Treatment: direct oral anticoagulant (apixaban, rivaroxaban, dabigatran, edoxaban)

Cardiovascular · Treatment monitoring · updated 2026-10-31

BioMG follows French guidelines. Adapt it to the guidelines and the tests available where you practise.

Frequency: In 2025, 1 853 403 people were dispensed apixaban, 792 071 rivaroxaban and 89 950 dabigatran in community pharmacies (numbers per drug, not additive) ^[1].

Before starting a DOAC

Laboratory tests

Serum creatinine (calculate Cockcroft–Gault clearance using the current weight)
FBC (haemoglobin, platelets)
AST
ALT
Bilirubin
PT, aPTT (initial work-up of atrial fibrillation)if neededThe HAS guide on atrial fibrillation includes them in the diagnostic tests, before any anticoagulation ^[2]. They are not used to monitor the DOAC afterwards ^[3].
Weigh the patient on the day of the tests (essential to calculate clearance).

Detailed explanation and international comparison (in French): read it in English (machine translation)

Do not order

Plasma DOAC level (calibrated anti-Xa activity, diluted thrombin time) before starting or to adjust the dose: routine monitoring of concentrations is advised against ^[3,6]. No NABM procedure is dedicated to DOACs: the anti-Xa activity procedure targets heparin ^[12].

Long-term follow-up

At least once a year (more often depending on age and clearance: see the note)

Serum creatinine (recalculate Cockcroft–Gault clearance using the current weight)
FBC (haemoglobin)
AST
ALT

Detailed explanation and international comparison (in French): read it in English (machine translation)

Do not order

PT, aPTT or INR to monitor a DOAC: they do not correctly measure the anticoagulant effect or adherence ^[3], and variations at therapeutic doses are small and highly variable ^[5]. On dabigatran, INR is not reliable (falsely positive elevations) and must not be performed ^[4].
Routine plasma DOAC level: advised against; reserved for exceptional situations such as severe bleeding or urgent surgery ^[3,6].
Thrombophilia screen (protein C and S, antithrombin, activated protein C resistance, lupus anticoagulant) taken on a DOAC: DOACs distort these tests; if the tests are essential, sample at least 24 hours after the last dose (at least 48 hours for lupus anticoagulant, longer in renal failure) ^[3].

Intercurrent event (dehydration, infection, NSAID, new drug, bleeding)

Laboratory tests without waiting for the scheduled check

Serum creatinine (Cockcroft–Gault clearance)
FBC (if bleeding, pallor, unusual fatigue)if neededAn unexplained fall in haemoglobin prompts a search for bleeding ^[6]; haemoglobin helps detect occult bleeding ^[4].

Detailed explanation and international comparison (in French): read it in English (machine translation)

Switching from a VKA to a DOAC

After stopping the vitamin K antagonist, until the INR reaches the threshold for the chosen DOAC (see the note)

Detailed explanation and international comparison (in French): read it in English (machine translation)

Sources (15)