Test Directory

Test Code
FRVA
Test Name
Valproic Acid, Free
CPT Codes
80165
Expected Turnaround Time
Same day
Clinical Utility
The Valproic acid that circulates in blood is 85-90% protein bound under normal circumstances. Since neurologic activity and toxicity of valproic acid are directly related to the unbound fraction of the drug, measurement of the free or unbound drug may be necessary where altered protein binding is possible, such as in hypoalbuminemia, pregnancy, renal or hepatic failure, the elderly or use of concomitant drug therapy.
Specimen and Container Info

Specimen

Container

Volume

Serum

Red Top, Plain

3 mL

Plasma

Dark Green Top (Lithium Heparin) 

3 mL

Plasma

Lavender Top (EDTA) 

3 mL

Processing and Submission Instructions
  1. Centrifuge specimens for 5 minutes at 3000 rpm.
  2. Transfer serum or plasma to a plastic aliquot tube.
Transport Instructions

Transport to the laboratory refrigerated. 

Stability Requirements

Frozen

 1 year

Causes for Rejection
  • Specimens collected in separator tubes will be rejected.
  • Serum/Plasma volumes less than 1 mL will be rejected.  
Methodology
Enzyme Immunoassay (EIA)
Reference Intervals

Age

Reference Interval

Units

All Ages

4.0 - 15.0

µg/mL 

 

Critical Values

Age

Critical Value

Units

All Ages

>= 20

µg/mL 

Performing Location
Roble Road Core Laboratory
Alternate Names
  • Depakene
  • Depakote
  • Valproate
Testing Schedule
Routine daily, STAT testing available