Preferred test for therapeutic drug management in patients with renal failure or conditions that may alter albumin concentrations.
Quantitative Enzyme Multiplied Immunoassay Technique
New York DOH Approval Status
Timing of specimen collection: Pre-dose (trough) draw - At steady state concentration.
Separate serum from cells within 2 hours of collection. Transfer 2 mL serum to an ARUP Standard Transport Tube. (Min: 1 mL)
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
|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|
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.
|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|
- Depakene, Free
- Depakote, Free
- Dipropylacetic Acid
- Free Valproate
- Free Valproic Acid
- Free VPA
- Protein Free Valproic Acid
- Stavzor, Free
- valproic acid blood level
- VPA blood level