Conditions: Venous Thrombosis
Keywords: Rivaroxaban Xa-Factors Warfarin Thrombosis Embolism
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 96
Healthy volunteers: yes

Brief summary:
The study objective is to investigate the pharmacodynamics (effects of a drug product) when switching the treatment from warfarin to rivaroxaban.

84 young, healthy subjects will participate; they will be treated following a randomized, parallel-group (Treatments A, B, and C), placebo-controlled (Treatment B), and single-blind (Treatments A and B) design.

The first two groups (A, B) will receive warfarin for approximately one week to adjust their blood coagulation values to a specific level, i.e. to maintain an INR (international normalized ratio) of 2.0 - 3.0. This range is commonly used for long-term anticoagulant treatment.

The first group (A) will receive rivaroxaban for four days, the second group (B) will take placebo. On the last day, all subjects in groups A and B will receive vitamin K to neutralize the effects of warfarin. The third group (C) will not undergo prior treatment with warfarin but will receive rivaroxaban for four days.

Detailed description:

Arms:
arm 1: Days -6 and -5: 10 mg warfarin once daily or lower depending on international normalized ratio (INR); Days -4 to -1 (could be prolonged by two days): 2.5, 5, 10, 12.5 or 15 mg warfarin once daily depending on INR; Days 0 to 3: 20 mg rivaroxaban once daily; Day 5: 10 mg vitamin K once daily arm 2: Days -6 and -5: 10 mg warfarin once daily or lower depending on INR; Days -4 to -1 (could be prolonged by two days): 2.5, 5, 10, 12.5 or 15 mg warfarin once daily depending on INR; Days 0 to 3: 1 tablet matching placebo once daily; Day 5: 10 mg vitamin K once daily arm 3: Days 0 to 3: 20 mg rivaroxaban once daily

Interventions: intervention 1: Warfarin (Coumadin) intervention 2: Rivaroxaban (Xarelto, BAY59-7939) intervention 3: Placebo intervention 4: Vitamin K (Konakion)
Intervention descriptions: intervention 1: Days -6 and -5: 10 mg warfarin (Coumadin) once daily, dosage lower if the INR is already high on day -5; Days -4 to -1 (could be prolonged by two days): 2.5, 5, 10, 12.5 or 15 mg warfarin (Coumadin) once daily, dosage depending on INR intervention 2: Days 0 to 3: 20 mg rivaroxaban once daily intervention 3: Days 0 to 3: 1 tablet placebo, identical to active tablet intervention 4: Day 5: 10 mg vitamin K (Konakion) once daily

Protocol document: