Old and new anticoagulants

2011 ◽  
Vol 31 (01) ◽  
pp. 21-27 ◽  
Author(s):  
U. Harbrecht

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.

2016 ◽  
Vol 42 (2) ◽  
pp. 146-154 ◽  
Author(s):  
Caio Julio Cesar dos Santos Fernandes ◽  
José Leonidas Alves Júnior ◽  
Francisca Gavilanes ◽  
Luis Felipe Prada ◽  
Luciana Kato Morinaga ◽  
...  

Worldwide, venous thromboembolism (VTE) is among the leading causes of death from cardiovascular disease, surpassed only by acute myocardial infarction and stroke. The spectrum of VTE presentations ranges, by degree of severity, from deep vein thrombosis to acute pulmonary thromboembolism. Treatment is based on full anticoagulation of the patients. For many decades, it has been known that anticoagulation directly affects the mortality associated with VTE. Until the beginning of this century, anticoagulant therapy was based on the use of unfractionated or low-molecular-weight heparin and vitamin K antagonists, warfarin in particular. Over the past decades, new classes of anticoagulants have been developed, such as factor Xa inhibitors and direct thrombin inhibitors, which significantly changed the therapeutic arsenal against VTE, due to their efficacy and safety when compared with the conventional treatment. The focus of this review was on evaluating the role of these new anticoagulants in this clinical context.


2015 ◽  
Vol 9 (4) ◽  
pp. 314
Author(s):  
Tommaso Sacquegna ◽  
Anna Zaniboni ◽  
Andrea Rubboli ◽  
Gaetano Procaccianti ◽  
Michela Crisci ◽  
...  

Vitamin K antagonists, such as warfarin, used in oral anticoagulation therapy currently represent the standard drugs for the primary and secondary prevention of stroke in non-valvular atrial fibrillation (AF), with a relative risk reduction close to 70%. Newer oral anticoagulants, such as direct thrombin inhibitors (<em>i.e</em>., dabigatran) and direct factor Xa inhibitors (<em>i.e</em>., apixaban and rivaroxaban) have been recently compared with warfarin in large randomized trials for stroke prevention in AF. The new oral anticoagulants showed, compared with warfarin, no statistically significant difference in the rate of stroke or systemic embolism in secondary prevention (patients with previous transient ischemic attack or stroke) subgroups. With regard to safety, the risk of intracranial bleeding was reduced with new anticoagulants compared with warfarin. Indirect treatment comparisons of clinical trials on secondary prevention cohorts showed no significant difference in efficacy among apixaban, rivaroxaban, and dabigatran; but dabigatran 110 mg was associated with less intracranial bleedings than rivaroxaban.


2013 ◽  
Vol 6 (2) ◽  
pp. 64-71 ◽  
Author(s):  
Ai-Wei Tang ◽  
Ian Greer

New anticoagulants such as direct factor Xa inhibitors and direct thrombin inhibitors have been recently developed, but their experience in pregnancy is limited. This review therefore aims to systematically search for studies on the use of these newer anticoagulants in pregnancy and the puerperal period. Searches were performed on electronic databases MEDLINE (from 1966), EMBASE (from 1974) and the Cochrane Library, until October 2011 using terms of ‘pregnancy’, ‘puerperium’, ‘breastfeeding’ and names of specific anticoagulants. The search yielded 561 citations and 11 studies (10 on fondaparinux, 1 on ximelagatran) were included. Newer anticoagulants (fondaparinux, hirudin and argatroban) on the limited evidence appear not to have adverse pregnancy outcomes, but there is currently no experience of new oral anticoagulants (rivaroxaban, apixaban, betrixaban or dabigatran) use in pregnancy. There is a need for reporting on new oral anticoagulation use in pregnancy to provide more information about the safety and risks to the fetus in utero.


Scientifica ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Meena P. Rao ◽  
Sean D. Pokorney ◽  
Christopher B. Granger

Atrial fibrillation is the most common arrhythmia and accounts for one-third of hospitalizations for rhythm disorders in the United States. The prevalence of atrial fibrillation averages 1% and increases with age. With the aging of the population, the number of patients with atrial fibrillation is expected to increase 150% by 2050, with more than 50% of atrial fibrillation patients being over the age of 80. This increasing burden of atrial fibrillation will lead to a higher incidence of stroke, as patients with atrial fibrillation have a five- to sevenfold greater risk of stroke than the general population. Strokes secondary to atrial fibrillation have a worse prognosis than in patients without atrial fibrillation. Vitamin K antagonists (e.g., warfarin), direct thrombin inhibitors (dabigatran), and factor Xa inhibitors (rivaroxaban and apixaban) are all oral anticoagulants that have been FDA approved for the prevention of stroke in atrial fibrillation. This review will summarize the experience of anticoagulants in patients with atrial fibrillation with a focus on the experience at the Duke Clinic Research Institute.


VASA ◽  
2009 ◽  
Vol 38 (1) ◽  
pp. 13-29 ◽  
Author(s):  
Haas

Currently available anticoagulants, such as unfractionated heparin, low molecular weight heparins and vitamin K antagonists, have proved effective in the prevention and treatment of thromboembolic disorders. However, these drugs have some drawbacks, such as unpredictability (in the case of unfractionated heparin), non-specificity and parenteral mode of administration, which limit their use in the clinical setting. There is a need for new agents with efficacy similar to that of these classes of anticoagulants and none of their associated drawbacks. Advances are being made in the development of more convenient and more specific drugs, with the aim to improve substantially the prevention and management of thromboembolic disorders. This review will emphasize how the development of an ideal anticoagulant, with potential benefits including high efficacy, safety, low levels of bleeding, fixed dosing, rapid onset of action, ability to bind clot-bound coagulation factors and no requirement for therapeutic monitoring, is a considerable challenge. This review will present the most relevant preclinical data, as well as the clinical studies performed to date, for several drug classes. Direct thrombin inhibitors, such as dabigatran etexilate, will be reviewed, as well as indirect (fondaparinux and idraparinux) and direct (rivaroxaban, apixaban, among others) Factor Xa inhibitors, Factor IXa inhibitors and monoclonal antibodies against Factor IX/IXa.


2016 ◽  
Vol 116 (S 02) ◽  
pp. S41-S49 ◽  
Author(s):  
Alexander Turpie ◽  
Walter Ageno

SummaryVenous thromboembolism (VTE), comprising both deep-vein thrombosis (DVT) and pulmonary embolism (PE), is a serious and common cardiovascular disease associated with the risk of chronic complications, recurrent VTE events and even death. The treatment landscape has, in recent years, seen a paradigm shift from the use of traditional anticoagulants (low-molecular-weight heparin [LMWH] overlapping with and followed by a vitamin K antagonist [VKA]) to non-VKA oral anticoagulants (NOACs). This class of agents, encompassing direct factor Xa inhibitors and direct thrombin inhibitors have shown non-inferior efficacy and better safety to standard of care in randomised controlled trials (RCTs). The direct, oral factor Xa inhibitor rivaroxaban was the first to be approved for treatment of acute DVT and PE and secondary prevention of recurrent VTE events based on data from EINSTEIN DVT and EINSTEIN PE, respectively. Real-world evidence now helps to further support data from RCTs, and also bridges the gap for physicians regarding any areas of clinical uncertainty that may not be addressed by RCTs. XA inhibition with rivaroxaban for Long-term and Initial Anticoagulation in venous thromboembolism (XALIA) was the first large, prospective, observational, real-world study that has investigated the safety and effectiveness profile of rivaroxaban in patients with DVT and PE associated with DVT in routine clinical practice. This article will present the key clinical outcomes from this important global non-interventional study, and will discuss remaining questions to be addressed in Phase IV studies.


2012 ◽  
Vol 02 (01) ◽  
pp. 7-14 ◽  
Author(s):  
Yaroslav Winter ◽  
Richard Dodel ◽  
Alexei Korchounov ◽  
Martin Grond ◽  
Wolfgang H. Oertel ◽  
...  

2009 ◽  
Vol 29 (03) ◽  
pp. 256-259 ◽  
Author(s):  
G. Nowak

SummaryIn contrast to heparins and oral anticoagulants, anti IIa inhibitors (thrombin inhibitors) are able to directly inhibit the protease activity of thrombin and can thereby precisely control the blood coagulation process.Direct thrombin inhibitors are either biosimilars (r-hirudin) or synthetically produced substances (bivalirudin, argatroban, dabigatran). In 1997 r-hirudin was introduced into clinical practice, however due to its narrow therapeutic range and the necessity of drug monitoring it has not gained widespread clinical use by now. Since 2004 and 2005 the synthetic thrombin inhibitors bivalirudin and argatroban, respectively, are available. With dabigatran the first oral synthetic thrombin inhibitor followed in 2008. These four drugs can inhibit even clot bound thrombin and show low plasma protein binding. They differ in respect to route and duration of application as well as elimination from the body, thereby offering a precise inhibition of blood coagulation adjusted to the individual case and without danger of HIT II. These advantages shall be used and advanced by the development of further direct thrombin inhibitors.


2010 ◽  
Vol 103 (01) ◽  
pp. 62-70 ◽  
Author(s):  
Jeffrey Weitz

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.


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