VALPROIC ACID, FREE
1 Red Top//1.0 mL serum. Centrifuge, separate and refrigerate. Do not collect in SST tube.
Alternate specimen: lavender EDTA
Room Temp 48 hours; Refrigerated 7 days
2-3 days Performed Mon-Sat
Analysis of Free Valproic Acid levels may be useful in delineating the cause of toxicity when the total concentration is not excessive. Geriatric patients often exhibit hypoalbuminemia, which results in a marked decrease in protein-binding sites for drugs. The clinical symptoms of drug intoxication may not be apparent, but may manifest themselves in impaired cognitive function and confusion. Therefore, it is important to evaluate both total and free concentrations.