Test Overview
Test Methodology

Gas Chromatography (GC)

Test Usage

Monitor therapeutic drug levels

Reference Range *

40-100 mcg/mL, Toxic > 150 mcg/mL.

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]
Rejection Criteria
SST tube not acceptable.
Yellow Top Tube
Red Top Tube
Normal Volume
0.5 mL serum
Minimum Volume
0.25 mL serum
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
NY State Approved
No