Test Overview
Test Methodology

High Performance Liquid Chromatography (HPLC)

Test Usage

Therapeutic drug monitoring of Mercaptopurine (6-MP) (Purinethol) or Azathioprine (Imuran) (measured as 6-Mercaptopurine).

Reference Range *

Therapeutic and toxic ranges have not been established. Usual therapeutic doses of either mercaptopurine or azathioprine produce 6-mercaptopurine serum concentrations of less than 1000 ng/mL.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Details
Days Set Up
Daily
Analytic Time

5 - 11 days

Soft Order Code
FMERC
MiChart Code
Mercaptopurine (Imuran), Level
Synonyms
  • Purinethol
  • Thiopurines
  • Imuran
  • Azathiopurine
  • 6 Mercaptopurine (6 MP)
  • Mercaptopurine (6-MP) Level
  • MERCAP
  • 6MP
Laboratory
Sendout
Reference Laboratory
Mayo FMERC (91120) (MedTox 368)
Section
Special Testing
Specimen Requirements
Collection Instructions

Collect specimen in a red top or green top tube; do not use SST tube. Centrifuge, aliquot serum or plasma into a plastic vial and refrigerate.

Rejection Criteria
SST or PST tube not acceptable.
Yellow Top Tube
Red Top Tube
Normal Volume
2 mL serum or plasma
Minimum Volume
0.3 mL serum or plasma
Additional Information

Mercaptopurine may be administered as an antineoplastic or may be present as a metabolite of the immunosuppressant drug azathioprine. Test sent to Mayo Medical Laboratories; performed by MedTox Laboratories.

Billing
CPT Code
80375
Fee Code
32152
LOINC
11242-5
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