How and when to measure anticoagulant effects of direct oral anticoagulants? Practical issues.

Direct oral anticoagulants (DOACs) do not require dose adjustment based on laboratory testing. However, it might be necessary to measure their plasma concentrations in the following specific situations: 1) before thrombolytic therapy in patients with stroke; 2) before surgery or invasive procedure; 3) in case of adverse events (thrombosis or hemorrhage); 4) when immediate reversal of anticoagulation is needed; 5) in patients with extreme body weight; 6) when administering additional drugs potentially interfering with DOACs; and 7) when overdosage is suspected regardless of concomitant bleeding. Basic coagulation tests, such as prothrombin and activated partial thromboplastin time, should not be used as standalone tests to assess the levels of anticoagulation as they are not specific for DOACs and their results are dependent on the type of reagent used for testing.

Harmful and Beneficial Effects of Anticoagulants in Patients With Cirrhosis and Portal Vein Thrombosis.

Background & Aims: Vitamin K antagonists (VKAs) promote recanalization of portal vein thrombosis (PVT) in patients with cirrhosis. However, the benefit of PVT recanalization might be offset by major and minor bleeding associated with use of anticoagulants. We evaluated harmful and beneficial effects of VKA in patients with PVT and cirrhosis.

Coagulation parameters in patients with cirrhosis and portal vein thrombosis treated sequentially with low molecular weight heparin and vitamin K antagonists.

Background/aims: Information on coagulation for cirrhotics on anticoagulants is scanty. We investigated plasma from 23 cirrhotics treated with low-molecular-weight-heparin (LMWH) followed by vitamin K antagonists (VKA).

Methods: On days 1-4 patients received full-dose LMWH.

Vitamin K antagonists in children with central venous catheter on chronic haemodialysis: a pilot study.

Background: To date, no study has investigated the use of vitamin K antagonists (VKA) in children undergoing chronic haemodialysis (HD) with a central venous catheter (CVC).

Methods: Consecutive patients aged <18 years with a newly placed tunnelled CVC for chronic HD were enrolled over a 3-year period. Children with active nephrotic syndrome or a history of venous thrombosis received warfarin (VKA group) with therapeutic target international normalised ratios of between 2.

Biological variation of INR in stable patients on long-term anticoagulation with warfarin.

Within-individual biological variation of INR (CV(B)) was assessed in 245 selected stable warfarin-treated patients monitored by three thrombosis centers. Selection criteria were: treatment period of six months or longer before the observation period; at least six consecutive INRs within the therapeutic range of 2.0 - 3.