Leflunomide Metabolite

Overview

  • EPIC Code:
  • Soft Test Code:
  • MSOT
  • Send Out Test Code:
  • 18865
Alternate Names
  • Leflunomide Level
Clinical Significance

Leflunomide is an immunosuppressant medication used in the treatment of rheumatoid arthritis. Leflunomide is rapidly and extensively metabolized to teriflunomide, which is the active form of the medication. Steady state plasma concentrations in patients receiving recommended daily dosages: up to 63,000 ng/mL. It is recommended that all women of childbearing potential who discontinue leflunomide and women receiving treatment who wish to become pregnant undergo the cholestyramine drug elimination procedure. This procedure includes verification that plasma levels of teriflunomide are less than 20 ng/mL by two separate tests at least 14 days apart


Specimen Collection & Preparation

Specimen Requirements

1.0 mL Serum from a Red Top Tube in a Plastic Vial


Transport And Storage

5 days Ambient - Transport 
14 days Refrigerated
30 days Frozen


Collection Instructions

 


Minimum Volume

0.5 mL Serum


Neonatal Volume

Clinical Interpretation

Reference Range:

Mean steady state plasma concentrations of teriflunomide from patients on daily dosages of 5, 10, or 25 mg of leflunomide were 8,800, 18,000 and 63,000 ng/mL, respectively. It is recommended that women of childbearing potential who discontinue leflunomide therapy undergo the cholestyramine drug elimination procedure. This procedure includes verification that plasma levels of teriflunomide are less than 20 ng/mL by two separate tests at least 14 days apart.


Methodology:
  • Chromatography / Mass Spectrometry
Clinical Significance

Leflunomide is an immunosuppressant medication used in the treatment of rheumatoid arthritis. Leflunomide is rapidly and extensively metabolized to teriflunomide, which is the active form of the medication. Steady state plasma concentrations in patients receiving recommended daily dosages: up to 63,000 ng/mL. It is recommended that all women of childbearing potential who discontinue leflunomide and women receiving treatment who wish to become pregnant undergo the cholestyramine drug elimination procedure. This procedure includes verification that plasma levels of teriflunomide are less than 20 ng/mL by two separate tests at least 14 days apart


Production Schedule

Days Performed
Tuesday
Thursday
Saturday
Departments
  • Sendouts - Miscellaneous
Turn Around Time

3 to 5 days


Coding & Compliance

CDM

00913333


CPT Coding

80193