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Test Code
METX
Test Name
Methotrexate
CPT Codes
80204
Expected Turnaround Time
Same day
Clinical Utility
Useful for following therapy to assess drug clearance and potential toxicity.
Specimen and Container Info

Specimen

Container

Volume

Serum

Red Top, Plain*

1 mL

Plasma

Dark Green Top (Lithium Heparin) 

1 mL

Plasma

Gray Top (Sodium Fluoride, Potassium Oxalate) 

1 mL

Plasma

Lavender Top (EDTA) 

1 mL

*Preferred Specimen 
Collection Instructions

Collection time is determined by dosing protocol.
Processing and Submission Instructions

Protect specimen from light by:

  • Aliquoting into a brown colored tube.
  • Wrapping the collection tube or aliquot in aluminum foil.
  • Transporting the specimen in a brown paper bag.
Transport Instructions

Transport to the laboratory refrigerated. 
Causes for Rejection
  • Specimens collected in separator tubes will be rejected.  
  • Specimens unprotected from light for >2 days will be rejected.
Methodology
Enzyme Immunoassay (EIA)
Reference Intervals

Therapeutic range is dependent on dosage.
Critical Values

Potentially Toxic:

  • > 5.0 umol/L 24 hours after high dose therapy.
  • >0.5 umol/L 48 hours after high dose therapy.
Performing Location
Roble Road Core Laboratory
Alternate Names
  • MTX
  • Trexall
  • Xatmep
Testing Schedule
Routine daily, STAT testing available
The American Medical Association (AMA) Current Procedural Terminology (CPT) codes published by HNL Lab Medicine are guidelines and are intended for informational purposes only. CPT coding is the exclusive responsibility of the billing entity. View the Terms.
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