Test directory: Methotrexate

Ordering Code751
Test NameMethotrexate
AliasMexate
Preferred SpecimenSerum
Preferred ContainerPlain (Red)
Collection InstructionsClot red top tube for 45 minutes, aliquot & foil aliquot tube immediately to protect from light
Refrigerate specimen within 4 hours of collection.
Handling InstructionsCentrifuge to separate within 1 hour of collection. Aliquot and foil aliquot tube immediately to protect from light
Refrigerate specimen within 4 hours of collection.
Transport RequirementsOahu: Refrigerated
Airline: Frozen
Specimen StabilityAmbient: 4 Hours
Refrigerated: 2 Weeks
Frozen: Indefinite
Rejection CriteriaSpecimen older than stability limits, Grossly hemolyzed,
Not protected from light, SST tube
Avail. StatNO
Analytic Time1 Day
MethodologyEnzyme Immunoassay (EIA)
Reference Lab Clinical Labs of Hawaii - KMCWC

Reference range(s)

ComponentAgeMale NormMale Critical LowMale Critical HighFemale NormFemale Critical HighFemale Critical LowUnitsAdd'l info
MethotrexateALLuM/LSee report.
Methotrexate, ExpALLM/L

Interpretation...

Interpretation:
No precise relationship between methotrexate serum levels and antineoplastic efficacy has been established, although levels below approximately 0.02 uM/L were seen as necessary for resumption of DNA synthesis

Critical methotrexate levels vary depending upon the dose delivered and the length of infusion. Consult individual treatment protocols to determine if hydration or leucovorin rescue should be changed

Testing has been performed by
Clinical Laboratories of Hawaii
Kapiolani Medical Center 1319 Punahou Street
Honolulu, HI 96826
See report.