Test Overview
Clinical Utility
Refer to BC Cancer Methotrexate Monograph and Cancer Care Ontario at external websites.
Method
Competitive binding enzyme immunoassay
Result Included
Methotrexate
Specimen
Specimen Type
Gel-separator tubes are not acceptableSerum
Plasma
Containers
Preferred Containers
Red Top (no additive)
Acceptable Containers
Green top (Na Heparin); Green top (Li Heparin); Lavender top (EDTA)
Volume
Sample Volume
1 mL
Minimum Volume
0.5 mL
Specimen Comment
<b>Avoid gel separator tubes.</b>
Collection & Handling
Collection Instructions
Collect at 24, 48 and 72 hrs following high I.V. dose.
Handling Information
Separate within 2 hours of collection. Specimen must be labelled inside and outside of the light protecting wrap. Store and submit specimen protected from light in an amber vial.
Additional Information
The sampling of Methotrexate is dependent on dose, duration of infusion and clinical status of the patient.
Stability
| Ambient | Refrigerated | Frozen |
|---|---|---|
| 2 days | 14 days | 1 month |
Rejection Criteria
| Criteria | Specification |
|---|---|
| Specimen | Not protected from light or collected with gel-separator |
Performance & Interpretation
Turnaround Time
2 days
Results
Name
Units
Reference Range
Conversion
-
Methotrexateµmol/LPotential toxicity following high-dose methotrexate dosing:
24 hours: ≥ 10
48 hours: ≥ 1
72 hours: > 0.1
Comment
Refer to BC Cancer Methotrexate Monograph and Cancer Care Ontario at external websites.
Referral Location
Canada
Interface & Setup
HL7 Interface Codes
| Order Code | Result Name | Result Codes | Units |
|---|---|---|---|
| METHO | Methotrexate | 3163 | umol/L |
Test Version
Last Updated
2023-09-18