5417 - Rivaroxaban (anti-factor Xa)
- Citrate plasma 1:10, 1ml
LMW Heparin (low molecular-weight Heparin), unfractionated Heparin and the ‘new orally administered anticoagulants’ (NOACs, e.g. Fondaparinux, Rivaroxaban, etc.) have the effect of the preferred ‘Xa’ inhibitor factor because of their structure and molecular weight distribution. The dosage of such anticoagulants has to be adjusted to weight; laboratory checks are normally not necessary. Clinical indications for determining the ‘anti-factor Xa activity’ are: kidney insufficiency, pregnancy, long-term therapies, extreme bleeding- or thrombosis –hazard, or extreme over- or underweight, and in newborn babies and small children.
N.B.: Please always contact us by phone (under 071 844 4545), to ensure immediate sample collection; blood samples should preferably be taken in the morning . Blood samples should be taken 2 (-4) hours after the medication has been administered. For evaluation purposes, we need the data of the administered medication: please select the appropriate Profile Number accordingly.
There are no official reference values for Xarelto (Rivaroxaban). The only available expected values that can be given are from pharmacodynamic studies: with the administration of 10 mg Rivaroxaban, expected peak concentrations in patients with healthy kidneys are around 170 ng/ml (2 hours after dosing). Peak concentrations of 500 ng/ml appear to be overdosed; between 250 and 500 ng/ml, risk of bleeding increases. Concentrations of around 100 ng/ml appear to be sufficient for the prevention of thrombosis.