Leflunomide as Metabolite Drug Level
| Label Mnemonic: | TERI |
| Epic code: | LAB3489 |
| Downtime form: | Doctor/Provider Orders - Pathology Core and Specialty Care Nursery |
Commercial Mailout Laboratory
6240-8 RCP
356-8593
6240-8 RCP
356-8593
Specimen(s):
Serum
Specimen
Instructions:
Draw blood no sooner than 12 hours (trough
value) after last dose.
Collection Medium:
 |
| Red top tube 5 mL (Clot Activator) |
Minimum:
Preferred Minimum: 1.0 mL serum from red top tube
Rejection Criteria:
Gross Hemolysis and Lipemia.
Delivery Instructions:
Deliver to laboratory immediately after collection.Turn Around
Time:
2-5 days upon receipt at reference laboratory
Reference Range:
Therapeutic: >40 mcg/mL
Elimination: <0.020 mcg/mL
Elimination: <0.020 mcg/mL
Interpretive Data:
Therapy: clinical targets for serum teriflunomide (leflunomide
metabolite) concentrations are still being determined, but levels >40
mcg/mL appear to correlate with better outcome.
Elimination: serum concentrations <0.020 mcg/mL (20 ng/mL) are preferred to minimize potential teratogenesis for patients considering pregnancy.
Elimination: serum concentrations <0.020 mcg/mL (20 ng/mL) are preferred to minimize potential teratogenesis for patients considering pregnancy.
Methodology:
High-Turbulence Liquid Chromatography Mass Spectrometry (HTLC-MS/MS)
CPT Code:
80193
Therapeutic monitoring of patients actively taking leflunomide
Assessment of elimination in patients requiring enhanced elimination of the drug