Anticoagulant Therapy

Check AT Before Starting Heparin?

George,would it be better to check the patient’s antithrombin III (AT III, antithrombin, AT) level before starting unfractionated heparin (UFH)? Regards, Frances Weekes. Hi, Frances, thanks for the question, and while I’d be happy to invite other opinions from our participants, I would not recommend screening for AT levels on everyone starting unfractionated heparin for the […]

Anticoagulant Therapy

Anticoagulants and Ketogenic Diet

From Maria Jose Lauria: I would like to know if you have any experience in patients with oral anticoagulants and ketogenic diet given to patient with seizures. Hello, and thank you for yet another fascinating question. I have no experience with anticoagulation in association with the ketogenic diet in seizure disorders. A literature search reveals a […]

Anticoagulant Therapy

Rivaroxaban Measurement by Anti-Xa

Dave McGlasson forwarded Samama MM, Contant G, Spiro TE, Perzborn E, Le Flem L, Guinet C, Gourmelin Y, Rohde G, Martinoli JL. Laboratory assessment of rivaroxaban: a review. Thromb J. 2013;11:11–18, linked below. The article supports measuring rivaroxaban with the chromogenic anti-Xa assay using rivaroxaban calibrators and controls, and concedes that the prothrombin time (PT) in […]

Anticoagulant Therapy

Change in Actin FS Sensitivity

Here is a new message from frequent contributor Joyce Low at St. Vincent’s in Sydney. “Our lab has been using Actin® FS since 2007. For us, different lot numbers have been reasonably similar in terms of the reference interval 25–35 s on Stago instruments and heparin therapeutic interval of 50–75 or 80s determined by anti-Xa assay. In […]

Anticoagulant Therapy

Does Lipitor Affect INR?

I received this August 6 note from Prof. Emeritus Bernadette Rodak, Indiana University Clinical Laboratory Science program. Prof. Rodak responds to questions posted by patients to the ASCLS Consumer Web Forum and passed this along for comment: “I have a question from a patient whose INR suddenly jumped to over 7 when he started atorvastatin (Lipitor®). I found […]

Anticoagulant Therapy

Kcentra or Profilnine?

From Jane Bossart: Any thoughts on whether Kcentra® (Behring CSL) will be better than Profilnine® (Grifols)? It seems there have been no head to head comparison yet. Hello, Jane, and thank you for your question. Although non-activated prothrombin complex concentrates (PCCs) and sometimes recombinant activated factor VII have been used off-label in conjunction with vitamin K […]

Anticoagulant Therapy

Does Riva Affect Thrombophilia Tests?

A message from Crystal Azevedo, Eastern Maine Healthcare System: Hello George, I was wondering if you or your colleagues are familiar with the interfering effects of rivaroxaban on tests for thrombophilia? I am testing a sample of plasma where the prescribed dose is 15 mg twice per day, and most of the test results are suspect. Thanks […]

Anticoagulant Therapy

POC Screening for Coumadin Effect

From John McClure: We have been approached by our neurology and ER services to establish point of care prothrombin time/international normalized ratio (PT/INR) testing to assess for Coumadin effect prior to initiating thrombolytic therapy in stroke patients. One of our point of care (POC) coordinators has pointed out that the devices are FDA approved for monitoring […]

Anticoagulant Therapy

In-house Dilute TT

Dear George, I greatly appreciate your website and congratulate you on have such a informative and open educational forum. I was wondering if it was possible to add “in-house dilute thrombin time” to the current Quick Question list? Thank you for your consideration. Sincerely, Glen Holloway. Hello, Glen, and thank you for your suggestion. I will […]

Anticoagulant Therapy

Transient Recurrent FVII Deficiency?

Another from Linda Stang, Alberta Health Service: We have a patient with ‘transient, recurrent’ factor VII deficiency that I suspect is drug related. When FVII is low, protein C and factor X are normal. Patient has been as high as 1.57 u/mL and as low as 0.08 u/mL. Do you or any of your participants have […]

Anticoagulant Therapy

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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.

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