MEXILETINE

Test Documentation
Specimen Required
Draw blood in a plain red-top tube. Centrifuge, separate serum from cells within 2 hours and send 1.0 mL serum (0.5 mL minimum) refrigerated in a screw-capped plastic vial.
Submit with order: Mexiletine dose, Mexiletine dose frequency, Mexiletine route, Mexiletine type of draw.

Alternate Specimen
Plasma: EDTA

Rejection Criteria
Serum or plasma separator tubes, whole blood, citrated plasma or ACD plasma

Methodology
Quantitative Liquid Chromatography/Tandem Mass Spectrometry

Stability
Room Temperature: 2 days; Refrigerated: 5 days; Frozen: 2 months

Reference Range
Therapeutic:   1.0–2.0 µg/mL  
Toxic level:   >2.0 µg/mL  

Performed
Tuesday, Thursday, Saturday

Turnaround Time3-5 days
Test CodeMEX
CPT-4 Code (s)
80299
LOINC Codes
Mexiletine, Serum/Plasma   3819-0  
Mexiletine Dose   4332-3  

Warde
Medical
Laboratory