Valproic Acid, Free and Total
0099310
Ordering Recommendation
Submit With Order
Mnemonic
VPA-F
Methodology
Quantitative Enzyme Multiplied Immunoassay Technique
Performed
Tue-Sat
Reported
1-4 days
New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Timing of specimen collection: Pre-dose (trough) draw - At steady state concentration.  
Collect
Plain red.  
Specimen Preparation
Separate serum from cells within 2 hours of collection. Transfer 2 mL serum to an ARUP Standard Transport Tube. (Min: 1 mL)  
Storage/Transport Temperature
Refrigerated.  
Unacceptable Conditions
Light blue (citrate), gray (oxalate), green (heparin), K2EDTA plasma, tubes that contain liquid anticoagulant, or gel separator tubes.  
Remarks
 
Stability
After separation from cells: Ambient: 24 hours; Refrigerated: 1 week; Frozen: 4 months  
Reference Interval
Test Number Components Therapeutic Range
0099308 Valproic Acid, Total Therapeutic Range: 50-​125 µg/mL
Toxic: Greater than 150 µg/mL
0099309 Valproic Acid, Free Effective November 18, 2013
Therapeutic Range: 7-​23 µg/mL
Toxic: Greater than 30 µg/mL
0099791 Valproic Acid, Percent Free 5-​18 percent
Interpretive Data
Free valproic acid may be important to monitor in patients with altered or unpredictable protein binding capacity because valproic acid exhibits variable, dose-dependent protein binding. Valproic acid is also subject to drug-drug interactions due to displacement of protein binding. Calculating percent free attempts to minimize differences in test cross-reactivity and may be useful in dose optimization. Adverse effects may include headache, somnolence and dizziness.
Note
CPT Code(s)
80164
Components
Component Test Code*Component Chart Name
0099308Valproic Acid, Total
0099309Valproic Acid, Percent Free
0099791Valproic Acid, Free
* 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.
Cross References
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  • Depakote, Free
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  • Divalproex
  • Eplim
  • Free Valproate
  • Free Valproic Acid
  • Free VPA
  • Orlept
  • Protein Free Valproic Acid
  • Stavzor, Free
  • Valproate
  • valproic acid blood level
  • VPA blood level