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HelpOrder Code LEFLU Leflunomide Metabolite (Teriflunomide), Serum
Reporting Name
Leflunomide Metabolite, SUseful For
Therapeutic monitoring of patients actively taking leflunomide
Assessment of elimination in patients requiring enhanced elimination of the drug
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Serum RedSpecimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. Draw blood no sooner than 12 hours (trough value) after last dose.
2. Within 2 hours of collection, centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
0.3 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum Red | Ambient (preferred) | 28 days | |
| Frozen | 28 days | ||
| Refrigerated | 28 days |
Reference Values
Therapeutic: >40 mcg/mL
Elimination: <0.020 mcg/mL
Day(s) Performed
Monday, Wednesday, Friday
CPT Code Information
80193
Method Description
Serum samples are diluted in an aqueous solution containing deuterated teriflunomide as an internal standard. This is injected onto a liquid chromatography system with Cohesive turboflow to separate the drug from serum components and analyzed by negative-ion mode tandem mass spectrometry.(Unpublished Mayo method)
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
| Gross icterus | OK |
Method Name
High-Turbulence Liquid Chromatography Mass Spectrometry (HTLC-MS/MS)
Forms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.