Mercaptopurine (6-MP, Purinethol)
Use
Mercaptopurine is commonly used as an antineoplastic or immunosuppressant drug. It is critical in treating leukemia and certain inflammatory conditions. As a metabolite of the immunosuppressant drug azathioprine, mercaptopurine serum levels can influence therapeutic outcomes. Determining these levels helps guide dosage adjustments to maximize therapeutic benefits while minimizing toxicity. Despite its wide use, therapeutic and toxic ranges are not firmly established, making steady monitoring essential for patient safety.
Special Instructions
This test requires precise specimen handling and transportation conditions to ensure accurate results. Refrigeration is preferred, and it's crucial to avoid gel tubes, which can interfere with the sample integrity. It is available for NY State clients, highlighting its broad accessibility for patient management.
Limitations
The test does not establish standard therapeutic or toxic levels of mercaptopurine, making clinical correlation crucial. Variations in plasma or serum levels can result from differing patient metabolism rates and concomitant medication use, which must be considered when interpreting results. Hemolysis, lipemia, and icterus conditions of specimens may affect test performance and accuracy.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 11242-5
- 11242-5
Result Turnaround Time
5-9 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
2 mL
Minimum Volume
0.3 mL
Container
plastic vial (no gel tube)
Collection Instructions
Draw blood in a green-top (sodium heparin) tube(s), plasma gel tube is not acceptable. Spin down and send 2 mL sodium heparin plasma refrigerated in a plastic vial.
Storage Instructions
Refrigerate specimen for up to 7 days, ambient for 72 hours, or freeze for 180 days.
Causes for Rejection
NA for hemolysis, lipemia, icterus, other
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 7 days |
| Frozen | 180 days |