Last Modified:
1/4/2023 5:37:06 AM
Medical Necessity Documentation:
Client Notes:
Patient Preparation:
Specimen Requirements:
1.0 mL Serum from a Red Top Tube in a Plastic Vial
Collection Instructions:
Minimum Volume:
0.5 mL Serum
Transport & Storage: Temperature/Stability:
5 days Ambient - Transport
14 days Refrigerated
30 days Frozen
Rejection Criteria:
Serum Separator Tube (SST or PST) • Gel
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.
Critical Ranges:
Test Comments:
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
Documentation:
Custom Panel:
No
PRODUCTION SCHEDULE
Turn Around Time:
3 to 5 days
Days Performed:
Tuesday, Thursday, Saturday
Sites Performed:
Quest - Chantilly to Valencia
PHL Test Code:
MSOT
EPIC Test Code:
Send Out Test Code:
18865
Alternate Test Names:
Leflunomide Level
Included Tests:
CPT Coding:
80193
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