3.2.2. Rivaroxaban

Rivaroxaban (Xarelto®) directly inhibits factor Xa. It selectively binds both free and prothrombin complex bound factor Xa and in this way inhibits thrombin and clot formation. Peak blood concentration is achieved after 1–3 h after drug ingestion. As much as 95% of the drug is bound to plasma protein. One-third of the drug is excreted through kidneys, the other two-thirds are metabolized in the liver. The drug half-life is 8–13 h [1, 24]. Therapeutic doses are 20 and 15 mg once daily for patients with atrial fibrillation [25]. Patients with VTE are treated with 15 mg twice daily for the first 3 weeks, followed by 20 mg once daily [26, 27]. The drug must always be ingested with food. The prophylactic dose for patients with total hip or knee replacement is 10 mg once daily [28, 29].

No laboratory monitoring of therapy is needed due to the predictive effect of the drug. Rivaroxaban prolongs PT; however, when an assessment of the drug blood level is needed, an anti-Xa test calibrated to rivaroxaban should be used [30].
