Test Code MEX Mexiletine, Serum
Reporting Name
Mexiletine, SUseful For
Assessing achievement of optimal therapeutic mexiletine concentrations
Assessing potential mexiletine toxicity
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Performing Laboratory
Mayo Clinic Laboratories in RochesterSpecimen Type
Serum RedSpecimen Required
Patient Preparation: Specimens 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.
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube: Red top (serum gel/SST are not acceptable)
Submission Container/Tube: Plastic vial
Specimen Volume: 1.5 mL
Collection Instructions:
1. Draw blood immediately before next scheduled dose.
2. Centrifuge and aliquot serum into a plastic vial within 2 hours of collection.
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 |
Reject Due To
Gross hemolysis | OK |
Gross lipemia | OK |
Gross icterus | OK |
Reference Values
Trough Value
0.5-2.0 mcg/mL: Therapeutic concentration
>2.0 mcg/mL: Toxic concentration
Day(s) Performed
Monday through Friday
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. It has not been cleared or approved by the US Food and Drug Administration.Report Available
2 to 5 daysForms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.