Preferred test for therapeutic drug management in patients with renal failure or conditions that may alter albumin concentrations.
Quantitative Enzyme Multiplied Immunoassay Technique
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