Test Overview
Test Methodology

High Performance Liquid Chromatography with Ultraviolet Detection (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)
  • 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.

Normal Volume
2 mL serum or plasma
Minimum Volume
0.3 mL serum or plasma
Rejection Criteria
SST or PST tube not acceptable.
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
80299
Fee Code
32152
LOINC
11242-5
NY State Approved
No