Mexiletine, Serum or Plasma

TEST: 716076
Test number copied
CPT: 80299
Updated on 11/13/2024
Print Share

Expected Turnaround Time

3 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

2 - 4 days

3 days

Related Documents

Specimen Requirements

Specimen

Serum or plasma

Volume

1 mL

3 mL

1 mL

Minimum Volume

0.2 mL

Container

Red-top (no additive) tube or green-top (heparin) tube; gel-barrier tubes are not recommended

Red-top tube, lavender-top (EDTA) tube, or green-top (heparin) tube. Do not use a gel-barrier tube. The use of gel-barrier tubes is not recommended due to slow absorption of the drug by the gel. Depending on the specimen volume and storage time, the decrease in drug level due to absorption may be clinically significant.
Red-top (no additive) tube or green-top (heparin) tube; gel-barrier tubes are not recommended

Collection

Transfer separated serum or plasma to a plastic transport tube. Trough levels are most reproducible.

Transfer separated serum or plasma to a plastic transport tube.e.

Transfer separated serum or plasma to a plastic transport tube. Trough levels are most reproducible.

Storage Instructions

Submission/transport (<3 days): Room temperature. For storage beyond three days, specimen should be refrigerated or frozen.

Room temperature

Submission/transport (<3 days): Room temperature. For storage beyond three days, specimen should be refrigerated or frozen.

Stability Requirements

TemperaturePeriod
Room temperature7 days
Refrigerated14 days
Frozen14 days
Freeze/thaw cyclesStable x3

Test Details

Use

This test is used for therapeutic drug management.

This Class 1B drug is used to suppress premature ventricular arrhythmias and may be as effective as quinidine or procainamide for this purpose. Mexiletine is less effective in patients with recurrent refractory ventricular tachycardia and fibrillation, and extracardiac side effects may limit its long-term usefulness. Approximately 45% of all patients experience side effects within the commonly accepted therapeutic range of 0.5−2.0 μg/mL.1 Concurrent administration of a Class 1A antiarrhythmic drug (eg, quinidine, disopyramide) or propranolol may provide better control of the arrhythmia and permit a reduction in the dose of mexiletine, thus reducing side effects. Supraventricular arrhythmias are not controlled by mexiletine.

This test is used for therapeutic drug management.

Limitations

This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.

This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.

This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.

Methodology

Liquid chromatography/tandem mass spectrometry (LC/MS-MS)

High-pressure liquid chromatography (HPLC)

Liquid chromatography/tandem mass spectrometry (LC/MS-MS)

Reference Interval

500–2000 ng/mL

Therapeutic: 0.75−2.00 μg/mL

500–2000 ng/mL

LOINC® Map

For Providers

Please login to order a test

Order a Test

© 2021 Laboratory Corporation of America® Holdings and Lexi-Comp Inc. All Rights Reserved.

CPT Statement/Profile Statement

The LOINC® codes are copyright © 1994-2021, Regenstrief Institute, Inc. and the Logical Observation Identifiers Names and Codes (LOINC) Committee. Permission is granted in perpetuity, without payment of license fees or royalties, to use, copy, or distribute the LOINC® codes for any commercial or non-commercial purpose, subject to the terms under the license agreement found at https://loinc.org/license/. Additional information regarding LOINC® codes can be found at LOINC.org, including the LOINC Manual, which can be downloaded at LOINC.org/downloads/files/LOINCManual.pdf