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Methotrexate (MTX) Level, STAT

Mnemonic:    [NORDX MTX]
Name:    Methotrexate (MTX) Level, STAT
Specimen:    3 mL serum from a Red top tube. Do not use GEL barrier tubes.
Minimum Spec:    2 mL
Transport Temp:    Refrigerated
Ref Lab/Code:    NorDx MTX
  Method:    Fluorescence Polarization Immunoassay (FPIA)

A usual therapeutic range for MTX has not been defined. During high dose regimens, MTX may reach concentrations greater than 1000 umol/L.

Potentially toxic when MTX concentrations

-- Greater than 5.0 umol/L at 24 hours
-- Greater than 1.0 umol/L at 48 hours
-- Greater than 0.1 umol/L at 72 hours

Test performed at NorDx Laboratory.
Processing Info:    Test is built for NorDx but run at Maine Medical Center. Fill out a NorDx requisition, but send the sample to Maine Medical Center to be run STAT.

Call a courier if necessary. Put a note on the requisition to "Run STAT and call/FAX the report". Write our phone # 795-2330 and the fax # 795-2345 (the chemistry fax machine) on the requisition.

When the report is returned give it to a tech to enter in PathNet. Only the result number needs to be entered. The interpretive text and units of measure have been entered into PathNet.