Specimen

Serum or Plasma

Collection Medium:

Alternate
Collection Media:

Lavender top tube (EDTA)

Minimum:

1.0 mL serum from red top tube or 1 mL EDTA plasma

Analytic Time:

1 week

Reference Range:

By report

Comments:

Reporting Limit;
Teriflunomide  5.0 ng/mL

Women who are being treated with Leflunomide and desire to become 
pregnant it is recommended that the plasma Teriflunomide levels be less 
than 20 ng/mL by two separate tests taken at least fourteen (14) days 
apart.  Mean steady state trough plasma concentrations of Teriflunomide 
from patients on daily regimens of 5, 10 or 25 mg of Leflunomide were 
8,800 18,000 and 63,000 ng/mL, respectively.

The minimum effective concentration is reported to be 13,000 ng/mL.

Methodology:

High Performance Liquid Chromatography/Mass Spectrometry (LC/MS)

CPT Code:

82542