Valproic Acid, Free

Test Code

VALPF

Quest Code

3314

CPT Codes
80165

Preferred Specimen

3 mL serum collected in a red-top tube (no gel)

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

Minimum Volume

1 mL

Other Acceptable Specimens

Serum collected in: No additive (royal blue-top) tube • Plasma collected in: EDTA (lavender-top) or EDTA (royal blue-top) tube

Instructions

Do not use gel barrier tubes. Centrifuge and immediately separate serum or plasma specimens from the cells into clean transport tube.

Transport Container

Transport tube

Transport Temperature

Refrigerated (cold packs)

Specimen Stability

Room temperature: 48 hours
Refrigerated: 7 days
Frozen: 60 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Serum separator tube (SST)

Methodology
Immunoassay (IA)

Setup Schedule

Day shift or Night shift Daily

Report Available

1 day

Reference Range

4.8-17.3 mg/L

Clinical Significance

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.

Performing Laboratory

Quest Diagnostics LLC

200 Forest Street, 3rd Floor, Suite B

Marlborough, MA 01752-3023

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.