scholarly journals Applied Nanotechnologies in Anticoagulant Therapy: From Anticoagulants to Coagulation Test Performance of Drug Delivery Systems

Applied Nano ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 98-117
Author(s):  
Yuri B. G. Patriota ◽  
Luíse L. Chaves ◽  
Evren H. Gocke ◽  
Patricia Severino ◽  
Mônica F. R. Soares ◽  
...  

Heparin-based delivery systems have been explored to improve their therapeutic efficacy and to reduce toxicity for different administration routes. Regardless of the applied drug delivery system (DDS), the evaluation of anticoagulant performance is instrumental for the development of a suitable DDS. The understanding of the range of anticoagulant assays, together with their key applications and limitations, is essential both within the context of scientific research and for clinical usage. This review provides an overview of the current anticoagulant therapy and discusses the advantages and limitations of currently available anticoagulant assays. We also discuss studies involving low-molecular-weight heparin (LMWH)-based nanocarriers with emphasis on their anticoagulation performance. Conventional anticoagulants have been used for decades for the treatment of many diseases. Direct oral anticoagulants have overcome some limitations of heparins and vitamin K antagonists. However, the lack of an accurate laboratory assessment, as well as the lack of a factor “xaban” (Xa) inhibitor reversal agent, remains a major problem associated with these anticoagulants. LMWHs represent anticoagulant agents with noteworthy efficacy and safety, and they have been explored to improve their outcomes with various nanocarriers through several administration routes. The main problems related to LMWHs have been surmounted, and improved efficiency may be achieved through the use of DDSs.

2019 ◽  
Vol 15 (1) ◽  
pp. 49-53
Author(s):  
V. I. Petrov ◽  
O. V. Shatalova ◽  
A. S. Gerasimenko ◽  
V. S. Gorbatenko

Aim. To study the frequency of prescribing antithrombotic agents in patients with non-valvular atrial fibrillation (AF) who were hospitalized in the cardiology department of a multidisciplinary hospital.Material and methods. A retrospective one-time study of medical records of 765 patients with non-valvular AF treated in the cardiology department of a multidisciplinary hospital in 2012 and 2016 was performed.Results. All patients were stratified in three groups depending on the CHA2DS2-VASc score. The frequency of prescribing antithrombotic agents was evaluated in each group. A low risk of thromboembolic complications was found in 1% (n=3) of patients in 2012 and 0.6% (n=3) in 2016. All these patients received antithrombotic agents. CHA2DS2-VASc=1 was found in 6% (n=15) of patients with AF in 2012 and in 3.4% (n=17) in 2016. A significant number of patients in this group received anticoagulant therapy with vitamin K antagonists (warfarin) or with direct oral anticoagulants. A high risk of thromboembolic complications (CHA2DS2-VASc≥2) was found in 93% of patient (n=245) in 2012 and in 96% (n=482) in 2016. Anticoagulant therapy was prescribed in 70.2% (n=172) patients with high risk in 2012 and 80% (n=387) in 2016. However, some patients with high risk of thromboembolic complications did not have the necessary therapy.Conclusion. Positive changes in the structure and frequency of prescribing anticoagulant drugs in patients with AF and a high risk of thromboembolic complications were found during the years studied. 


2018 ◽  
Vol 12 (4) ◽  
pp. 235-244
Author(s):  
Gualtiero Palareti

Venous thromboembolism, a frequent and severe disease, has clinically important early and late complications and a strong tendency to recur. Anticoagulant therapy is the mainstay of treatment, performed by immediate administration of: i) parenteral anticoagulants followed by vitamin K antagonists, either dabigatran or edoxaban, two direct oral anticoagulants (DOACs); or ii) direct rivaroxaban or apixaban, two DOACs that can be used as single-drug approach. Treatment should last no less than 3 months in all patients though how long it should last thereafter is a more complex issue. The risk of recurrence results from several event- or patient-associated factors. Some patients have low risk and may be treated for 3 to 6 months only. Others (the majority) have a high risk of recurrence (approximately 50% in 10 years). Unfortunately, the protective effect of anticoagulation against recurrence is present only during treatment and is lost when therapy is stopped. For this reason, international guidelines recommend that there is no pre-definite period of anticoagulation (e.g. 1 or 2 years, and so on) in patients at high risk and suggest instead indefinite (extended) anticoagulation, provided there is no high risk of bleeding. When the decision is difficult, adjunctive criteria may be adopted, such as male sex and abnormal D-dimer assessed after anticoagulation is stopped, to identify patients at high risk who need indefinite therapy. The use of DOACs, especially at lower doses with a lower risk of bleeding, may make indefinite anticoagulation for patients easier.


VASA ◽  
2019 ◽  
Vol 48 (5) ◽  
pp. 389-392 ◽  
Author(s):  
Paul Gressenberger

Summary. Administration of direct oral anticoagulants (DOACs) for the treatment of venous thrombotic events (VTE) or non-valvular atrial fibrillation (AF) is now standard of care and has demonstrated clinical efficacy and safety in numerous clinical studies. Usually these substances have lower overall mortality and less risk of cerebral hemorrhage, but depending on the substance and study, they are more likely to cause gastrointestinal bleeding than vitamin K antagonists (VKA), the medication that used to be standard for VTE and AF. Since DOACs have very short plasma elimination half-lives compared to VKA, for most bleeding events, expert opinions suggest that withdrawal of DOACs and supportive care will likely suffice to stop a bleeding episode. Because there is a bleeding risk associated with DOACs, reversal strategies may be needed if a patient receiving DOAC therapy bleeds during surgery or an invasive procedure. So far, idarucizumab has been the only available antidote that binds specifically to dabigatran and safely and quickly reverses its anticoagulant effects. Idarucizumab has no effects on anti Xa inhibitors or other anticoagulants. To date, treatment of serious, life-threatening bleeds in patients with anti-Xa-inhibitor has involved 4 factor prothrombin complex concentrates (PCC). PCC restores normal hemostasis laboratory values in most patients with major bleeding events after anti Xa inhibitor intake. Recently, the US Food and Drug Administration (FDA) approved andexanet alfa as the first specific antidote for the anti-Xa inhibitors apixaban and rivaroxaban. So far clinical experience with this substance and data comparing it with PCC are lacking. Currently ciraparantag is under investigation as a universal reversal agent for all DOACs and low molecular weight heparin as well. Because it is so broadly applicable, ciraparantag might be a good future option for the management of most bleeding complications under anticoagulant treatment. The aim of this review is to summarize recent study data and recommendations on nonspecific and specific DOAC reversal strategies and to present the current evidence.


2021 ◽  
Vol 17 (4) ◽  
Author(s):  
Gianni Turcato ◽  
Arian Zaboli ◽  
Andrea Tenci ◽  
Giorgio Ricci ◽  
Massimo Zannoni ◽  
...  

Closed chest traumas are frequent consequences of falls in the elderly. The presence of concomitant oral anticoagulant therapy can increase the risk of post-traumatic bleeding even in cases of trauma with non-severe dynamics. There is limited information about the differences between vitamin K antagonists and direct oral anticoagulants in the risk of post-traumatic bleeding. To assess differences in the risk of developing intra-thoracic hemorrhages after chest trauma with at least one rib fracture caused by an accidental fall in patients over 75 years of age taking oral anticoagulant therapy. This study involved data from four emergency departments over two years. All patients on oral anticoagulant therapy and over 75 years of age who reported a closed thoracic trauma with at least one rib fracture were retrospectively evaluated. Patients were divided into two study groups according their anticoagulant therapy. Of the 342 patients included in the study, 38.9% (133/342) were treated with direct oral anticoagulants and 61.1% (209/342) were treated with vitamin K antagonist. A total of 7% (24/342) of patients presented intrathoracic bleeding, while 5% (17/342) required surgery or died as a result for the trauma. Posttraumatic intrathoracic bleeding occurred in 4.5% (6/133) of patients receiving direct oral anticoagulants and 8.6% (18/209) of patients receiving vitamin K antagonist. Logistic regression analysis, revealed no difference in the risk of intrathoracic haemorrhages between the two studied groups. Direct oral anticoagulants therapy presents a risk of post-traumatic intrathoracic haemorrhage comparable to that of vitamin K antagonist therapy.


2018 ◽  
Author(s):  
Sarah Culbreth ◽  
Dirk Varelmann ◽  
Jessica Rimsans

Managing the balance between bleeding risk and the need to treat thromboembolic disease continues to challenge anesthesiologists and interventionalists, particularly as new direct oral anticoagulants (DOAC) are approved for use. While in the hospital, patients are often placed on parenteral anticoagulants that require monitoring to ensure the dynamic changes that occur in acute illness do not lead to excessive or insufficient anticoagulation. Until recently, vitamin K antagonists (VKA) have been the mainstay of therapy in patients with atrial fibrillation and venous thromboembolism. To facilitate procedures and or minimize bleeding, VKAs were either held or its effects reversed by vitamin K, fresh frozen plasma, or four-factor prothrombin complex concentrate to facilitate procedures and minimize bleeding. Those patients on DOACs continue to challenge the interventionist as there is no commercially available targeted reversal agent for all DOACs. When anticoagulation reversal is warranted, timing or urgency of reversal, the mechanism of action of the anticoagulant, half-life of the anticoagulant, risk of bleeding associated with the procedure, end-organ function, and the patient’s risk factors for thrombosis and bleeding should be considered. This chapter briefly reviews anticoagulants and reversal strategies. This review contains 1 figure, 10 tables, and 53 references. Key Word: activated prothrombin complex concentrate, anticoagulation, antithrombotic, life-threatening bleeding, reversal, periprocedural, prothrombin complex concentrate, surgery


2020 ◽  
Author(s):  
Ammar Alsamarrai ◽  
Nicola Eaddy ◽  
Elizabeth Curry

Abstract Anticoagulant-related nephropathy (ARN) is a clinical syndrome of acute kidney injury in patients taking vitamin K antagonists or direct oral anticoagulants. It is associated with increased mortality and there is no specific treatment. We report the case of a 78-year-old man on dabigatran who developed macroscopic haematuria and acute kidney injury 2 weeks after mitral valve repair, reaching a peak creatinine of 415 µmol/L from a normal baseline, which was successfully treated with one course of idarucizumab. This case illustrates the efficacy of an anticoagulant reversal agent for the treatment of ARN.


2020 ◽  
Vol 55 (2) ◽  
pp. 261-264
Author(s):  
John N. Maneno ◽  
Genevieve Lynn Ness

The recent shortage of protamine prompted an investigation of alternatives for reversal of unfractionated heparin. Heparin is an anticoagulant utilized in the hospital setting. Available options for anticoagulation include direct oral anticoagulants, vitamin K antagonists, thrombin inhibitors, low-molecular-weight heparins, and heparin. Protamine is the approved reversal agent for heparin with few alternatives under investigation. Although andexanet was designed as an antidote for apixaban and rivaroxaban, in vitro studies show that in a dose-dependent technique, andexanet had near full reversal of heparin, reversed anti–factor Xa activity, and neutralized anticoagulant effects of activated partial thromboplastin time and thrombin time induced by heparin.


Author(s):  
Gualtiero Palareti

Venous thromboembolism (VTE), a frequent and severe disease, has clinically important early and late complications and a strong tendency to recur. Anticoagulant therapy is the mainstay of treatment, performed by immediate administration of: a) parenteral anticoagulants followed by vitamin K antagonists (VKAs), either dabigatran or edoxaban, two direct oral anticoagulants (DOACs); or b) direct rivaroxaban or apixaban, two DOACs that can be used as single-drug approach. Treatment should last no less than 3 months in all patients though how long it should last thereafter is a more complex issue. The risk of recurrence results from several event- or patient-associated factors. Some patients have low risk and may be treated for 3 to 6 months only. Others (the majority), have a high risk of recurrence (approximately 50% in 10 years). Unfortunately, the protective effect of anticoagulation against recurrence is present only during treatment and is lost when therapy is stopped. For this reason, international guidelines recommend there be no pre-definite period of anticoagulation (e.g. 1 or 2 years, and so on) in patients at high risk and suggest instead indefinite (extended) anticoagulation, provided there is no high risk of bleeding. When the decision is difficult, adjunctive criteria may be adopted, such as male sex and abnormal Ddimer assessed after anticoagulation is stopped, to identify patients at high risk who need indefinite therapy. The use of DOACs, especially at lower doses with a lower risk of bleeding, may make indefinite anticoagulation for patients easier.


2019 ◽  
pp. 14-19
Author(s):  
I. S. Daabul ◽  
A. A. Sokolova ◽  
I. L. Tsarev ◽  
D. A. Napalkov ◽  
V. V. Fomin

In recent years, both Russian and foreign authors have published many papers on anticoagulant therapy for atrial fibrillation (AF). The largest are devoted to the study of direct oral anticoagulants (DOACs), which have appeared in this field since 2009, and their comparison with vitamin K antagonists (VKAs) in terms of efficacy, safety and other important characteristics. There are far fewer studies on DOACs and their comparison with VKAs and with each other in patients with AF and reduced kidney function. Most of them are retrospective. Meanwhile, the prevalence of chronic kidney disease (CKD) in the population is very high, and doctors are faced with a problem of selecting anticoagulant therapy for these patients.Purpose. To assess the effect of VKAs and DOACs on renal function in real clinical practice in patients with AF depending on the stage of CKD.Materials and methods. A prospective single-centre non-randomized non-interventional observational study in parallel groups was conducted. The study included 92 patients with AF and CKD of 1-4 stages (S1-S4). The comparison group consisted of 35 patients with AF without concomitant CKD. The patients’ age ranged from 44 to 94 years (mean age was 72.2 ± 8.5 years). Patients of both groups received anticoagulant therapy with VKA (warfarin) or one of the registered in the Russian Federation DOACs (dabigatran, rivaroxaban, apixaban). During the observation (median was 10 months), follow-up visits were every 3 months. On visits we conducted the evaluation of effectiveness (strokes / TIA and thromboembolic complications) and safety (major and minor hemorrhagic events) of anticoagulant therapy, as well as the dynamics of kidney function (CC by Cockroft-Gault, GFR by CKD-EPI).Results. The main results are devoted to patients with AF and concomitant CKD. Significant dynamics of the kidney function depending on the anticoagulant taken (VKA or representatives of the DOACs class) were not identified. There were not any thromboembolic complications and major bleedings during the observation period. Statistically significant more minor bleedings on any dose of rivaroxaban in comparison with other anticoagulants were identified.Conclusions. In patients with AF and CKD, there was no significant effect of one or another anticoagulant on the kidney function, which is probably related to the concomitant nephroprotective therapy obtained in a large percentage of cases (ACE inhibitors / ARA, calcium antagonists, statins). Therapy with DOACs and warfarin in patients with AF and CKD for an average of 10 months of followup was effective and safe. In case of AF and CKD combination, the use of dabigatran or apixaban seems to be more preferable in relation to minor bleedings, the use of which less often leads to the development of hemorrhagic events. 


2021 ◽  
Vol 17 (5) ◽  
pp. 771-778
Author(s):  
O. V. Averkov ◽  
L. N. Mishchenko

Oral anticoagulant therapy is widely used in different patients for the prevention and treatment of thromboembolic events: in atrial fibrillation, deep vein thrombosis/pulmonary embolism, acute coronary syndrome, in the early postoperative period after orthopedic surgery. Nowadays it is possible to use vitamin K antagonists (warfarin) as well as direct oral anticoagulants (DOAC): dabigatran, rivaroxaban, apixaban and edoxaban. The mai complication of any anticoagulant therapy is bleeding (gastrointestinal, intracranial, etc.), which seriously limits its usage. In this review the incidence of gastrointestinal bleeding (GIB) associated with oral anticoagulants intake was analyzed according to the results of both large randomized and postregistration trials. Furthermore, the effect of age on the risk of GIB development is discussed, and also aspects of the pathophysiology of gastrointestinal mucosa lesions in patients taking DOAC are considered.


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