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Ethosuximide, Serum or Plasma
2010358
Ordering Recommendation

Optimize drug therapy and monitor patient adherence.

Mnemonic
ETHOSUX
Methodology
Quantitative Enzyme Immunoassay
Performed
Sun-Sat
Reported
1-5 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
Timing of specimen collection: Pre-dose (trough) draw - At steady state concentration. 
Collect
Plain Red. Also acceptable: Lavender (K2or K3EDTA) or Pink (K2EDTA). 
Specimen Preparation
Separate serum or plasma from cells ASAP or within 2 hours of collection. Transfer 1 mL serum or plasma to an ARUP Standard Transport Tube. (Min: 0.5 mL) 
Storage/Transport Temperature
Refrigerated. 
Unacceptable Conditions
Whole blood. Gel separator tubes, light blue (citrate), or yellow (SPS or ACD solution). 
Remarks
 
Stability
After separation from cells: Ambient: 5 days; Refrigerated: 1 week; Frozen: 2 months 
Reference Interval
Test Number
Components
Reference Interval
 EthosuximideTherapeutic: 40-100 µg/mL
Toxic: > 150 µg/mL

Interpretive Data
The therapeutic range is based on serum pre-dose (trough) draw at steady-state concentration. Toxic concentrations may cause dizziness, drowsiness and anorexia. The incidence of adverse reactions is low; however, life-threatening agranulocytosis and fatal pancytopenia have been reported.

Note
Hotline History
View Hotline History
Components
Component Test Code*Component Chart NameLOINC
0090415Ethosuximide3616-0
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • Zarontin