Vitamin K antagonists

2012 ◽  
Vol 32 (04) ◽  
pp. 249-257 ◽  
Author(s):  
T. F. Luscher ◽  
J. Steffel
Keyword(s):  
Atrial Fibrillation ◽  
Venous Thromboembolism ◽  
Drug Interactions ◽  
Vitamin K ◽  
Stroke Prevention ◽  
Vitamin K Antagonists ◽  
Term Treatment ◽  
Thrombin Inhibitor ◽  
Long Term Treatment

SummaryFor the last decades, anticoagulation for stroke prevention in atrial fibrillation (AF) as well as for the prophylaxis and long-term treatment of venous thromboembolism has been entirely based on vitamin K antagonists (VKA). Although very effective under optimal conditions, long-term treatment with these drugs is flawed by the fact that the time in the therapeutic range frequently is suboptimal due to biological factors, drug interactions and compliance.The direct thrombin inhibitor dabigatran, as well as the direct FXa inhibitors rivaroxaban and apixaban provide more consistent anticoagulation and have proven their efficacy and safety against VKAs in several large scale randomized clinical trials for stroke prevention in atrial fibrillation as well as for the treatment and prevention of venous thromboembolism. In view of these convincing data and other advantages such as the lack of mandatory monitoring and only few drug interactions,VKAs will most likely be replaced in a majority of patients for these indications. Based on the most recent trial evidence, the current review discusses the role of VKA treatmentand that of the novel anticoagulants.

scholarly journals The international normalized ratio (INR) as seen in a population of patients with atrial fibrillation and cerebral infarction undergoing long-term treatment with vitamin K antagonists

2015 ◽  
Vol 28 (4) ◽  
pp. 269-272
Author(s):  
Anna Szczepańska-Szerej ◽  
Magdalena Wojtan ◽  
Beata Szajnoga
Keyword(s):  
Atrial Fibrillation ◽  
Cerebral Infarction ◽  
Vitamin K ◽  
Vitamin K Antagonists ◽  
International Normalized Ratio ◽  
Blood Parameters ◽  
Term Treatment ◽  
Adequate Treatment ◽  
Long Term Treatment

Abstract It is estimated that nearly 20% of all cerebral infarctions in the total population are the result of a complication of atrial fibrillation (AF). While oral anticoagulation with vitamin K antagonists (AVKs) substantially reduces this risk, this requires regular monitoring of the international normalized ratio (INR) in order to achieve therapeutic levels (2,0-3,0). The aim of this study was to evaluate a group at high risk of cerebral infarction, among patients with AF undergoing long-term treatment with VKAs, taking into account the significance of therapeutic INR values. The analysed group consisted of 90 acute ischaemic stroke patients with paroxysmal or chronic “non-valvular” AF, receiving treatment with VKAs. As a result of the study, therapeutic INR values (≥ 2) were seen in thirty-five of these individuals (38,8%), while 55 (61,2%) showed non-therapeutic INR values. Moreover, there were no differences in demographics, vascular risk factors, biochemical and morphological blood parameters, mean CHA2DS2-VASc score and TOAST classification between either of the two groups. Furthermore, no additional factor that would increase their risk of cerebral infarction during the adequate treatment with VKAs was found. However, patients with non-therapeutic INR values had a statistically significantly higher frequency of concomitant moderate pathology of the bicuspid valve, p<0.05. Hence, a lack of proper control of INR can proved to be particularly dangerous for this subgroup of patients. Hence, this is a group with an elevated risk of cerebral infarction and therefore requires special oversight of VKA treatment or NOA treatment.

Idiopathic venous thrombosis

2006 ◽  
Vol 26 (01) ◽  
pp. 48-51 ◽  
Author(s):  
S. Haas
Keyword(s):  
Venous Thromboembolism ◽  
Vitamin K ◽  
Vitamin K Antagonists ◽  
Term Treatment ◽  
Bleeding Complications ◽  
Individual Risk ◽  
Long Term Treatment ◽  
Net Clinical Benefit ◽  
The Individual

SummaryIdiopathic venous thromboembolism has been shown to be associated with a high frequency of recurrence. Therefore, the most important aim of long-term treatment is secondary prevention. It has also been shown that long-term anticoagulation with vitamin K antagonists can impressively reduce the rate of recurrence. However, this effect was only maintained during anticoagulation and disappeared after cessation of anticoagulant therapy. Unfortunately, the individual risk of recurrence is not predictable. Therefore, longterm anticoagulation appears beneficial across all subgroups of patients suffering from venous thromboembolism, regardless of the presence of thrombophilia or other burden of the disease. Despite the increasing body of evidence regarding the advantages of long-term anticoagulation, bleeding complications may limit the net clinical benefit of this strategy. Thus, the development of anticoagulants having a low potential for adverse reactions and providing similar beneficial antithrombotic effects to vitamin K antagonists will enhance the readiness for their wide spread use and life long administration.

Long-term quality of VKA treatment and clinical outcome after extreme overanticoagulation in 14,777 AF and VTE patients

2015 ◽  
Vol 113 (04) ◽  
pp. 881-890 ◽  
Author(s):  
Nic J. G. M. Veeger ◽  
Nakisa Khorsand ◽  
Hanneke C. Kluin-Nelemans ◽  
Hilde A. M. Kooistra ◽  
Karina Meijer ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Venous Thromboembolism ◽  
Clinical Outcome ◽  
Vitamin K ◽  
Vitamin K Antagonists ◽  
P Value ◽  
Risk Of Bleeding ◽  
Increased Risk

SummaryVitamin K antagonists (VKA) are widely used in atrial fibrillation and venous thromboembolism (VTE). Their efficacy and safety depend on individual time in the therapeutic range (iTTR). Due to the variable dose-response relationship within patients, also patients with initially stable VKA treatment may develop extreme overanticoagulation (EO). EO is associated with an immediate bleeding risk, but it is unknown whether VKA treatment will subsequently restabilise. We evaluated long-term quality of VKA treatment and clinical outcome after EO. EO was defined as international normalized ratio (INR) ≥ 8.0 and/or unscheduled vitamin K supplementation. We included a consecutive cohort of initially stable atrial fibrillation and venous thromboembolism patients. In EO patients, the 90 days pre- and post-period were compared. In addition, patients with EO were compared with patients without EO using a matched 1:2 cohort. Of 14,777 initially stable patients, 800 patients developed EO. The pre-period was characterised by frequent overanticoagulation, and half of EO patients had an inadequate iTTR (< 65 %). After EO, underanticoagulation became more prevalent. Although the mean time between INR-measurements decreased from 18.6 to 13.2 days, after EO inadequate iTTR became more frequent (62 %), p-value < 0.001. A 2.3 times (95 % confidence interval [CI] 2.0–2.5) higher risk for iTTR< 65 % after EO, was accompanied by increased risk of bleeding (hazard ratio [HR] 2.1;CI 1.4–3.2), VKA-related death 17.0 (HR 17.0;CI 2.1–138) and thrombosis (HR 5.7;CI 1.5–22.2), compared to the 1600 controls. In conclusion, patients continuing VKA after EO have long-lasting inferior quality of VKA treatment despite intensified INR-monitoring, and an increased risk of bleeding, thrombosis and VKA-related death.Note: There have been no previous presentations, reports or publications of the complete data that appear in the article. Parts of the data in this article have been presented as a poster at the American Society of Hematology (ASH) congress 2013, New Orleans, United States.

A worldwide survey to assess the current approach to the treatment of patients with cancer and venous thromboembolism

2013 ◽  
Vol 110 (11) ◽  
pp. 959-965 ◽  
Author(s):  
Anita Aggarwal ◽  
Annemarie van de Geer ◽  
Charles Faselis ◽  
Harry R. Büller ◽  
Marcello Di Nisio ◽  
...  
Keyword(s):  
Venous Thromboembolism ◽  
Vitamin K Antagonists ◽  
Term Treatment ◽  
Current Approach ◽  
Survey Tool ◽  
General Internal ◽  
Patients With Cancer ◽  
First Choice ◽  
Long Term Treatment

SummaryLow-molecular-weight heparin (LWMH) is recommended as the preferred anticoagulant treatment over vitamin K antagonists (VKA) for venous thromboembolism (VTE) in patients with cancer. However, there is uncertainty about the duration and dose of LMWH treatment. Therefore, we designed this multinational survey to assess the current approach to the treatment of patients with cancer and VTE. An electronic survey tool was used to disseminate a survey containing 49 questions on different aspects of the treatment of patients with cancer and VTE, among both thrombosis and non-thrombosis specialists. A total of 229 invitations were sent, and 141 completed the survey (60% of the total). Fifty-eight percent of the respondents were from Europe, 35% from the US and the remaining 7% from other countries. Respondent’s specialties included haematology (23%), oncology (18%), pulmonology (15%) and general internal medicine (15%). LMWH was indicated as the first choice for the long-term treatment by 82% of the respondents, of whom 60% used full therapeutic doses and 40% chose a dose reduction. When continuing anticoagulants after the long-term treatment period, 44% of respondents preferred LMWH, 10% VKA, while the remaining 45% chose per individual patient for either LMWH or VKA. In conclusion, we observed a relatively high observance rate of the guidelines with respect to the use of LMWH for the long-term treatment of VTE in cancer. In contrast, the dose of LMWH and the type of anticoagulant chosen after the initial 3–12 months varied substantially, probably reflecting the limited available evidence.

Alteration of pharmacokinetics of lepirudin caused by anti-lepirudin antibodies occurring after long-term subcutaneous treatment in a patient with recurrent VTE due to Behcet’s disease

VASA ◽  
2010 ◽  
Vol 39 (1) ◽  
pp. 103-107 ◽  
Author(s):  
Linnemann ◽  
Greinacher ◽  
Lindhoff-Last
Keyword(s):  
Anticoagulant Therapy ◽  
Plasma Levels ◽  
High Titer ◽  
Vitamin K Antagonists ◽  
Term Treatment ◽  
Bleeding Complications ◽  
Thrombin Inhibitor ◽  
Long Term Treatment ◽  
Recurrent Vte

The direct thrombin inhibitor lepirudin is mainly applied in heparin-induced thrombocytopenia. We report here the case of a 37-year-old kurdish woman in whom Behcet’s disease was diagnosed in 1998 when she presented with a Budd Chiari syndrome (BCS) complicated by pulmonary embolism. Recurrent venous thromboembolism (VTE) occurred despite anticoagulant therapy with UFH, LMWH or phenprocoumon and various immunosuppressive therapy regimens. In 2001, when BCS recurred ultimately i.v. lepirudin was administered. When the patient improved and remained clinically stable lepirudin was applied subcutaneously. During long-term treatment with twice-daily 50 mg no further VTE was observed over the following years. Additionally, no bleeding complications occurred. In May 2005 anticoagulant therapy was switched to phenprocoumon. BCS reoccurred when INR values were suboptimal in February 2007, and lepirudin treatment was immediately restarted. After admission the patient received 50 mg b.i.d. lepirudin s.c. with plasma levels in the therapeutic range (0.5-1.0 mg / l). Over the following months, lepirudin levels repeatedly exceeded the upper limit of this range and the dosage was stepwise reduced. Finally, 20 mg b.i.d. were sufficient to obtain therapeutic levels. Renal function was normal, but lepirudin antibodies were present in high titer, as assessed by ELISA. We suppose that these antibodies reduce renal filtration of lepirudin thus leading to increased plasma levels. This case is an example for successful long-term therapeutic-dose anticoagulation with s.c. lepirudin in a patient with Behcet’s disease and recurrent VTE despite therapeutic anticoagulant therapy with LMWH or vitamin K antagonists. However, frequent measurement of lepirudin plasma levels is needed. If stepwise dose lowering is required over time, the presence of lepirudin antibodies should be considered.

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