New oral anticoagulants in development

2010 ◽  
Vol 103 (01) ◽  
pp. 62-70 ◽  
Author(s):  
Jeffrey Weitz
Keyword(s):  
Vitamin K ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Factor Xa ◽  
New Oral Anticoagulants ◽  
Dietary Vitamin ◽  
Multiple Drug ◽  
Coagulation Monitoring ◽  
Advanced Stages

SummaryAlthough currently available anticoagulants are effective for the prevention and treatment of thromboembolic disorders, they have several drawbacks. Low-molecular-weight heparins and fondaparinux produce a predictable level of anticoagulation that obviates the need for coagulation monitoring, but they must be given parenterally, which renders them inconvenient for long-term use. Vitamin K antagonists, such as warfarin, are administered orally, but produce a variable anticoagulant response because genetic polymorphisms, dietary vitamin K intake and multiple drug-drug interactions affect their metabolism. Consequently, coagulation monitoring and frequent dose adjustments are needed to ensure that a therapeutic level of anticoagulation is achieved. This is burdensome for patients and physicians, and costly for the healthcare system. These limitations have prompted the development of new oral anticoagulants that target thrombin or factor Xa and can be given in fixed doses without coagulation monitoring. This paper focuses on the new oral anticoagulants in the most advanced stages of development.

Treatment and secondary prevention of venous thromboembolism in cancer patients

2012 ◽  
Vol 03 (03) ◽  
pp. 121-125
Author(s):  
I. Pabinger ◽  
C. Ay
Keyword(s):  
Clinical Trials ◽  
Venous Thromboembolism ◽  
Cancer Patients ◽  
Oral Anticoagulants ◽  
Factor Xa ◽  
New Oral Anticoagulants ◽  
Phase Iii ◽  
Patients With Cancer ◽  
Potential Use

SummaryCancer is a major and independent risk factor of venous thromboembolism (VTE). In clinical practice, a high number of VTE events occurs in patients with cancer, and treatment of cancerassociated VTE differs in several aspects from treatment of VTE in the general population. However, treatment in cancer patients remains a major challenge, as the risk of recurrence of VTE as well as the risk of major bleeding during anticoagulation is substantially higher in patients with cancer than in those without cancer. In several clinical trials, different anticoagulants and regimens have been investigated for treatment of acute VTE and secondary prophylaxis in cancer patients to prevent recurrence. Based on the results of these trials, anticoagulant therapy with low-molecular-weight heparins (LMWH) has become the treatment of choice in cancer patients with acute VTE in the initial period and for extended and long-term anticoagulation for 3-6 months. New oral anticoagulants directly inhibiting thrombin or factor Xa, have been developed in the past decade and studied in large phase III clinical trials. Results from currently completed trials are promising and indicate their potential use for treatment of VTE. However, the role of the new oral thrombin and factor Xa inhibitors for VTE treatment in cancer patients still has to be clarified in further studies specifically focusing on cancer-associated VTE. This brief review will summarize the current strategies of initial and long-term VTE treatment in patients with cancer and discuss the potential use of the new oral anticoagulants.

Spectrophotometric Assays of Prothrombin in Plasma of Patients Using Oral Anticoagulants

1979 ◽  
Vol 42 (04) ◽  
pp. 1296-1305 ◽  
Author(s):  
R M Bertina ◽  
W van der Marel-van Nieuwkoop ◽  
E A Loeliger
Keyword(s):  
Prothrombin Time ◽  
Vitamin K ◽  
Oral Anticoagulation ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Factor Xa ◽  
Factor V ◽  
Anticoagulant Treatment ◽  
Factor Ii ◽  
K Deficiency

SummaryTwo spectrophotometric assays for prothrombin have been developed and compared with a one stage coagulant and an immunological assay. One of these assays (called the XAPC assay) uses a combination of factor Xa, phospholipid, Ca2+ and factor V as activator of prothrombin, and measures only normal prothrombin. The second (the ECAR assay) uses Echis carinatus venom as activator. This assay measures both normal prothrombin and PIVKA II (protein induced by vitamin K antagonists/absence). Combination of the results obtained by the XAPC and ECAR assays provides rapid and reliable information on the degree of “subcarboxylation” of prothrombin (oral anticoagulation, vitamin K deficiency).For patients on long term anticoagulant treatment the prothrombin time (Thrombotest) shows better correlation with the ratio prothrombin/prothrombin plus PIVKA II (XAPC/ ECAR) than with the factor II concentration. For patients starting the anticoagulant treatment there is no correlation between the Thrombotest time and the XAPC/ECAR ratio.It seems doubtful that (a) spectrophotometric factor II assay(s) will be as useful as the prothrombin time in the control of oral anticoagulation.

Perioperative Management of Patients Receiving New Anticoagulants

2019 ◽  
Vol 25 (19) ◽  
pp. 2149-2157 ◽  
Author(s):  
Massimo Lamperti ◽  
Andrey Khozenko ◽  
Arun Kumar
Keyword(s):  
Vitamin K ◽  
Elective Surgery ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Oral Intake ◽  
Bleeding Risk ◽  
Dietary Vitamin ◽  
Reversal Agent ◽  
Onset Of Action ◽  
Reversal Agents

There is an increased use of oral anticoagulants for the prevention of venous and arterial thrombosis. Vitamin-K antagonists have been used for decades as the main oral anticoagulants but they have the draback a complex therapeutic management, slow onset of action and by a different oral intake caused by dietary vitamin K intake. New non-vitamin K antagonist oral anticoagulants (NOACs) have been developed to overcome the limitations of warfarin. Their management is easier as it requires a fixed daily dose without coagulation monitoring. Although their therapeutic profile is safe, proper attention should be paid in case of unexpected need for the reversal of their coagulation effect and in case a patient needs to have a scheduled surgery. For non-acute cardiac surgery, discontinuation of NOACs should start at least 48 hours prior surgery. Intracranial bleedings associated with NOACs are less dangerous comparing to those warfarin-induced. NOACs need to be stopped ≥24 hours in case of elective surgery for low bleeding-risk procedures and ≥48 hours for high bleeding-risk surgery in patients with normal renal function and 72 hours in case of reduced CrCl < 80. The therapy with NOACs should be resumed from 48 to 72 hours after the procedure depending on the perceived bleeding, type of surgery and thrombotic risks. There are some available NOAC reversal agents acting within 5 to 20 minutes. In case of lack of reversal agent, adequate diuresis, renal replacement therapy and activated charcoal in case of recent ingestion should be considered.

scholarly journals The Severity of Intracranial Hemorrhages Measured by Free Hemoglobin in the Brain Depends on the Anticoagulant Class: Experimental Data

2017 ◽  
Vol 2017 ◽  
pp. 1-4 ◽  
Author(s):  
Kyle M. Ware ◽  
Douglas L. Feinstein ◽  
Israel Rubinstein ◽  
Prudhvi Battula ◽  
Jose Otero ◽  
...  
Keyword(s):  
Vitamin K ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Direct Oral Anticoagulants ◽  
Factor Xa ◽  
Hemoglobin Concentration ◽  
Thrombin Inhibitor ◽  
Free Hemoglobin ◽  
Intracranial Hemorrhages ◽  
The Brain

Background and Purpose. Anticoagulant therapy is broadly used to prevent thromboembolic events. Intracranial hemorrhages are serious complications of anticoagulation, especially with warfarin. Direct oral anticoagulants reduce but do not eliminate the risk of intracranial hemorrhages. The aim of this study is to determine the degree of intracranial hemorrhage after application of anticoagulants without additional triggers. Methods. Rats were treated with different anticoagulant classes (vitamin K antagonists, heparin, direct thrombin inhibitor, and factor Xa inhibitor). Brain hemorrhages were assessed by the free hemoglobin concentration in the brain parenchyma. Results. Vitamin K antagonists (warfarin and brodifacoum) significantly increased free hemoglobin in the brain. Among direct oral anticoagulants, thrombin inhibitor dabigatran also significantly increased free hemoglobin in the brain, whereas treatment with factor Xa inhibitor rivaroxaban did not have significant effect on the free hemoglobin concentration. Conclusions. Our data indicates that the severity of brain hemorrhages depends on the anticoagulant class and it is more pronounced with vitamin K antagonists.

scholarly journals ORAL ANTICOAGULANTS IN THE TREATMENT OF VENOUS THROMBOEMBOLIC COMPLICATIONS: FOCUS ON APIXABAN

2017 ◽  
pp. 56-62 ◽  
Author(s):  
M. Yu. Gilyarov ◽  
E. V. Konstantinova
Keyword(s):  
Vitamin K ◽  
Oral Anticoagulants ◽  
Direct Oral Anticoagulants ◽  
Factor Xa ◽  
Vitamin K Antagonist ◽  
Fixed Dose ◽  
Vein Thrombosis ◽  
Venous Thromboembolic ◽  
Deep Vein

Venous thromboembolism (VTE), comprising deep vein thrombosis and pulmonary embolism, is a common condition associated with a significant clinical and economic burden. Anticoagulant therapy is the mainstay of treatment for VTE. Current guidelines recommend the use of either low molecular weight heparins or fondaparinux overlapping with and followed by a vitamin K antagonist for the initial treatment of VTE, with the vitamin K antagonist continued when long-term anticoagulation is required. These traditional anticoagulants have practical limitations that have led to the development of direct oral anticoagulants that directly target either Factor Xa or thrombin and are administered at a fixed dose without the need for routine coagulation monitoring. The paper reviews results of the trials of apixaban application for treatment and/or long-term secondary prevention of VTE. The paper analyses effectiveness and safety of apixaban in different groups of patients, as well as features of apixaban application in every day practice.

Oral anticoagulant treatment: friend or foe in cardiovascular disease?

Blood ◽  
2004 ◽  
Vol 104 (10) ◽  
pp. 3231-3232 ◽  
Author(s):  
Leon J. Schurgers ◽  
Hermann Aebert ◽  
Cees Vermeer ◽  
Burkhard Bültmann ◽  
Jan Janzen
Keyword(s):  
Cardiovascular Disease ◽  
Vitamin K ◽  
Heart Valves ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Arterial Calcification ◽  
Adverse Side Effect ◽  
Oral Anticoagulant Treatment ◽  
Carboxyglutamic Acid

Abstract Calcification is a common complication in cardiovascular disease and may affect both arteries and heart valves. Matrix γ-carboxyglutamic acid (Gla) protein (MGP) is a potent inhibitor of vascular calcification, the activity of which is regulated by vitamin K. In animal models, vitamin K antagonists (oral anticoagulants [OACs]) were shown to induce arterial calcification. To investigate whether long-term OAC treatment may induce calcification in humans also, we have measured the grade of aortic valve calcification in patients with and without preoperative OAC treatment. OAC-treated subjects were matched with nontreated ones for age, sex, and disease. Calcifications in patients receiving preoperative OAC treatment were significantly (2-fold) larger than in nontreated patients. These observations suggest that OACs, which are widely used for antithrombotic therapy, may induce cardiovascular calcifications as an adverse side effect.

The NOACs: clinical pharmacology

ESC CardioMed ◽  
2018 ◽  
pp. 268-272
Author(s):  
Jeffrey Weitz
Keyword(s):  
Atrial Fibrillation ◽  
Vitamin K ◽  
Active Site ◽  
Randomized Clinical Trials ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Factor Xa ◽  
Vitamin K Antagonist ◽  
Phase Iii ◽  
High Affinity

The limitations of vitamin K antagonists prompted the development of new oral anticoagulants that could be administered in fixed doses without routine coagulation monitoring. Focusing on thrombin and factor Xa because of their prominent roles in coagulation, structure-based design led to the development of small molecules that bind to the active site pockets of these enzymes with high affinity and specificity. Four non-vitamin K antagonist oral anticoagulants are now licensed: dabigatran, which inhibits thrombin, and rivaroxaban, apixaban, and edoxaban, which inhibit factor Xa. In phase III randomized clinical trials that included over 100,000 patients these agents have proven to be at least as effective as vitamin K antagonists for prevention of stroke in patients with non-valvular atrial fibrillation and for treatment of venous thromboembolism, and to produce less bleeding, particularly less intracranial bleeding.

Old and new anticoagulants

2011 ◽  
Vol 31 (01) ◽  
pp. 21-27 ◽  
Author(s):  
U. Harbrecht
Keyword(s):  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Factor Xa ◽  
New Oral Anticoagulants ◽  
Thrombin Inhibitors ◽  
Clotting Factor ◽  
Direct Thrombin Inhibitors ◽  
Self Monitoring ◽  
New Anticoagulants ◽  
Gastrointestinal Side Effects

SummaryVitamin-K-antagonists (VKA) and heparins have been complementary anticoagulants for prevention and treatment of thrombosis for almost 70 years. In contrast to heparins, VKA have not been modified pharmacologically, however treatment surveillance has improved by introducing INR and self-monitoring/management. Disclosure of the molecular basis of interaction with VKORC1, the target enzyme of VKA, has helped to better understand coumarin sensitivity and resistance. New oral anticoagulants have now been approved and stimulated expectations in patients and physicians to get rid of the burdening frequent controls of VKA without loss of efficacy and safety.This review will summarize the development and profile of the new substances. Main difference compared to VKA is their direct mode of action against one clotting factor which is factor IIa in dabigatran and factor Xa in rivaroxaban and other “xabanes” currently under intensive investigation. Half lifes of the new anticoagulants are much shorter than that of the mainly used coumarins (phenprocoumon, warfarin), making “anticoagulation bridging” unnecessary before surgery. Therapeutic width of direct thrombin inhibitors and factor Xa inhibitors is broader and they are given at fixed doses. Clinical studies in thromboprophylaxis, thromboembolism and atrial fibrillation indicate at least non-inferiority or even superior efficacy compared with enoxaparin and VKA at comparable safety outcomes. Limitations of the new substances may arise from gastrointestinal side effects, mode of metabolism and route of elimination. Specific antidots are not available for none of them.Undoubtedly, the new oral anticoagulants are very promising. But, although thousands of study patients already have been treated, there are questions to be answered such as treatment adherence in absence of monitoring, safety and efficacy in risk patients, dosage adjustment and interactions with other drugs, before conclusions can be drawn towards their potential to replace VKA.

Kidney and haemostasis

2015 ◽  
Vol 35 (01) ◽  
pp. 73-76
Author(s):  
K. Andrassy
Keyword(s):  
Renal Insufficiency ◽  
Vitamin K ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Cardiovascular Complications ◽  
Water Soluble ◽  
New Oral Anticoagulants ◽  
Waste Products ◽  
End Stage ◽  
Fgf 23

SummaryRenal insufficiency is characterized by thrombocytopathy, caused by the accumulation of water soluble and protein bound waste products of protein metabolism, which are not adequately eliminated by the kidney. The kidneys also excrete drugs and their metabolites, which accumulate if dosages are not adjusted to the renal function and may cause clinically relevant bleeding (i. e. synthetic penicillins, vitamin K antagonists, new oral anticoagulants). Therefore, each patients kidney function (GFR) ought to be evaluated by the KDIGO guidelines. The survival of chronic renal patients is lowered by increasing cardiovascular complications. Particularly frequent is non-valvular atrial fibrillation. The recommended prophylaxis with vitamin K antagonists for renal insufficiency is hampered by increased bleeding as well as by augmented (coronary) vascular and valvular calcification. It is not known yet whether prophylaxis with vitamin K may prevent this complication. Conclusion: Because new oral anticoagulants are equally or even more effective and cause less bleeding, they may be favoured in future and even in end-stage renal failure if more is known about dosing, safety and efficacy. The measurement of serum FGF 23 concentration may be helpful as a marker for their use.

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