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Test Code RIVA Rivaroxaban Level by Anti-Xa

Specimen Type

Plasma

Container/Tube

Light blue top tube, 3.2% sodium citrate

Offsite Collection Instructions

The blood sample should be ordinarily collected 2 to 3 hours
following administration of rivaroxaban, since this is the
usual time required to reach peak plasma levels.

 

Whole blood sample must arrive in the laboratory within
three hours of specimen collection.

 

If transport time exceeds three hours, follow centrifugation
instructions:

  • Samples must be centrifuged at >2500 x g for 10 minutes
    at room temperature.
  • Carefully remove the plasma from the cells using a plastic
    transfer pipette avoiding the buffy coat.
  • Aliquot removed plasma into 2 plastic tubes containing a
    minimum of 500 uL of specimen in each tube.
  • The plasma samples must then be frozen at -20 C.
  • Once solidly frozen, they must be shipped on dry ice.
    Samples that have thawed in transit will be rejected.

Note: For clients who do not have access to dry ice DO NOT
freeze the specimen. Follow the centrifugation instructions and
send fresh plasma or send whole blood sample. It now becomes
vital that the specimen arrives in the lab within three hours of
collection.

Turnaround Time

8 hours

Preferred Volume

1 mL

UCMC Collection Instructions

The blood sample should be ordinarily collected 2 to 3
hours following administration of rivaroxaban, since this is
the usual time required to reach peak plasma levels.

 

Additional Information

Rivaroxaban is monitored by a functional anti-Xa
assay.

Peak steady-state plasma concentrations are typically
reached approximately 2 to 3 hours following oral
administration. Rivaroxaban peak concentrations of 160-360
ng/mL and trough concentrations of 4.3-95.7 ng/mL have been
reported in patients taking rivaroxaban 20 mg once daily
(Thromb Haemost 2008; 100:453-461); however, actual target goals depend
upon intended anticoagulation intensity and dosing schedules
for the individual patient.

This test was validated by the University of Chicago
Medicine Coagulation Laboratory. This test has not been cleared or
approved by the FDA. The laboratory is regulated under CLIA as
qualified to perform high-complexity testing.

 

Fee Code

30280299

Synonyms

Xarelto
Anti-Xa

Test Usage

Monitoring of rivaroxaban (Xarelto)

STAT Turnaround Time

n/a

Specimen Minimum Volume

0.5

DAY(S) AND TIME(S) PERFORMED

Testing is performed 7 days a week from 8:00 am to 11:0 pm.
Samples that arrive after 11:00 pm will be frozen and run the
following day.

STAT DAY(S) AND TIME(S) PERFORMED

Not Available

CPT

80299

Method Name

Chromogenic

Reject Due To

Specimens that have wrong ratio of blood to anticoagulant
(fill volume) clotted or grossly hemolyzed.