The 2018 European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation [Extracts]

NOAC & INDICATIONS

NOAC & contraindications

SWITCHING BETWEEN ANTICOAGULANTS

Vitamin K antagonist to non-vitamin K antagonist oral anticoagulant

The NOAC can immediately be initiated once the INR is <_2.0. If the INR is 2.0–2.5, NOACs can be started immediately or (better) the next day. For INR >2.5, the actual INR value and the half-life of the VKA need to be taken into account to estimate the time when the INR value will likely drop to below this threshold value [half-lives for acenocoumarol 8–24 h, warfarin 36–48 h, phenprocoumon 120–200 h (6 days)]. The proposed scheme (also shown in Figure 2, top panel) tries to unify different specifications from the SmPCs, which state that NOAC can be started when INR is ≤3 for rivaroxaban, ≤2.5 for edoxaban, and ≤2 for apixaban and dabigatran.

Non-vitamin K antagonist oral anticoagulant (NOAC) and Vitamin K antagonist (VKA)

Because of the slow onset of action of VKAs, it may take 5–10 days before the INR is in the therapeutic range, with large individual variations (see also chapter 20). Therefore, the NOAC and VKA should be administered concomitantly until the INR is in a range that is considered appropriate (Figure 2, lower panel)—similar to the situation when low molecular weight heparins (LMWHs) are administered during VKA initiation. A loading dose is not recommended for acenocoumarol and warfarin, but is appropriate with phenprocoumon (see chapter 20).

As NOACs may have an impact on INR measurements, it is important that the INR (i) is measured just before the next intake of the NOAC during concomitant administration and (ii) is re-measured early after stopping the NOAC (i.e. reflecting solely VKA therapy) to assure adequate anticoagulation. It is also recommended to closely monitor INRs within the first month until stable values have been attained (i.e. three consecutive measurements yielded values between 2.0 and 3.0). At the end of the ENGAGE-AF trial, patients on edoxaban transitioning to VKA received up to 14 days of a half dose of the NOAC until the INR was within range, in combination with the above intensive INR testing strategy.

The 2018 European Heart Rhythm Association Practical Guide on the ues of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation [ European Heart Journal (2018) 00, 1-64 ]

Dosing Guides for Apixaban in non-valvular AF: •      Generally use 5 mg BD •      Dose adjustment to 2.5 mg twice daily is recommended for patients with at least 2 of the following characteristics:            age ≥80 years   ;   body weight ≤60 kg   ;   serum creatinine ≥1.5 mg/dL or (≥ 133 mcmol/L)

NOAC & renal function

NOAC & HEPATIC FUNCTION

NOAC & LABORATORY COAGULATION PROFILE