Yale New Haven Hospital

Department of Laboratory Medicine
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Methotrexate level

Lab Section: 

Chemistry

 

Lab Location: 

Main Lab

Test ID: 

LAB481

 

Synonyms: 

MTX

Methodology: 

Enzymatic

Schedule: 

Run on request 1st and 2nd shift.

Reported: 

1 hour for STAT orders; 4 hours for Routine orders

Specimen Requirements: 

Collection: 3.0 mL Primary - Dark Green Top- Li-Heparin
Pediatric volume: 0.5 mL.
No gel barrier tube

 

Notes: 

Specify dose and time since dose.

Reference Interval: 

Measurement of methotrexate concentration within 48 hours of glucarpidase administration using this immunoassay is not reliable and can significantly overestimate the methotrexate concentration due to interference from metabolites.

 

Following administration of high-dose methotrexate, recommended ranges for blood levels are protocol-specific and generally depend on the total dose administered, infusion duration, and the timing of sample collection, all of which are included in this report. Additional biologic and clinical factors may need to be considered.  Refer to the relevant treatment protocol for interpretation of this result or, if consultation is required, please contact Pharmacy Services (203-688-2248) or Clinical Chemistry (203-688-2444).

CPT Code(s): 

80299

Last Changed: 

7/2/2018 3:17 PM

Last Reviewed: 

7/2/2018 3:17 PM