Test Name: Ethosuximide
Health Link Test Code: XETHO
LIS Test Code: ESUX
CPT Code(s): 80168
Methodology: Gas Chromatography
Days Performed: Daily, dayshift.
In-Lab Turnaround Time: 1 day.
Collection Container: Red top
Collect specimen for trough level prior to next dose.
Collection Volume: 3 mL
Pediatric Collection Volume: 1 mL
Sample Analyzed: Serum
Testing Volume: 1 mL
Pediatric Testing Volume: 0.4 mL
Centrifuge. Transfer cell-free serum to plastic vial. Refrigerate.
Transport specimen to laboratory. Transport with coolant pack if coming from clinic location.
Specimens collected in red cap with yellow ring (SST) tubes are not acceptable.
|Generally effective therapeutic concentration:|
|18 years and up:||40.0-100.0 mcg/mL|
Interpretation Type: Interpretive Guidelines
Critical Calls: yes
Result of "BELOW DETECTION" indicates that the result is below the method detection limit of 1 mcg/mL. The half-life is 40-60 hours in adults, 30-50 hours in children. Ethosuximide has been reported to cause elevation of serum phenytoin concentrations when two drugs are given concurrently. Concurrent therapy with valproic acid has been reported to cause elevations in ethosuximide concentrations.
This test was developed and its performance characteristics determined by the UWHC Clinical Laboratories. This test meets the standards for clinical testing. This test should not be regarded as investigational or for research use. The US Food and Drug Administration (FDA) has not approved or cleared this test; however, the FDA has determined that such clearance or approval is not necessary.