Valproic Acid, Free and Total
Ordering Recommendation
Preferred test for therapeutic drug management in patients with renal failure or conditions that may alter albumin concentrations.
New York DOH Approval Status
Specimen Required
Timing of specimen collection: Pre-dose (trough) draw - At steady state concentration.
Plain red.
Separate serum from cells within 2 hours of collection. Transfer 2 mL serum to an ARUP Standard Transport Tube. (Min: 1 mL)
Refrigerated.
Light blue (citrate), gray (oxalate), green (heparin), K2EDTA plasma, tubes that contain liquid anticoagulant, or gel separator tubes.
After separation from cells: Ambient: 24 hours; Refrigerated: 1 week; Frozen: 1 month
Methodology
Quantitative Enzyme Multiplied Immunoassay Technique
Performed
Sun-Sat
Reported
1-4 days
Reference Interval
Test Number | Components | Therapeutic Range |
---|---|---|
0099308 | Valproic Acid, Total | Therapeutic Range: 50-125 µg/mL Toxic: Greater than 150 µg/mL |
0099791 | Valproic Acid, Free | Effective November 18, 2013 Therapeutic Range: 7-23 µg/mL Toxic: Greater than 30 µg/mL |
0099309 | 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.
FDA
Note
Hotline History
CPT Codes
80164; 80165
Components
Component Test Code* | Component Chart Name | LOINC |
---|---|---|
0099308 | Valproic Acid, Total | 4086-5 |
0099309 | Valproic Acid, Percent Free | 32283-4 |
0099791 | Valproic Acid, Free | 4087-3 |
Aliases
- Depacon
- Depakene, Free
- Depakote, Free
- Dipropylacetic Acid
- Eplim
- Free Valproate
- Free Valproic Acid
- Free VPA
- Orlept
- Protein Free Valproic Acid
- Stavzor, Free
- Valproate
- valproic acid blood level
- VPA blood level