydro derivatives were analyzed with polyacrylamide gel electrophoresis, high performance liquid chromatography, ultraviolet spectroscopy, infrared spectroscopy and nuclear magnetic resonance spectroscopy. A further study of anticoagulation activity of enoxaparins was performed, including those on their inhibition activities of coagulation factor Xa (FXa) and thrombin (FIIa). The results showed that the anti-FXa and -FIIa activities of enoxaparins with different degree of 1,6-anhydro derivatives (20.0%-39.7%) with similar structure characteristics, had decreasing tendency when the degree of 1,6-anhydro derivatives increased. Especially, the anti-FXa activity was sensitive to the change of the degree of 1,6-anhydro derivatives.
Anticoagulants ; chemistry ; Enoxaparin ; chemistry ; Factor Xa Inhibitors ; chemistry ; Thrombin ; antagonists & inhibitors

No abstract available.
Anticoagulants

Regulatory approvals of non-vitamin K antagonist oral anticoagulants (NOACs) have been based on large randomized phase III trials evaluating dabigatran, rivaroxaban, apixaban, or edoxaban relative to warfarin for atrial fibrillation (AF). The results of the trials showed that all NOACs were at least non-inferior to warfarin in the prevention of stroke/thromboembolism and showed lower rates of intracranial bleeding than those associated with warfarin. However, the trials were designed differently, varied in the inclusion/exclusion criteria, and used either one dose or a low/high dose of the NOAC drug. Some of these differences have challenged the ability to directly compare various NOACs, and comparative data on effectiveness and intracranial bleeding are sparse in “real-world” patients. Real-world data complement data from large randomized phase III trials by providing new aspects of the “real-world” absolute risks of ischemic and hemorrhagic stroke associated with NOACs vs. warfarin. Moreover, “real-world” fragile patients might have been included (e.g., patients with increased risk of bleeding, liver disease, and chronic kidney disease), although these patients would be less represented in trials. This paper introduces recently published real-world data of NOACs and further suggests the recommended dosage of NOACs for Korean patients.
Anticoagulants* ; Atrial Fibrillation ; Complement System Proteins ; Dabigatran ; Factor Xa Inhibitors ; Hemorrhage ; Humans ; Kidney ; Liver Diseases ; Rivaroxaban ; Stroke ; Warfarin

Heparin-induced thrombocytopenia (HIT) is a serious, immune mediated complication of exposure to unfractionated or low-molecular-weight heparin. Though rare, it is a condition associated with high morbidity and mortality that requires immediate change to alternative anticoagulants for the prevention of life-threatening thrombosis. The direct thrombin inhibitors lepirudin and argatroban are currently licensed for the treatment of HIT. Dabigatran, a novel oral anticoagulant (NOAC) with a similar mechanism of action and effective use in other indications, has recently been proposed as another therapeutic option in cases of HIT. This review serves as an introduction to using dabigatran for this purpose, detailing the clinical aspects of its administration, evidence of its performance compared to other anticoagulants, and the preliminary reports of HIT successfully treated with dabigatran. As the literature on this develops, it will need to include clinical trials that directly evaluate dabigatran against the other NOACs and current treatment options.
Anticoagulants ; Antithrombins ; Dabigatran* ; Heparin, Low-Molecular-Weight ; Mortality ; Thrombocytopenia* ; Thrombosis

BACKGROUNDLow molecular weight heparin (LMWH) was more effective than unfractionated heparin (UFH) in treating acute coronary syndrome (ACS). However, it remains uncertain whether LMWH can be used in patients undergoing percutaneous coronary intervention (PCI) instead of UFH. This study aimed to evaluate the efficacy and safety of using enoxaparin instead of UFH in the intervention treatment of patients with coronary heart disease (CHD).

METHODSFrom October 2003 to Febuary 2005, 966 patients with CHD were enrolled into this study. Among 966 patients, 455 patients received the PCI, including 283 patients with Non-ST segment elevation ACS (NSTEACS), 511 patients did not received PCI due to mild, moderate lesions or were suitable for coronary artery bypass graft (CABG). The 966 patients were randomized to enoxaparin group (484 patients) and UFH group (482 patients). Patients in the enoxaparin group were given enoxaparin at least twice subcutaneously (1 mg/kg, q12 h) before catheterization. Plasma anti-Xa activity was determined 1 - 8 hours after the last dose of enoxaparin was determined. The catheterization was performed within 8 hours after the last dose of enoxaparin. The sheath was removed immediately after the procedure. Patients in the UFH group were given UFH 25 mg intravenously before coronary angiography. Additional 65 mg was given intravenously if PCI was to be performed. The sheath was removed 4 hours after the procedure.

RESULTSA total of 227 patients in the enoxaparin group and 228 patients in the UFH group received PCI. In the enoxaparin group, one patient developed acute thrombosis during PCI and resulted in acute myocardial infarction (AMI), no acute or subacute thrombosis was found during hospitalization. In the UFH group, no acute or subacute thrombosis occurred during PCI procedure and hospitalization. Therefore, the incidence of major adverse cardiovascular events (MACEs) during the hospitalization was 0.44% in the enoxaparin group and 0 in the UFH group. In the enoxaparin group, the sheath was removed immediately after the procedure and 8 patients had hematoma on the puncture site. In the UFH group, the sheath was removed 4 hours after the procedure and 20 cases had hematoma on the puncture site. The incidence of hematoma on the puncture site was significantly higher in the UFH group than that in the enoxaparin group (P < 0.05). Anti-Xa activity was determined in 174 patients in LMWH group. The mean anti-Xa activity was (0.87 +/- 0.23) U/ml, and 94.8% of them had anti-Xa activity >0.5 U/ml and 6.9% of the patient >1.2 U/ml. There was no death and AMI occurred in enoxaparin group, but one patient had AMI caused by subacute thrombosis in UFH group during 30-day follow-up. MACE rate at 30-day follow-up was 0 in enoxaparin group and 0.43% in UFH group.

CONCLUSIONSThe results of the study suggest that it is safe and efficient to give enoxaparin at least twice before the PCI procedure, and the sheath can be removed immediately after PCI. For NSTEACS patient who has received enoxaparin more than twice during the hospitalization can undergo PCI directly and no UFH is necessary before or during PCI.

Angioplasty, Balloon, Coronary ; Anticoagulants ; therapeutic use ; Coronary Disease ; therapy ; Enoxaparin ; adverse effects ; therapeutic use ; Factor Xa Inhibitors ; Female ; Heparin ; therapeutic use ; Humans ; Male ; Middle Aged

OBJECTIVETo evaluate the effectiveness and safety of subcutaneous low molecular weight heparin (LMWH) used in acute management of patients with non-ST segment elevation acute coronary syndrome (ACS).

METHODSA total of 102 patients with non-ST segment elevation ACS were treated for at least 48 hours ( > or =5 times) with subcutaneous nadroparin (1 mg/kg each 12 hours). All 102 patients underwent coronary angiographies (CAG) within 8 hours after LMWH injection, followed by immediate percutaneous coronary intervention (PCI).

RESULTSAnti-Xa activity at the time of catheterization was (0.62 +/- 0.18) IU/ml, and 90% of the patients had anti-Xa activity > 0.5 IU/ml. No death, myocardial infarction relapse or emergent revascularization occurred after PCI. Thrombosis and/or embolism occurred in 2 patients (3.5%) during PCI. Mild hemorrhage was observed in 4 patients (3.9%) of PCI group and in 2 patients (4.4%) in CAG group. No major hemorrhage occurred.

CONCLUSIONPCI within 8-12 hours of the last dose after > or =48 hours nadroparin subcutaneous injection seems to be effective and safe.

Acute Coronary Syndrome ; blood ; therapy ; Angioplasty, Balloon ; Anticoagulants ; adverse effects ; therapeutic use ; Factor Xa Inhibitors ; Humans ; Nadroparin ; adverse effects ; therapeutic use

INTRODUCTIONThis study aimed to compare medication adherence and treatment persistence of patients on warfarin versus rivaroxaban in Singapore. A secondary objective was to identify significant covariates influencing adherence.

MATERIALS AND METHODSA retrospective cohort study was conducted where data from September 2009 to October 2014 was retrieved from the hospital electronic databases. Prescription records of rivaroxaban patients with 3 months or more of continuous prescription were extracted and compared against those of patients on warfarin. Primary outcome of adherence was determined based on the medication possession ratio (MPR), while treatment persistence was determined by outpatient clinic appointment gaps.

RESULTSA total of 94 rivaroxaban and 137 warfarin users were analysed by complete case analysis. The MPR of warfarin patients was lower than rivaroxaban patients by 10% (95% CI, 6.4% to 13.6%; P <0.0001). Also, there were more warfarin patients who had gaps in treatment persistence compared to those prescribed rivaroxaban (8.0% vs 1.1%; P = 0.03). Significant factors affecting medication adherence were age and duration of anticoagulant use. For every 10-year increase in age, MPR increased by 1.7% (95% CI, 0.7% to 2.8%). Similarly, for every year increase in duration of use, MPR increased by 1.8% (95% CI, 0.6% to 3.0%). Race, gender, concomitant medication and type of residence were not found to be significant covariates in the multivariable analysis.

CONCLUSIONPatients on rivaroxaban are likely to be more adherent to their prescribed oral anticoagulant with increasing age and duration of treatment influencing adherence.

Adult ; Age Factors ; Anticoagulants ; therapeutic use ; Databases, Factual ; Factor Xa Inhibitors ; therapeutic use ; Female ; Humans ; Male ; Medication Adherence ; statistics & numerical data ; Middle Aged ; Pulmonary Embolism ; drug therapy ; Retrospective Studies ; Rivaroxaban ; therapeutic use ; Singapore ; Venous Thrombosis ; drug therapy ; Warfarin ; therapeutic use

No abstract available.
Anticoagulants* ; Hemorrhage*

Anticoagulants ; Antithrombins/therapeutic use* ; Coronary Disease ; Heparin ; Hirudins ; Humans ; Peptide Fragments ; Percutaneous Coronary Intervention ; Recombinant Proteins ; Treatment Outcome