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Test Code VALPF Valproic Acid, Free, Serum

Performing Laboratory

Quest Nichols-Valencia


Fluorescence Polarization Immunoassay (FPIA)

Reference Values

5.0-10.0 mg/L

Test Classification and CPT Coding



LOINC: 4087-3

Specimen Required

Container/Tube:  Plain, red-top tube(s)

Specimen:  3 mL of serum (1 mL min)

Transport Temperature:  Refrigerate


Stability: 7 Days Refrigerated

                60 Days Frozen


Do not use gel barrier tubes. Centrifuge and immediately separate serum or plasma specimens from the cells into clean, plastic, screw-cap vial(s).
Do not use serum separator tubes. Submission of a serum separator tube will result in cancellation


Patient Preparation

Avoid contact of samples with plasticizers, varnishes, paint fumes, and fatty acids. Collect as a trough just before next dose (Optimum time to collect sample: 1 hour before next dose.).

Day(s) and Time(s) Performed

Monday through Saturday


TAT: 2 - 4 Days

Computer Interface Code

PDM #  5400266

Usedn For

Valproic acid is used as an anticonvulsant to treat certain types of seizures, to prevent migraine headahces, and to treat various psychiatric illnesses such as bipolar disorder and aggression. Drugs that compete from protein-binding sites with valproic acid, can increase the concentration of valproic acid. Measurement of the free concentration is useful if toxicity is suspected.