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Methsuximide/Normethsuximide

Celontin, ARUP: 3000251, SOFT: XAMSX, EPIC: LAB7145

Specimen Collection Criteria

Collect (preferred specimen): One plain Red-top tube.
Also acceptable: One Lavender-top EDTA tube.

Do not use Serum Separator Tubes.
Time of Collection: Trough, just prior to the next dose.

Physician Office/Draw Specimen Preparation

Centrifuge to separate serum or plasma from cells within two hours of collection. Transfer serum or plasma to a plastic transport tube and refrigerate (2-8°C or 36-46°F).

Preparation for Courier Transport

Transport: 1.0 mL serum or plasma, refrigerated (2-8°C or 36-46°F). (Minimum: 0.3 mL)

Rejection Criteria

Serum Separator (SST) tubes.

Specimens not collected or processed as indicated.

In-Lab Processing

Centrifuge to separate serum or plasma from cells within two hours of collection. Transfer serum or plasma to a plastic transport tube and refrigerate (2-8°C or 36-46°F).

Transport: 1.0 mL serum or plasma, refrigerated (2-8°C or 36-46°F). (Minimum: 0.3 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 7 days
Refrigerated (2-8°C or 36-46°F): 14 days
Frozen (-20°C/-4°F or below): 14 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to ARUP Laboratories, Salt Lake City, UT, forwarded to NMS, Willow Grove, PA.

Performed

Varies.
Results available the 4-11 days.

Reference Range

By Report.

Test Methodology

High Performance Liquid Chomatography / Tandem Mass Spectrometry.

Interpretation

By report.

Clinical Utility

Methsuximide is an anticonvulsant indicated for the control of absence (petit mal) seizures that are refractory to other drugs. The methsuximide assay is used to optimize dosage, monitor compliance, and assess toxicity. Normethsuximide is an active metabolite of methsuximide.

CPT Codes

80339, (AH G0480).

Contacts

Last Updated

4/10/2021