Test Overview
Test Methodology
Gas Chromatography (GC)
Test Usage
Monitor therapeutic drug levels
Reference Range *
40-100 mcg/mL, Toxic > 150 mcg/mL.
* Reference ranges may change over time. Please refer to the original patient report when evaluating results.
Test Details
Days Set Up
Daily
Analytic Time
4 hours
Soft Order Code
ESXD
MiChart Code
Ethosuximide Level
Synonyms
- Zarontin
- ESXD
- ETHOSUXIMIDE
- ETHOSUXIMIDE LEVEL
Laboratory
Chemical Pathology
Section
Drug Analysis
Specimen Requirements
Collection Instructions
Collect blood in a red top tube; do not use SST tube. Centrifuge, aliquot serum into a plastic vial, and refrigerate. Heparinized or EDTA plasma is also acceptable.
Alternate Specimen
Green top (sodium heparin), Lavender top (EDTA). [11/09]
Normal Volume
0.5 mL serum
Minimum Volume
0.25 mL serum
Rejection Criteria
SST tube not acceptable.
Additional Information
Ethosuximide levels fluctuate little from day to day with regular medication intake. Timing of samples is not critical. Half-life is 30 hours for children and 60 hours for adults.
Billing
CPT Code
80168
Fee Code
33232
LOINC
3616-0