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HelpTest ID MEX Mexiletine, Serum
Useful For
Assessing achievement of optimal therapeutic concentrations
Assessing potential toxicity
Method Name
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
Mexiletine, SSpecimen Type
Serum RedSpecimen Required
Patient Preparation: Samples should only be collected after patient has been receiving mexiletine for at least 3 days. Trough concentrations should be collected just before administration of the next dose.
Collection Container/Tube: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1.5 mL
Collection Instructions:
1. Samples should only be collected after patient has been receiving mexiletine for at least 3 days.
2. Draw blood immediately before next scheduled dose.
3. Centrifuge within 2 hours of draw and aliquot to remove serum from spun RBCs.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum Red | Refrigerated (preferred) | 28 days | |
| Ambient | 28 days | ||
| Frozen | 28 days |
Reference Values
Trough Value
0.5-2.0 mcg/mL: Therapeutic concentration
>2.0 mcg/mL: Toxic concentration
Day(s) Performed
Monday through Saturday
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
80299
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| MEX | Mexiletine, S | 40779-1 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 9245 | Mexiletine, S | 40779-1 |
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.Forms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.