Anticoagulant Therapy

Diagnostic Equity Question: INR is 3.9

This question appeared 2-24-26 on the Diagnostic Equity website: “I’m on warfarin for atrial fibrillation, and my INR today is 3.9. The target range is 2.0–3.0. I haven’t changed my diet or missed any doses. What factors could cause my INR to drift this high unexpectedly, and when does an elevated INR become an emergency?” […]

Anticoagulant Therapy

CAP Today: Hemostasis Testing While on DOACs

This open-access January 26 CAP Today document features the opinions of several experts as they address the limitations of coagulation testing in patients taking DOACs, such as dabigatran, rivaroxaban, or apixaban, and speculates on the coagulation effects of the upcoming anti-XI antithrombotics: Direct Oral Anticoagulants–New Guidance, Lab Testing.

Anticoagulant Therapy

A History of Russell Viper Venom

Here’s an amusing history of RVV and Dr. Russell, who named the venom. You may retrieve the article from your medical library. Thachil J. Russell viper venom: a journey from the bedside to the bench and back to the bedside. Semin Thromb Hemost. 2024;50:115-118. doi: 10.1055/s-0043-1771269. PMID: 37506733. Abstract Russell Viper Venom (RVV) is widely […]

Anticoagulant Therapy

What is the MRX PT DOAC Assay?

Thanks to Ali Sadeghi-Khomami, PhD, Precision BioLogic Inc., for a heads-up describing the MRX PT DOAC assay, offered by Nordic Biomarker, Umeå and Linköping, Sweden. For details about the assay, obtain this article from your medical library: Salter B, Moffat K, Carlino S, et al. Evaluation of the MRX PT DOAC assay for detection of clinically […]

Anticoagulant Therapy

February 2026 QQ: DOACs

Our February 2026 Quick Question is a quiz that asks, “Which DOAC is a direct thrombin inhibitor?” Since 2010, DOACs have become our primary antithrombotic agents prescribed for prophylaxis or therapy. While more DOACs are on the horizon, the current anticoagulants directly inhibit either thrombin or FXa. Please make your selection in the right-hand column […]

Quick Question Archive

World Thrombosis Day Article: Renal Vein Thrombosis

Click here for a World Thrombosis Day article about Renal Vein Thrombosis. Introduction Renal vein thrombosis is a blood clot that occurs in the veins draining blood from the kidneys. A blood clot in the renal vein will impact kidney function because it slows the flow of blood from the kidney and can reduce the […]

Anticoagulant Therapy

The Value of Offering DOAC Measurements

Obtain this article from your medical library: Swan D, Roberts L, Thachil J. In a nutshell: testing DOAC levels-when, why and what it means? Br J Haematol. 2026. doi: 10.1111/bjh.70313. PMID: 41482473. Abstract Plasma direct oral anticoagulant (DOAC) levels are not routinely required for the majority of patients; however, they may provide valuable information in […]

Anticoagulant Therapy

Cohort Study: Do Anticonvulsants Interfere with DOAC Therapy?

Navigate to this open-access population cohort study of the effects of anticonvulsants when used during DOAC Rx: Carlin S, Holbrook AM, Candeloro M, et al. Association of direct oral anticoagulant-anticonvulsant coprescription with clinical outcomes in older adults: a population-based cohort study. J Thromb Haemost. 2025:S1538-7836(25)00727-5. doi: 10.1016/j.jtha.2025.10.027. PMID: 41207565. Abstract Background: Anticonvulsants vary in their […]

Anticoagulant Therapy

Anticoagulation Forum Archived Webinars

Fifth on our alphabetical Hemostasis Agencies list is the Anticoagulation Forum. The forum offers a lengthy list of archived educational webinars that describe a number of antithrombotic therapy issues. Click here for the forum’s webinar selection.

Anticoagulant Therapy

Andexanet Alfa Withdrawn from the US Market

Thanks for the heads-up from Dr. Paul Riley, who commented on our December 27, 2025, post, Clinical Research Study: Andexanet Alfa for Enoxaparin Reversal. Here is the press release from AstraZeneca announcing the withdrawal of andexanet alfa from the US market.

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George Fritsma is a medical laboratory scientist, educator, and author. George is a member of the International Society on Thrombosis and Hemostasis, the International Society for Laboratory Hematology, and the American Society for Clinical Laboratory Science.

Cheat Sheets from George

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